No. 439 

Technical Report Series 

NATIONAL TOXICOLOGY PROGRAM 

(CAS NO. 298-59-9) 

METHYLPHENIDATE HYDROCHLORIDE 

STUDIES OF 

TOXICOLOGY AND CARCINOGENESIS 

IN F344/N RATS AND B6C3Fl MICE 

(FEED STUDIES) 

National Institutes of Health 

Public Health Service 

U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES 
FOREWORD 

applied research and to biological assay development and validation. 

relevant programs, staff, and resources from these Public Health Service agencies relating to basic and 

Carcinogenesis Bioassay Testing Program, NCI, was transferred to the NIEHS. The NTP coordinates the 

Institute for Occupational Safety and Health (NIOSH), Centers for Disease Control. In July 1981, the 

National Center for Toxicological Research (NCTR), Food and Drug Administration; and the National 

the National Institute of Environmental Health Sciences (NEHS), National Institutes of Health; the 

Health and Human Services (DHHS): the National Cancer Institute (NCI), National Institutes of Health; 

The National Toxicology Program (NTP) is made up of four charter agencies of the U.S. Department of 

prevention of disease. 

chemicals. This knowledge is used for protecting the health of the American people and for the primary 

The NTP develops, evaluates, and disseminates scientific information about potentially toxic and hazardous 

quality assurance audits before being presented for public review. 

Laboratory Practice Regulations, and all aspects of the chronic studies were subjected to retrospective 

and chronic studies were conducted in compliance with Food and Drug Administration (FDA) Good 

accordance with the Public Health Service Policy on Humane Care and Use of Animals. The prechronic 

exceed all applicable federal, state, and local health and safety regulations. Animal care and use were in 

were conducted in compliance with NTP laboratory health and safety requirements and must meet or 

The studies described in this Technical Report were performed under the direction of the NIEHS and 

chemical’s carcinogenic potential. 

human exposure, level of production, and chemical structure. Selection per se is not an indicator of a 

Chemicals selected for NTP toxicology and carcinogenesis studies are chosen primarily on the bases of 

carcinogenic activity, of selected chemicals in laboratory animals (usually two species, rats and mice). 

These studies are designed and conducted to characterize and evaluate the toxicologic potential, including 

Management, NIEHS, P.O. Box 12233, MD AO-01, Research Triangle Park, NC 27709 (919-541-3419). 

copies of this Technical Report are available without charge while supplies last from NTP Central Data 

U.S. Department of Commerce, 5285 Port Royal Road, Springfield, VA 22161 (703-487-4650). Single 

These NTP Technical Reports are available for sale from the National Technical Information Service, 
TOXICOLOGY AND CARCINOGENESIS 

ON THE 

NTP TECHNICAL REPORT 

STUDIES OF 

METHYLPHENIDATE HYDROCHLORIDE 

(CAS NO. 298-59-9) 

IN F344/N RATS AND B6C3Fl MICE 

(FEED STUDIES) 

Research Triangle Park, NC 27709 

P.O. Box 12233 

NATIONAL TOXICOLOGY PROGRAM 

July 1995 

NIH Publication No. 95-3355 

NTP TR 439 

National Institutes of Health 

Public Health Service 

U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES 
2 Methylphenidate Hydrochloride, NTP TR 439 

CONTRIBUTORS 

National Toxicology Program 

Evaluated and interpreted results and reported findings 

K.L. Witt, M.S., Oak Ridge Associated Universities 

D.B. Walters, Ph.D. 

B.A. Schwetz, D.V.M., Ph.D. 

J.H. Roycroft, Ph.D. 

G.N. Rao, D.V.M., Ph.D. 

J.K. Haseman, Ph.D. 

J.R. Hailey, D.V.M. 

T.J. Goehl, Ph.D. 

S.L. Eustis, D.V.M., Ph.D. 

J.K. Dunnick, Ph.D. 

J.R. Bucher, Ph.D. 

D.A. Bridge, B.S. 

G.A. Boorman, D.V.M., Ph.D. 

C.J. Alden, PbD. 

Hazleton Laboratories 

evaluated pathology jindings 

Conducted 14-doy and 13-week studies, 

T.A. Jackson, D.V.M., Ph.D. 

B.H. Boysen, D.V.M., M.Sc. 

K.M. MacKenzie, Ph.D., Principal Investigator 

TSI Mason Research Institute 

Conducted 2-year studies, evaluated pathology findings 

EA. Voelker, D.V.M., M.S., A.C.V.P. 

L.E. Sendelbach, Ph.D., D.A.B.T. 

A. Russfield, M.D. 

A.G. Braun, Sc.D., Principal Investigator 

Experimental Pathology Laboratories, Inc. 

K. Yoshitomi, D.V.M., Ph.D. 

J.F. Hardisty, D.V.M., Principal Investigator 

Provided pathology quality assurance 

Dynamac Corporation 

S. Brecher, Ph.D., Principal Investigator 

Prepared quality assurance audits 

NTP Pathology Working Group 

Evaluated slides, prepared pathology report on rats 

K. Yoshitomi, D.V.M., Ph.D. 

K. Takahashi, D.V.M., M.Sc., Ph.D. 

C.C. Shackelford, D.V.M., M.S., Ph.D. 

R.A. Herbert, D.V.M., Ph.D. 

J.R. Hailey, D.V.M. 

S.L. Eustis, D.V.M., Ph.D. 

T.A. Bertram, D.V.M., Ph.D. 

D.G. Goodman, V.M.D., Chair 

(I1 February 1992) 

Experimental Pathology Laboratories, Inc. 

National Toxicology Program 

National Toxicology Program 

National Toxicology Program 

National Toxicology Program 

National Toxicology Program 

Proctor & Gamble, Co. 

PATHCO, Inc. 

J.R. Hailey, D.V.M. 

Chemical Industry Institute of Toxicology 

J. Everitt, D.V.M. 

National Toxicology Program 

S.L. Eustis, D.V.M., Ph.D. 

Takeda Chemical Industries, Ltd. 

F. Chatani, Ph.D. 

Purdue University 

W.W. Carlton, D.V.M., Ph.D. 

PATHCO, Inc. 

D.G. Goodman, V.M.D., Chair 

(I 7 March 1992) 

Evaluated slides, prepared pathology report on mice 

National Toxicology Program 

R.A. Herbert, D.V.M., Ph.D. 

National Toxicology Program 

Experimental Pathology Laboratories, Inc. 

K. Yoshitomi, D.V.M., Ph.D. 

National Toxicology Program 

C.C. Shackelford, D.V.M., M.S., Ph.D. 

Biotechnical Services, Inc. 

Prepared Technical Repon 

H.A. Lindsay, B.A. 

T.A. King-Hunter, B.S. 

S.R. Gunnels, M.A. 

D.D. Lambright, Ph.D., Principal Investigator 
3 

CONTENTS 

ABSTRACT ................................................................... 5 

............... 

SUMMARY OF TECHNICAL REPORTS REVIEW SUBCOMMITTEE COMMENTS 

TECHNICAL REPORTS REVIEW SUBCOMMITTEE 

EXPLANATION OF LEVELS OF EVIDENCE OF CARCINOGENIC ACTIVITY 9 

11 

................................... 10 

........... 

INTRODUCTION .............................................................. 

MATERIALSANDMETHODS .................................................... 

RESULTS .................................................................... 

DISCUSSION AND CONCLUSIONS ................................................ 

REFERENCES ................................................................ 

APPENDIX A Summary of Lesions in Male Rats in the 2-Year Feed Study 

of Methylphenidate Hydrochloride ..................................... 

APPENDIX B Summary of Lesions in Female Rats in the 2-Year Feed Study 

of Methylphenidate Hydrochloride ..................................... 

APPENDIX C Summary of Lesions in Male Mice in the 2-Year Feed Study 

of Methylphenidate Hydrochloride ..................................... 

APPENDIX D Summary of Lesions in Female Mice in the 2-Year Feed Study 

of Methylphenidate Hydrochloride ..................................... 

APPENDIX E Genetic Toxicology ................................................. 

APPENDIX F Organ Weights and Organ-Weight-to-Bodyweight Ratios .................... 

APPENDIX G Hematology and Clinical Chemistry Results .............................. 

APPENDIX H Special Studies .................................................... 

APPENDIX I Chemical Characterization and Dose Formulation Studies ................... 

APPENDIX J Feed and Compound Consumption ..................................... 

APPENDIX K Ingredients. Nutrient Composition. and Contaminant Levels 

in NIH-07 Rat and Mouse Ration ..................................... 

63 

57 

31 

21 

13 

71 

113 

151 

279 

265 

261 

253 

243 

231 

189 

285 

APPENDIX L Sentinel Animal Program ............................................ 291 
4 Methylphenidate Hydrochloride, NTP TR 439 
5 

ABSTRACT 

0 

METHYLPHENIDATE HYDROCHLORIDE 

CAS NO. 298-59-9 

Chemical Formula: C,.,H,$rlO,. HCl Molecular Weight: 269.77 

Trade names: Centedrin; Centedrine; Ciba; Meridil; Phenidylate; Ritalin; Ritalin Hydrochloride 

Synonyms: a-phenyl-2-piperidineacetic acid methyl ester hydrochloride; methylphenidylacetate hydrochloride; 

a-phenyl-a-(2-piperidyl)acetic acid methyl ester hydrochloride; methyl a-phenyl-a-(2-piperidyl)acetate hydrochloride 

Chinese hamster ovary cells. 

conducted in Salmonella typhimurium and in cultured 

13 weeks, or 2 years. Genetic toxicology studies were 

female F344/N rats and B6C3F, mice for 14 days, 

(USP grade) ad libitum in feed to groups of male and 

ed by administering methylphenidate hydrochloride 

Toxicology and carcinogenicity studies were conductis the most common route of human exposure. 

on its potential carcinogenicity. Oral administration 

use in human medicine and because of lack of data 

National Cancer Institute because of its widespread 

by the Food and Drug Administration and the 

activity disorders. This drug was nominated for study 

treatment of narcolepsy and attention deficit hyperMethylphenidate hydrochloride is a drug used in the 

female rats were 9% lower than those of the conThe final mean body weights of 4,000 ppm male and 

14 days. All rats survived to the end of the study. 

4,000 ppm methylphenidate hydrochloride for 

were fed diets containing 0, 16, 62, 250, 1,000, or 

Groups of five male and five female F344/N rats 

14-DAY STUDY IN RATS 

trophy was observed in 4,000 ppm males and females. 

lesions were observed; however, centrilobular hyperweek of treatment. No treatment-related gross 

animals appeared to be normal during the second 

activity in 4,000 ppm males and females, but these 

during the first week of the study included hypergreater than those of the controls. Clinical findings 

4,000 ppm males and females were significantly 

trols. Absolute and relative liver weights of 

and relative liver weights of all exposed groups of 

icantly lower than those of the controls. Absolute 

and 4,000 ppm males and females were also signifcontrols, and the mean body weight gains of 1,000 

4,000 ppm females was 11% lower than that of the 

the end of the study. The final mean body weight of 

second week of the study; all other mice survived to 

14 days. Three 4,000 ppm males died during the 

4,000 ppm methylphenidate hydrochloride for 

were fed diets containing 0, 16, 62, 250, l,OOO, or 

Groups of five male and five female B6C3Fl mice 

14-DAY STUDY IN MICE 
6 Methylphenidate Hydrochloride, NTP TR 439 

4,OOO ppm and in males exposed to 250 ppm. 

observed in males and females exposed to 1,OOO or 

4,OOO ppm males. Hepatocellular hypertrophy was 

of the renal tubule epithelium were observed in two 

some 4,OOO ppm males. Degeneration and necrosis 

observed during the second week of the study in 

greater than those of the controls. Hyperactivity was 

males and of 4,OOO ppm females were significantly 

vocalization during handling periods. 

sensitivity to touch, hyperactivity, and increased 

1,000 and 2,000 ppm females included slight hyper150 mgkg per day (females). Clinical findings in 

body weight per day (males) or 9, 18, 30, 70, or 

130 mg methylphenidate hydrochloride per kilogram 

received approximate doses of 8, 15, 30, 70, or 

exposed to 125, 250, 500, l,OOO, or 2,000 ppm 

by exposed and control groups was similar. Rats 

during the remainder of the study feed consumption 

by 2,OOO ppm rats was less than that by controls, but 

During the first week of the study, feed consumption 

and females were similar to those of the controls. 

controls. Final mean body weights of exposed males 

females were significantly lower than those of the 

2,OOO ppm males and females and of 250 ppm 

survival. Mean body weight gains of 500, l,OOO, and 

13 weeks. There were no chemical-related effects on 

2,OOO ppm methylphenidate hydrochloride for 

fed diets containing 0, 125, 250, 500, l,OOO, or 

Groups of 10 male and 10 female F344/N rats were 

ISWEEK STUDY IN RATS 

pathologic lesions. 

or females, nor were there treatment-related histodensity, or nose-to-rump lengths were noted in males 

chemical-related differences in bone length, bone 

weights of 1,000 ppm males and females. No 

those of the controls, as were the relative liver 

males and females were significantly greater than 

Absolute and relative liver weights of 2,000 ppm 

those of the controls. During the first week of the 

exposed male and female groups were similar to 

controls. The final mean body weights of other 

females were significantly lower than those of the 

to 250, 500, l,OOO, or 2,OOO ppm and of 2,OOO ppm 

survival. Final mean body weights of males exposed 

13 weeks. There were no chemical-related effects on 

2,OOO ppm methylphenidate hydrochloride for 

fed diets containing 0, 125, 250, 500, l,OOO, or 

Groups of 10 male and 10 female B6C3Fl mice were 

13-WEEK' STUDY IN MICE 

observed. 

(females). No chemical-related clinical findings were 

(males) or 15, 30, 70, 125, or 260 mgkg per day 

doses of 15, 30, 70, 115, or 230 mgkg per day 

250, 500, l,OOO, or 2,OOO ppm received approximate 

the remainder of the study. Mice exposed to 125, 

groups was similar to that by the controls throughout 

than that by controls; feed consumption by exposed 

study, feed consumption by 2,OOO ppm mice was less 

chloride. 

to 500, 1,000, or 2,000 ppm methylphenidate hydroeration or necrosis were observed in males exposed 

Centrilobular hypertrophy and hepatocellular degenrelative liver weights of 125,250, and 500 ppm males. 

greater than those of the controls, as were the 

2,000 ppm males and females were significantly 

Absolute and relative liver weights of 1,000 and 

exposure group were evaluated at 9 or 15 months. 

2 years. As many as 10 male and 10 female rats per 

1,000 ppm methylphenidate hydrochloride for up to 

F344/N rats were fed diets containing 0, 100, 500, or 

1,OOO ppm. Groups of 70 male and 70 female 

the high dose selected for the 2-year rat study was 

weight gains in 2,000 ppm rats in the 13-week study, 

Based on the increased liver weights and lower body 

%YEAR STUDY IN RATS 

group-housed males exposed to 1,000 ppm. 

was an increased incidence of fighting among 

females). The only chemical-related clinical finding 

imate doses of 5,25, or 50 mgkg per day (males and 

phenidate hydrochloride in feed received approxRats exposed to 100, 500, or 1,OOO ppm methyl96%, 89%, or 78% (females) those of the controls. 

1,OOO ppm were 102%, 95%, or 90% (males) and 

body weights of rats exposed to 100, 500, or 

24% less than those of the controls. Final mean 

weights of 500 and 1,000 ppm females were 4% to 

of the study; during the same time period, mean body 

than those of the controls from week 30 to the end 

of 500 and 1,000 ppm males were 3% to 10% lower 

controls at the end of the study. Mean body weights 

Survival of exposed rats was similar to that of the 

Consumption, and Clinical Findings 

Survival, Body Weights, Feed and Compound 

15 months. 

or clinical chemistry parameters occurred at 9 or 

No biologically significant differences in hematology 

Hematology and Clinical Chemistry 
Methylphenidate Hydrochloride 

incidences were observed in male or female rats, 

significant chemical-related increases in neoplasm 

sidered to be related to chemical administration. No 

6/48; 1,OOO ppm, 5/50), and the decrease was condecreased (0 ppm, 15/49; 100 ppm, 13/50; 500 ppm, 

incidence of mammary gland fibroadenomas was 

In female rats exposed to 500 or 1,000 ppm, the 

Pathology Findings 

exposure group were evaluated at 9 or 15 months. 

2 years. As many as 10 male and 10 female mice per 

250, or 500 ppm methylphenidate hydrochloride for 

male B6C3Fl mice were fed diets containing 0, 50, 

study was 500 ppm. Groups of 70 male and 70 fe13-week study, the high dose selected for the 2-year 

gains observed in 1,OOO and 2,000 ppm mice in the 

Based on the liver toxicity and lower body weight 

%YEAR STUDY IN MICE 

chemical-related clinibl findings. 

80 mgikg per day (females). There were no 

60 mgkg body weight per day (males) or 8, 40, or 

feed were estimated to have received 6, 30, or 

250, or 500 ppm methylphenidate hydrochloride in 

(females) that of the controls. Mice exposed to 50, 

89%, or 93% (males) and 98%, 93%, or 97% 

of mice exposed to 50, 250, or 500 ppm were 97%, 

than those of the controls. Final mean body weights 

weights of 250 ppm females were 3% to 7% lower 

the study; during the same time period, mean body 

lower than those of the controls throughout much of 

of mice exposed to 250 or 500 ppm were 3% to 11% 

controls at the end of the study. Mean body weights 

Survival of exposed mice was similar to that of the 

Consumption, and Clinical Findings 

Survival, Body Weights, Feed and Compound 

15 months. 

or clinical chemistry parameters occurred at 9 or 

No biologically significant differences in hematology 

Hematology and Clinical Chemistry 

in the liver. A few hepatocellular neoplasms were 

istration of methylphenidate hydrochloride occurred 

The principal lesions associated with the adminPathology Findings 

7 

and exposed mice. 

hepatocellular carcinoma were similar among control 

females (6/49,10/48,10/49,28/50). The incidences of 

in 500 ppm males (18/50, 18/50, 16/50, 29/50) and 

incidences of hepatocellular adenoma also occurred 

1/50; 250 ppm, 1/50; 500 ppm, 5/50). Increased 

occurred in 500 ppm males (0 ppm, 0/5Q 50 ppm, 

females. Increased incidences of hepatoblastoma 

philic foci were increased in 500 ppm males and 

At the end of the 2-year study, incidences of eosinoin exposed groups were not significantly increased. 

and 15-month interim evaluations, but the incidences 

observed in control and exposed male mice at the 9- 

GENETIC TOXICOLOGY 

s9. 

by testing higher doses than were used in tests with 

laboratory did obtain a positive response without S9 

were not increased in the presence of S9, but one 

absence of S9 activation. Sister chromatid exchanges 

not consistently dependent upon the presence or 

chromosomal aberrations tests, positive results were 

in cultured Chinese hamster ovary cells. In the 

chromatid exchanges and chromosomal aberrations 

chloride was also tested for induction of sister 

metabolic activation (S9). Methylphenidate hydroTA1535, or TA1537, with or without exogenous 

Salmonella typhimurium strains TA97, TA98, TA100, 

Methylphenidate hydrochloride was not mutagenic in 

CONCLUSIONS 

neoplasms. 

mice based on the occurrence of hepatocellular 

phenidate hydrochloride in male and female B6C3Fl 

was some evidence of carcinogenic activity of methylF344/N rats receiving 100,500, or 1,OOO ppm. There 

methylphenidate hydrochloride in male or female 

there was no evidence of carcinogenic activity* of 

Under the conditions of these 2-year feed studies, 

eosinophilic foci. 

and female mice resulted in increased incidences of 

istration of methylphenidate hydrochloride to male 

incidence of mammary gland fibroadenomas. Adminhydrochloride was associated with a decrease in the 

Treatment of female rats with methylphenidate 

l Explanation of Levels of Evidence of Carcinogenic Activity is on page 9. A summary of the Technical Report Review Subcommittee 

comments and the public discussiorl on this Technical Report appears on page 11. 
8 Methylphenidate Hydrochloride, NTP TR 439 

Summary of the 2-Year Carcinogenesis and Genetic Toxicology Studies of Methylphenidate Hydrochloride 

Male Female Male Female 

F344/N Rats F344/N Rats B6C3F1 Mice B6C3F1 Mice 

Doses 

weights 

Final mean body 

rates 

2-Year survival 

effects 

Nonneoplastic 

effects 

Neoplastic 

incidences 

Decreased 

25, or 50 mgkglday] 

[approximately 5, 

1,OOO ppm in feed 

0,100,500, or 

lower than controls 

groups slightly 

500 and 1,000 ppm 

34/51 

2/50, 33/50, 34/50, 

None 

None 

None 

25, or 50 mgkglday] 

[approximately 5, 

1,OOO ppm in feed 

0,100,500, or 

controls 

groups lower than 

500 and 1,000 ppm 

39/50 

31/50, 32/50, 36/50, 

None 

None 

5/50 

15/49, 13/50, 6/48, 

fibroadenomas: 

Mammaw Eland 

30, or 60 mgkglday] 

[approximately 6, 

500 ppm in feed 

0, 50, 250, or 

250 PPm group 

lower than controls 

41/50 

45/50, 45/50, 44/50, 

14/50 

6/50, 8/50, 9/50, 

Eosinophilic foci: 

Hepatocellular 

- 

Liver: 

34/50 

24/50, 23/50, 26/50, 

hepatoblastoma: 

carcinoma, or 

adenoma, 

5/50; hepatocellular 

0/50, 1/50, 1/50, 

hepatoblastoma: 

18/50, 16/50, 29/50; 

adenoma: 18/50, 

None 

40, or 80 mgikglday] 

[approximately 8, 

500 ppm in feed 

0, 50, 250, or 

Exposed groups 

similar to controls 

44/50 

37/50, 35/50, 37/50, 

25/50 

3/49, 3/48, 8/49, 

Eosinophilic foci: 

Hepatocellular 

- 

Liver: 

11/48, 11/49,30/50 

carcinoma: 9/49, 

adenoma or 

hepatocellular 

10/48, 10/49, 2/50; 

adenoma: 6/49, 

None 

activity 

of carcinogenic 

Level of evidence No evidence 

Genetic toxicology 

No evidence Some evidence Some evidence 

Chromosomal aberrations 

Sister chromatid exchanges 

Salmonella ryphimurium gene mutation: Negative in strains TA97, TA98, TA100, TA1535, and TA1537 with and without S9 

Chinese hamster ovary cells in vim: Positive without S9 at first lab, positive with S9 at second lab 

Chinese hamster ovary cells in viao: Positive without S9; negative with S9 
Methylphenidate Hydrochloride 

EXPLANATION OF LEVELS OF EVIDENCE OF CARCINOGENIC ACTMTY 

analysis that extends beyond the purview of these studies. 

Thus, the actual determination of risk to humans from chemicals found to be carcinogenic in laboratory animals requires a wider 

available evidence, including animal studies such as those conducted by the NTF', epidemiologic studies, and estimates of exposure. 

such as the International Agency for Research on Cancer, assign a strength of evidence for conclusions based on an examination of all 

the conditions of the study and indicate that exposure to the chemical has the potential for hazard to humans. Other organizations, 

conducted under a limited set of conditions. Positive results demonstrate that a chemical is carcinogenic for laboratory animals under 

neoplasia than control animals, do not necessarily mean that a chemical is not a carcinogen, inasmuch as the experiments are 

evidence for conclusions regarding each study. Negative results, in which the study animals do not have a greater incidence of 

The National Toxicology Program describes the results of individual experiments on a chemical agent and notes the strength of the 

potency or mechanism. 

fie categories is selected to describe the findings. These categories refer to the strength of the experimental evidence and not to 

evidence of carcinogenic activity. For each separate experiment (male rats, female rats, male mice, female mice), one of the following 

and then revised in March 1986 for use in the Technical Report series to incorporate more specifically the concept of actual weight of 

evaluated because of major flaws (inadequate study). These categories of interpretative conclusions were first adopted in June 1983 

findings (equivocal evidence); one category for no observable effects (no evidence); and one category for experiments that canndt be 

observed in each experiment: two categories for positive results (clear evidence and some evidence); one category for uncertain 

Five categories of evidence of carcinogenic activity are used in the Technical Report series to summarize the strength of the evidence 

l Clear evidence of carcinogenic activity is demonstrated by studies that are interpreted as showing a dose-related 

malignancy. 

increase of benign neoplasms if there is an indication from this or other studies of the ability of such tumors to progress to 

(i) increase of malignant neoplasms, (ii) increase of a combination of malignant and benign neoplasms, or (iii) marked 

that required for clear evidence. 

increased incidence of neoplasms (malignant, benign, or combined) in which the strength of the response is less than 

l Some evidence of carcinogenic activity is demonstrated by studies that are interpreted as showing a chemical-related 

limitations, cannot be interpreted as valid for showing either the presence or absence of carcinogenic activity. 

increases in malignant or benign neoplasms. 

increase of neoplasms that may be chemical related. 

l Inadequate study of carcinogenic activity is demonstrated by studies that, because of major qualitative or quantitati6e 

l No evidence of carcinogenic activity is demonstrated by studies that are interpreted as showing no chemical-related 

l Equivocal evidence of carcinogenic activity is demonstrated by studies that are interpreted as showing a marginal 

borderline between two adjacent levels. These considerations should include: 

current understanding of long-term carcinogenesis studies in laboratory animals, especially for those evaluations that may be on the 

actual boundary of an individual category of evidence. Such consideration should allow for incorporation of scientific experience and 

When a conclusion statement for a particular experiment is selected, consideration must be given to key factors that would extend the 

l adequacy of the experimental design and conduct; l occurrence of common versus uncommon neoplasia; l progression (or lack thereof) from benign to malignant neoplasia as well as from preneoplastic to neoplastic lesions; l some benign neoplasms have the capacity to regress but others (of the same morphologic type) progress. At present, 

organ or tissue; 

course is to assume that benign neoplasms of those types have the potential to become malignant; 

it is impossible to identify the difference. Therefore, where progression is known to be a possibility, the most prudent 

l combining benign and malignant tumor incidence known or thought to represent stages of progression in the same 

l supporting information from proliferative lesions (hyperplasia) in the same site of neoplasia or in other experiments 

l metastases; 

l multiplicity in site-specific neoplasia; 

l latency in tumor induction; 

l in some cases, genetic toxicology. 

l structure-activity correlations; and 

l suxvival-adjusted analyses and false positive or false negative concerns; 

l concurrent control tumor incidence as well as the historical control rate and variability for a specific neoplasm; 

l statistical significance of the observed tumor increase; 

l presence or absence of dose relationships; 

(same lesion in another sex or species); 
10 Methylphenidate Hydrochloride, NTP TR 439 

TECHNICAL REPORTS REVIEW SUBCOMMITTEE 

NATIONAL TOXICOLOGY PROGRAM BOARD OF SCIENTIFIC COUNSELORS 

reviewing NTP studies: 

any institution, company, or governmental agency. In this capacity, subcommittee members have five major responsibilities in 

hydrochloride on June 22, 1993, are listed below. Subcommittee members serve as independent scientists, not as representatives of 

The members of the Technical Reports Review Subcommittee who evaluated the draft NTP Technical Report on methylphenidate 

e to ascertain that all relevant literature data have been adequately cited and interpreted, 

e to determine if the design and conditions of the NTP studies were appropriate, 

e to ensure that the Technical Report presents the experimental results and conclusions fully and clearly, 

e to judge the significance of the experimental results by scientific criteria, and 

l to assess the evaluation of the evidence of carcinogenic activity and other observed toxic responses. 

Kansas City, KS 

University of Kansas Medical Center 

Department of Pharmacology and Toxicology 

Curtis D. Klaassen, Ph.D., Chair 

Paul T. Bailey, Ph.D. 

Princeton, NJ 

Mobil Oil Corporation 

Environmental and Health Sciences Laboratory 

Louis S. BeliczQ, M.S., M.P.H.* 

Akron. OH 

United Rubber Workers International Union 

Department of Industrial Hygiene 

Arnold L. Brown, M.D. 

Madison, WI 

University of Wisconsin Medical School 

Oak Ridge, TN 

Oak Ridge National Laboratory 

Health and Safety Research Division 

Kowetha A. Davidson, Ph.D. 

Harold Davis, D.V.M., Ph.D., Principal Reviewer 

Pearl River, NY 

American Cyanamid 

Medical Research Division 

Daniel S. Longnecker, M.D.* 

Lebanon, NH 

Dartmouth Medical School 

Department of Pathology 

Boston, MA 

Dana-Farber Cancer Institute 

Harvard School of Public Health and 

Division of Biostatistics 

Louise Ryan, Ph.D., Principal Reviewer 

Ellen K. Silbergeld, Ph.D.* ' University of Maryland Medical School 

Baltimore, MD 

Robert E. Taylor, M.D., Ph.D., Principal Reviewer 

Washington, D.C. 

Howard University College of Medicine 

Department of Pharmacology 

Matthew J. van Zwieten, D.V.M., Ph.D. 

West Point, PA 

Merck Research Laboratories 

Department of Safety Assessment 

Jerrold M. Ward, D.V.M., Ph.D. 

Frederick, MD 

National Cancer Institute 

Lauren Zeise, Ph.D. 

Reproductive and Cancer Hazard Assessment Section 

Berkeley, CA 

California Environmental Protection Agency 

* Did not attend 
Methylphenidate Hydrochloride 11 

SUMMARY OF TECHNICAL REPORTS REVIEW SUBCOMMITTEE COMMENTS 

Park, NC. 

of Environmental Health Sciences, Research Triangle 

The review meeting was held at the National Institute 

Counselors Technical Reports Review Subcommittee. 

National Toxicology Program Board of Scientific 

date hydrochloride received public review by the 

toxicology and carcinogenesis studies of methylpheniOn June 22,1993, the draft Technical Report on the 

cellular adenomas. 

in B6C3Fl mice based on the occurrence of hepatoM44/N rats and some evidence of carcinogenic activity 

sions were: no evidence of carcinogenic activity in 

nonneoplastic lesions in mice. The proposed concluand commenting on chemical-related neoplastic and 

design, reporting on survival and body weight effects, 

rationale for study, describing the experimental 

chloride by discussing the uses of the chemical and 

and carcinogenesis studies of methylphenidate hydroDr. J.K Dunnick, NIEHS, introduced the toxicology 

interpret. 

good. He found the genetic toxicology data hard to 

stereochemistry related to metabolism was quite 

metabolism and certain selective aspects of the 

proposed conclusions. He thought the discussion of 

Dr. Taylor, a principal reviewer, agreed with the 

Health. 

are being conducted by the National Institutes of 

chloride and that ongoing studies of its other effects 

the carcinogenic potential of methylphenidate hydroShe noted that the purpose of this study was to assess 

during the study showed no effects on bone density. 

old at study initiation and that measurements taken 

responded that the animals were six to seven weeks 

measurements might have been useful. Dr. Dunnick 

were too old at study start and that bone density 

young children, she was concerned that the animals 

Dr. Ryan said that, because this drug is taken by 

based on hepatocellular neoplasms should be raised. 

discussion on whether the level of evidence in mice 

related. Dr. Ryan thought there needed to be more 

bers didn’t support calling this effect chemical 

effects of the chemical. Dr. Dunnick said the numthyroid neoplasms because of the perceived hormonal 

requested more detail on the trends for increased 

principle with the proposed conclusions. She 

Dr. Ryan, the second principal reviewer, agreed in 

would be included in the report. 

a chemical exists. He added that a revised write-up 

accepted agreement on what defines genotoxicity in 

Dr. E. Zeiger, NIEHS, said that no generally 

genetic toxicology assays were positive. 

strains assayed were all negative, while some other 

explained that, in this study, the five Salmonella 

genetic toxicology of the chemical. Dr. Dunnick 

of results without a unifying conclusion regarding the 

the genetic toxicology section was too much a litany 

and malignant neoplasm. Dr. Davis commented that 

and in the incidence of hepatoblastoma, a very rare 

of hepatocellular adenoma and carcinoma (combined) 

supported by dose-related increases in the incidence 

conclusion of clear evidence of carcinogenic activity is 

with the proposed conclusions for mice. He said a 

Dr. Davis, the third principal reviewer, did not agree 

dence. 

plasms, which did not increase the combined incioccurred in animals with other hepatocellular neobenign and because all of the hepatoblastomas 

the increased neoplasms in exposed animals were 

proposed conclusion, some evidence, because most of 

in mice. Dr. J.K. Haseman, NIEHS, defended the 

the conclusion to clear evidence of carcinogenic activity 

fence of rare neoplasms in males supported raising 

hepatocellular neoplasms in females and the occurDr. Ward also thought that the high incidence of 

some of this discussion be summarized in the report. 

adenomas and carcinomas. Dr. Davidson asked that 

hepatoblastomas should be to combine them with 

appropriate treatment for statistical analysis of the 

ered a more primitive variant. He said the most 

neoplasms, usually carcinomas, and may be considare generally observed within other hepatocellular 

database. Hepatoblastomas appear late in mice and 

that do not yet appear in the NTP historical control 

neoplasm, a few are being seen in mice from studies 

He said that, although little is known about this 

discussion about the nature of the hepatoblastomas. 

of evidence in mice, Dr. J.R. Hailey, NIEHS, led a 

In response to the reviewers’ concerns about the level 

written. Dr. Taylor seconded the motion, noting that 

revisions discussed and with the conclusions as 

methylphenidate hydrochloride be accepted with the 

Dr. Brown moved that the Technical Report on 
12 Methylphenidate Hydrochloride, NTP TR 439 

the wording at the end of the first paragraph of the (Drs. Bailey, Brown, Davidson, and Taylor) to three 

conclusions be changed from "adenomas" to yes votes (Dm. Davis, Ward, and Zeise) with two 

"neoplasms." Dr. Zeise offered an amendment that abstentions (Drs. Ryan and van Zwieten). The 

the conclusion for male mice be changed to clear original motion by Dr. Brown, including the wording 

evidence of carcinogenic activity. Dr. Ward seconded change, was then accepted by eight yes votes with one 

the amendment, which was defeated by four no votes abstention (Dr. van Zwieten). 
13 

INTRODUCTION 

0 

METHYLPHENIDATE HYDROCHLORIDE 

CAS NO. 298-59-9 

Chemical Formula: C,,H,,,NO,.HCI . Molecular Weight: 269.77 

Trade names: Centedrin; Centedrine; Ciba; Meridil; Phenidylate; Ritalin; Ritalin Hydrochloride 

Synonyms: a-phenyl-Zpiperidineacetic acid methyl ester hydrochloride; methylphenidylacetate hydrochloride; 

a-phenyl-a-(2-piperidyl)acetic acid methyl ester hydrochloride; methyl a-phenyl-a-(2-piperidyl)acetate hydrochloride 

et al., 1987). 

the protonated form at physiological pH (Patrick 

it is estimated that more than 90% of the drug is in 

The pK, of methylphenidate hydrochloride is 8.5 and 

extensively in basic solutions (Padmanabhan, 1981). 

is relatively stable in acidic solutions but is degraded 

ethanol and slightly soluble in chloroform. The drug 

to 216" C. It is soluble in water, methanol, and 

fine crystalline powder with a melting point of 212" 

Methylphenidate hydrochloride is a white, odorless, 

CHEMICAL AND PHYSICAL PROPERTIES 

active pharmacologically than the erythro isomers, 

tiomers of methylphenidate hydrochloride are more 

contain only the threo racemate. The threo enanand I-qthro. Current pharmaceutical products 

rise to four optical isomers: d-threo, I-threo, d-erythro, 

metrical carbon atoms (two chiral centers) which give 

containing a methyl ester and possessing two asymMethylphenidate hydrochloride is a secondary amine 

(Maxwell et al., 1970; Patrick et al., 1987). 

be responsible for the therapeutic action of the drug 

et al., 1987). The d-threo enantiomer is believed to 

I-enantiomer (Szporny and Gbrbg, 1961; Srinivas 

and d-threo-methylphenidate is more active than the 

(Padmanabhan, 1981). 

is then converted to methylphenidate hydrochloride 

methanol to yield the methyl ester free base, which 

a-phenyl-2-piperidineacetic acid and reacted with 

solution and, in the same reaction, is hydrolyzed to 

racemic mixture by heating in sodium hydroxide 

diastereoisomeric mixture is converted to a threo 

mixture of a-phenyl-2-piperidineacetamide. The 

product is hydrogenated to yield a diastereoisomeric 

sulfuric acid to a-phenyl-2-pyridineacetamide; this 

hydrolyzing a-phenyl-2-pyridineacetonitrile in dilute 

Methylphenidate hydrochloride is prepared by 

derivative structurally related to amphetamine. 

Methylphenidate hydrochloride is a piperidine 
14 Methylphenidate Hydrochloride, NTP TR 439 

United-States (American Druggist, 1990). 

200 most often dispensed prescription drugs in the 

1.0 mg/kg. Methylphenidate (Ritalin) is among the 

Doses used in children usually range from 0.3 to 

exceed 60 mg daily (Hoffman and Lefkowitz, 1990). 

twice daily and the dosage for children should not 

initial dosage recommended for children is 5 mg 

adult dosage is 10 mg given 2 or 3 times daily; the 

release preparations are also available. The usual 

phenidate hydrochloride are available; sustained 

Tablets which contain 5, 10, or 20 mg of methyl- 

(Gurian and Rosowsky 1990; Heath et al., 1990). 

(ADHD) in children (Barkley et al., 1990) and adults 

lepsy and attention-deficit hyperactivity disorders 

Methylphenidate is used in the treatment of narcoUSE AND HUMAN EXPOSURE 

Safer and Krager, 1988a,b). 

than in girls (Segal et al., 1976; Srinivas et al., 1987; 

ADHD is three to six times more common in boys 

7 years for students starting treatment in high school. 

children, 4 years for children in middle schools, and 

chloride was 2 years for elementary school-age 

duration of treatment with methylphenidate hydroconducted in Baltimore county schools, the average 

93% of ADHD cases. During a 10-year survey 

hydrochloride is prescribed as the drug of choice in 

are being treated for ADHD. Methylphenidate 

(1 million) of U.S. elementary school-age children 

Barkley et al. (1990) estimated that 3% to 6% 

(Goodman and Gilman’s, 1980). 

Abuse Prevention and Control Act of 1970 

is a Schedule I1 drug under the Comprehensive Drug 

potential for abuse, methylphenidate hydrochloride 

mid-1950’s (The NDA Book, 1990). Because of the 

Methylphenidate hydrochloride was first used in the 

PHARMACOLOGY 

(1954), looking for analogues of amphetamine, 

compliance and academic performance. Meier et al. 

where it was reported that this treatment increased 

behavior disorders was first noted by Bradley (1937), 

therapy (amphetamine) in the treatment of children’s 

Greenhill, 1992). The usefulness of stimulant 

understood (Zametkin and Rapoport, 1987; 

ioral disorder of unknown etiology, is not fully 

attention deficit disorders, a heterogeneous behav1990), its pharmacologic action in the treatment of 

and Werner, 1954; Meier et al., 1954; Calis et al., 

hydrochloride were first described in 1954 (Brown 

While the pharmacologic actions of methylphenidate 

a stimulant drug. 

reported that methylphenidate could also be used as 

Luthman et al., 1989). 

phenidate or amphetamine (Shaywitz et al., 1976; 

ameliorated by the administration of methylrat causes hyperactivity, and this hyperactivity is 

dopamine with 6-hydroxydopamine in the neonatal 

levels in the brain. Selective depletion of brain 

rodents and focused on the effects on catecholamine 

hyperactivity disorder (ADHD) were conducted in 

methylphenidate in the treatment of attention-deficit 

Studies to determine the pharmacologic effects of 

anorexic effect (Barone et al., 1979). 

phenidate hydrochloride appears to have a transient 

effect may develop (Fregly and Black, 1964). Methyl- 

(82 mgkg per day) for 5 days, but tolerance to this 

fed diets containing 2,000 ppm methylphenidate 

spontaneous activity was also noted when rats were 

monkeys caused stimulatory effects. Enhanced 

doses of 20 mgkg in mice and 2.5 mgkg in squirrel 

1954). Warawa et. al. (1975), reported that oral 

such as light, noise, and touch (Brown and Werner, 

shortened reaction times to environmental stimuli 

scratching, eating, chewing, and drinking) and 

to 40 mgkg resulted in increased activities (licking, 

and rabbits found that oral doses of approximately 10 

Studies of methylphenidate in mice, rats, guinea pigs, 

serotonin in the brain (Bhattacharyya et al., 1980). 

dopamine levels and decreases in norepinephrine and 

and these effects are correlated with an increase in 

activity and stereotyped behavior in normal animals 

Methylphenidate increases spontaneous motor 

but not those of amphetamine (Patrick et al., 1987). 

that reserpine antagonizes methylphenidate effects 

ence between amphetamine and methylphenidate is 

catecholamines (Finn et al., 1990). Another differstimulating the release of stored or granular pools of 

amines into the synaptic cleft, and methylphenidate 

stimulating the release of newly synthesized catecholactions on dopaminergic neurons with amphetamine 

rodent are thought to be related to their indirect 

The stimulatory effects of methylphenidate in the 

as are seen with amphetamine and methylphenidate, 

neurons, and increases in brain dopamine lvels, such 

inhibiting factor (PIF) is controlled by dopaminergic 

neuroendocrine functions. Hypothalamic prolactindopamine levels in the brain, it may mediate other 

As a consequence of methylphenidate’s effects on 
introduction 15 

et al., 1983). 

decreases in serum prolactin (Archer, 1977; Leong 

may increase the release of PIF, resulting in 

found in ADHD (Shenker, 1992). 

methylphenidate may remedy a secondary function 

catecholamine system. The pharmacologic effects of 

the primaly defect of ADHD may not lie in the 

methylphenidate treatment (Ciarantello, 1993), and 

et al., 1993). Not all symptoms of ADHD respond to 

hormone in a subset of ADHD patients (Hauser 

associated with generalized resistance to thyroid 

familial predisposition and that this disorder is 

Recent studies suggest that ADHD may have a 

ABSORPTION, DISTRIBUTION, 

(Faraj et al., 1974). 

oxomethylphenidate and p-hydroxymethylphenidate 

dogs is microsomal oxidation of methylphenidate to 

The primary route of metabolism in rats, mice, and 

chloride metabolism are summarized in Figure 1. 

two major pathways of methylphenidate hydrofound in rats and dogs are presented in Table 1; the 

tion. Metabolites of methylphenidate hydrochloride 

In these species, urine is the primary route of excrehas been studied in rats, mice, dogs, and monkeys. 

The metabolism of methylphenidate hydrochloride 

Experimental Animals 

METABOLISM, AND EXCRETION 

serum was 8:l (Gal et al., 1977; Patrick et al., 1984). 

ratio of methylphenidate in brain tissue to that in 

intravenously or orally. Within 1 to 5 minutes, the 

administered 1 mg/kg methylphenidate hydrochloride 

et al., 1983). In tissue distribution studies, rats were 

3 and 10 mgkg, respectively, is 2 to 3 hours (Wargin 

in monkeys and rats administered oral doses of 

imately 200 ng/mL. The plasma elimination half-life 

hour peak plasma concentrations reach approxweight is absorbed in 1 hour, and that within that 

10 mg methylphenidate hydrochloride per kg body 

Studies in rats indicate that 19% of an oral dose of 

radiolabel was also excreted in the bile. Ritalinic 

and 30% to 40% in the feces; a significant amount of 

eliminated 50% to 60% of the radiolabel in urine 

phenidate hydrochloride orally or intraperitoneally 

Rats administered 10 to 20 mgikg 14C-methylet al., 1974; Egger et al., 1981). 

were the products of aromatic hydroxylation (Faraj 

bolic pathway; more than 50% of the metabolites 

Microsomal oxidation was the predominant meta60% of an oral dose in urine within 48 hours. 

metabolites. Mice and dogs also excreted 50% to 

conjugate (10%) were identified as the major urinary 

p-hydroxyritalinic acid (19%) and its glucuronide 

acid (a-phenyl-2-piperidineacetic acid) (36%) and 

phenidate (Patrick et al., 1987). 

not produce the pharmacologic activity of methylthat administration of these metabolites to rats does 

methylphenidate, and 6-oxomethylphenidate indicate 

compound. Studies with ritalinic acid, p-hydroxyhydrochloride appear to result from. the parent 

The pharmacologic actions of methylphenidate 

(Duerson et al., 1988; NTP, 1990). 

present studies in connection with liver toxicity 

for the sex and species differences observed in the 

that metabolic differences alone could not account 

between male and female mice. This finding suggests 

mice. However, no such differences were observed 

different from those observed in the urine of male 

metabolites observed in the urine of male rats were 

chromatography peaks from urine suggested that 

Quantitation of radioactive high-performance liquid 

between species in the rate or route of excretion. 

statistically significant differences were observed 

was excreted in the urine within 24 hours. No 

approximately 80% of methylphenidate administered 

and mice. In all dose groups of rats and mice, 

trations occurred in the liver, kidney, and lung of rats 

sition. The highest methylphenidate tissue concenof male mice) could be attributed to chemical dispopresent studies (toxicity was most severe in the liver 

observed in connection with liver toxicity in the 

study was to determine if sex and species differences 

19, or 35 mgkg (to mice). The overall aim of the 

of single doses of 7, 35, or 70 mgkg (to rats) or 2.1, 

phenidate hydrochloride following the administration 

distribution, metabolism, and excretion of methyllabeled material was used to trace absorption, 

rats and male and female B6C3Fl mice. The radiochloride was administered by gavage to male F344/pJ 

Program, [acetic acid-2-14C]-methylphenidate hydroIn studies conducted by the National Toxicology 
16 Methylphenidate Hydrochloride, NTP TR 439 

Methylphenidate Hydrochloride Metabolites Identified in Rats, Dogs, and Humansa 

TABLE 1 

Dose Route 

(Hours) 

Time 

(% of Urine) 

Metabolite 

0-24 

0-48 

Intraperitoneal 0-48 

Oral 0-8 

Intravenous 

Oral or Intravenous 

0-5 

0-24 

acid glucuronide (10%); Unknown (20%) 

Carbamide methylphenidate (1%); p-Hydroxyritalinic 

5-Hydroxy-6-oxoritalinic acid (15%-17%); 

(7%-10%); 5-Hydroxy-6-oxomethylphenidate (2%); 

6-Oxomethylphenidate (1.5%); 6-Oxoritalinic acid 

Methylphenidate (1%); Ritalinic acid (35%-40%); 

glucuronide (10%) 

p-Hydroxyritalinic acid (19%); p-Hydroxyritalinic acid 

(1.8%); p-Hydroxymethylphenidate (3%); 

6-Oxomethylphenidate (<l%); 6-Oxoritalinic acid 

Methylphenidate (~1%); Ritalinic acid (36%); 

glucuronide (10%) 

p-Hydroxyritalinic acid (20%); p-Hydroxyritalinic acid 

(3%); p-Hydroxymethylphenidate (15%); 

6-Oxomethylphenidate (1.2%); 6-Oxoritalinic acid 

Methylphenidate (~1%); Ritalinic acid (27%); 

Unknown (3%) 

(2%-3%); p-Hydroxy-6-oxosulfonic acid (1%); 

methylphenidate (1%); p-Hydroxy-6-oxoglucuronide 

5-Hydroxy-6-oxoritalinic acid (4%); Carbamide 

4-Hydroxyd-oxomethylphenidate glucuronide (1%); 

5-Hydroxy-6-oxomethylphenidate glucuronide (12%); 

(26.5%); 6-Oxoglucuronide (20%); 

6-Oxomethylphenidate (1%); 6-Oxoritalinic acid 

Methylphenidate (0.3%); Ritalinic acid (23%); 

glucuronide ( c 1%) 

6-Oxoritalinic acid (30%); p-Hydroxyritalinic acid 

acid (2%); 6-Oxomethylphenidate (7%); 

p-Hydroxymethylphenidate (1.2%); p-Hydroxyritalinic 

Methylphenidate ( c 1%); Ritalinic acid (44%); 

p-Hydroxyritalinic acid glucuronide (c 1%) 

6-Oxoritalinic acid (c 1%, 1.5% intravenously); 

acid (2%); 6-Oxomethylphenidate (<1%); 

p-Hydroxymethylphenidate (e 1%); p-Hydroxyritalinic 

Methylphenidate (~1%); Ritalinic acid (80%); 

a Data are presented in Faraj et al. (1974) and Egger et al. (1981). No quantitative data are available for mice. 
Introduction 

0 0 

17 

6-Oxomethylphenidate 

Deesterification 

Conjugation or 

(Patrick el aL, 1987) 

Metabolic Pathways of Methylphenidate 

FIGURE 1 
18 Methylphenidate Hydrochloride, NTP TR 439 

imately 2 hours (Chan et al., 1980, 1983). 

idate administered intravenously or orally is approxnation half-life of a 10 to 20 mg dose of methylphen11% to 53% (Chan et d., 1983). The plasma elimibioavailability of methyIphenidate is estimated to be 

concentrations in approximately 2 hours. The oral 

gastrointestinal tract and attains peak plasma level 

Methylphenidate hydrochloride is absorbed from the 

Humans 

et al., 1987; Calis et aL, 1990). 

macologically inactive (Faraj et al., 1974; Patrick 

acid, the most common metabolite in man, is pharChan et al., 1980; Srinivas et al., 1987). Ritalinic 

form of esters, free acids, and conjugates (Table 1; 

compounds are then excreted in the urine in the 

form oxomethylphenidate (2% to 5%). These 

methylphenidate (4%) and microsomal oxidation to 

involve aromatic hydroxylation to form p-hydroxyritalinic acid. Other minor metabolic pathways 

carboxylic acid metabolite commonly known as 

pathway is deesterification to form the corresponding 

In humans, methylphenidate’s predominant metabolic 

1987). 

10 mgmethylphenidate hydrochloride (Srinivas et al., 

than those of the I-enantiomer after an oral dose of 

the d-enantiomer are approximately 8 times greater 

dose of 20 to 40 mg. Peak plasma concentrations of 

than those of the f-enantiomer after a single oral 

d-threo-methylphenidate were consistently higher 

enantiomers, Lim et al. (1986) found that levels of 

By measuring plasma concentrations of individual 

TOXICITY 

stimulation (Segal et al., 1976). 

at these dose levels is excessive central adrenergic 

Warawa et aL, 1975). The probable cause of death 

450 mag in mice (Karczmar and Howard, 1959; 

Werner, 1954; Padmanabhan, 1981) and from 60 to 

to range from 180 to 350 mg&g in rats (Brown and 

The oral LD,, of methylphenidate has been reported 

Experimental Animals 

doses of 35 or 100 mg/kg resulted in significant 

subcutaneously for 21 days to 5- to 7-day old rats at 

1975). Methylphenidate hydrochloride administered 

microsomal drug metabolism in vitro (Dayton et al., 

1965; Kabara et al., 1972) and weakly inhibits hepatic 

cholesterol levels in experimental animals (Kabara, 

Methylphenidate treatment lowers serum and brain 

(Greeley et af., 1980). 

reduction of serum thyroxine and triiodothyronine 

1990). 

considered mild (Barkley et aL, 1990, Calis et af., 

phenidate experience side effects, which are usually 

Fewer than half of the children treated with methylache, weight loss, and transient growth suppression. 

decreased appetite, insomnia, stomach ache, headtreatment for attention-deficit disorders include 

Side effects from methylphenidate hydrochloride 

Humans 

release. 

with the normal diurnal variation of growth hormone 

that methylphenidate hydrochloride may interfere 

1977). Barter and Kammer (1978) have speculated 

hormone (Brown and Williams, 1976; Aarskog er al., 

may cause an increase or a decrease in serum growth 

1976; Satterfield et al., 1979). Prolonged treatment 

effect of transient therapy (Safer et aL, 1975; Gross, 

growth that completely reverses any anti-growth 

discontinued, children seem to experience rapid 

When methylphenidate hydrochloride therapy is 

Roche et al., 1979; Mattes and Gittelman, 1983). 

istered methylphenidate (Safer er al., 1972, 1975; 

concerning retardation of growth in children adminClinical studies have provided conflicting information 

caused by methylphenidate (Goodman, 1972). 

rare and have not conclusively been shown to be 

after methylphenidate treatment, but these effects are 

Hepatotoxicity and cardiotoxicity have been reported 

&PRODUCmrE AND DEVELOPMENTAL 

phenidate hydrochloride had no apparent effect on 

alive, sex of live pups, and pup body weight. Methylper pair, live pups per litter, proportion of pups born 

were evaluated for both generations: fertility, litters 

1 week at sexual maturity. The following parameters 

hydrochloride in feed, they were cohabitated for 

tered the same concentrations of methylphenidate 

tion. The Fl generation was weaned and administo cohabitation and for 98 days following cohabita1,OOO ppm to male and female mice for 7 days prior 

istered in feed at concentrations of 120, 500, and 

1989). Methylphenidate hydrochloride was adminstudied using a continuous breeding protocol (NTP, 

fertility and reproduction in Swiss CD-l@ mice were 

The effects of methylphenidate hydrochloride on 

TOXICITY 
Introduction 19 

motility was reduced in 2,000 ppm mice. 

of male or female rats or mice, although sperm 

cause significant toxicity to the reproductive system 

(125,500, or 2,000 ppm in feed for 13 weeks) did not 

Morrissey et al. (1988) found that methylphenidate 

rodent sperm morphology and vaginal cytology, 

an evaluation of the effects of 25 chemicals on 

motility, morphology, or on female estrous cycle. In 

effect on parental or Fl epididymal sperm density, 

females. Methylphenidate hydrochloride had no 

noted in 1,000 ppm parental and F, males and 

generation. Some increases in liver weights were 

fertility or reproduction in either the parental or F, 

CARCINOGENICITY 

to 26 months (Giner-Sorolla et al., 1980). 

plasms or nonneoplastic lesions when evaluated at 25 

animals exhibited no increased incidences of neowere 1 week old until they were 18 months old; the 

(12.5 mg/kg/day) 4 days per week from the time they 

taining 100 mg/L N-nitrosomethylphenidate 

study, mice were administered drinking water conof neoplasms (Lijinsky and Taylor, 1975). In another 

at a dose of 12 mg/rat did not increase the incidence 

15 male and 15 female rats twice weekly for 50 weeks 

N-Nitrosomethylphenidate administered orally to 

idate hydrochloride reported in the literature. 

There are no carcinogenicity studies of methylphenExperimental Animals 

than expected (Selby et al., 1989). 

phenidate the number of cancers observed was less 

gram showed that in 529 patients receiving methyla cohort of 143,574 patients in a medical care proA review of'pharmacy records from 1969 to 1973 for 

Humans 

GENETIC TOXICITY 

indicate that the chemical is not a gene mutagen in 

either methylphenidate or its hydrochloride salt 

The limited mutagenicity data that are available for 

dose. 

mosomal aberrations were not well correlated with 

produced severe toxicity, and the increases in chrosister chromatid exchanges occurred at doses which 

both of these cytogenetic assays, the increases in 

hydrochloride gave statistically positive responses in 

the presence of S9. Although methylphenidate 

1987); chromosomal aberrations were also induced in 

the presence and absence of S9 (Galloway et al., 

treated with methylphenidate hydrochloride both in 

were induced in cultured Chinese hamster ovary cells 

et al., 1986). However, sister chromatid exchanges 

out S9 metabolic activation enzymes (Mortelmans 

Salmonella typhimurium when tested with and withwas not mutagenic in any of several strains of 

mammalian cells. Methylphenidate hydrochloride 

some potential for inducing clastogenic damage in 

bacteria or mammalian cells, but that it might have 

rats treated in vivo (Mirsalis et al., 1983). 

uled DNA synthesis in hepatocytes of Fischer 344 

in vitro. Methylphenidate did not induce unschedmouse lymphoma cells treated with methylphenidate 

damage or gene mutations occurred in W178Y 

(1983) reported that no induction of chromosomal 

treated with methylphenidate. However, Rudd et al. 

human lymphocytes obtained from pediatric patients 

chromatid exchange frequencies were elevated in 

data. Walker and Dumars (1977) reported that sister 

brief abstracts which include little or no supporting 

with methylphenidate (nonsalt) are limited to three 

Results of genotoxicity tests that were performed 

STUDY RATIONALE 

primary route of human exposure. 

route of administration was selected because it is the 

carcinogenicity studies for this chemical. The oral 

and because there were no adequate toxicity and 

drug in the treatment of attention-deficit disorders 

hydrochloride for study because it is a widely used 

Drug Administration nominated methylphenidate 

The National Cancer Institute and the Food and 
20 Methylphenidate Hydrochloride, NTP TR 439 
21 

MATERIALS AND METHODS 

METHYLPHENIDATE HYDROCHLORIDE 

CHARACTERIZATION OF 

PROCUREMENT AND 

Sciences (NIEHS). 

at the National Institute of Environmental Health 

the methylphenidate hydrochloride studies are on file 

MO). Reports on analyses performed in support of 

laboratory, Midwest Research Institute (Kansas City, 

analyses were conducted by the analytical chemistry 

d-threo and f-threo. Identity, purity, and stability 

the chemical is a racemate of two optical isomers: 

the 2-year studies. The USP designation implies that 

studies. Lot CMS86-166-001 was used throughout 

M1088 was used throughout the 14-day and 13-week 

Geigy Corporation (Summit, NJ) in two lots. Lot 

Pharmacopeia grade, was supplied gratis by CibaMethylphenidate hydrochloride, United States 

raphy, and high-performance liquid chromatography. 

titration of the amine group, thin-layer chromatogelemental analyses, Karl Fischer water analysis, 

lot was determined to be greater than 99% by 

magnetic resonance spectroscopy. The purity of each 

chloride by infrared, ultravioletbisible, and nuclear 

solid, were identified as methylphenidate hydroBoth lots of the chemical, a white, fine crystalline 

of 0.6%. 

chloride was detected above the USP specified limit 

lot. No a-phenyl-2-piperidineacetic acid hydroidineacetic acid hydrochloride was present in either 

used to determine if the impurity a-phenyl-ZpiperUSP XX thin-layer chromatographic method was 

mate of methylphenidate hydrochloride. A second 

concluded that both lots contained the threo racenot present at the 1% USP limit. Therefore, it was 

analysis confirmed that the erythro (d, 1) isomer was 

Results of a USP XX thin layer chromatographic 

was obtained based on the lack of optical activity. 

Confirmation that the test chemical was a racemate 

hydrochloride was stable as a bulk chemical for 

and these studies indicated that methylphenidate 

performance liquid chromatography was performed 

by the analytical chemistry laboratory. HighStability studies of the bulk chemical were performed 

raphy and titration of the amine group. 

studies using high performance liquid chromatogbulk chemical was confirmed during the 2-year 

chemical was stored at 20" to 24" C. Stability of the 

atures up to 60" C. At the study laboratory, the 

2 weeks when stored protected from light at temper4" C for up to 2 weeks. 

toxicity studies, dose formulations were stored at 

simulated animal cage conditions. During the 

for up to 7 days when exposed to air and light under 

lation was confirmed for at least 3 weeks at 5" C and 

was confirmed and the stability of the dose formuperformance liquid chromatography. Homogeneity 

analytical chemistry laboratory using high200 ppm dose formulation was performed by th,e 

(Table 11). Homogeneity and stability studies of the 

mixing methylphenidate hydrochloride with feed 

The dose formulations were prepared weekly by 

OF DOSE FORMULATIONS 

PREPARATION AND ANALYSIS 

results obtained by the study laboratory (Table IS). 

analytical chemistry laboratory agreed with the 

Results of periodic referee analyses performed by the 

value greater than 21% of the target concentration. 

within 10% of the target concentration, with no 

the dose formulations analyzed, 88% (146/167) were 

initially and then every 6 to 10 weeks (Table 14). Of 

2-year studies, the dose formulations were analyzed 

point, and end of the studies (Table 13). During the 

formulations were analyzed at the beginning, midanalyzed (Table 12). For the 13-week studies, dose 

the 14-day studies, only the initial formulation was 

high-performance liquid chromatography. During 

laboratory and analytical chemistry laboratory using 

phenidate hydrochloride were conducted at the study 

Periodic analyses of the dose formulations of methylbegan. Before the beginning of the studies, two male 

for 15 days and mice for 16 days before exposure 

an average of 5 weeks old. Rats were quarantined 

(Frederick, MD). At receipt, the rats and mice were 

obtained from Frederick Cancer Research Facility 

Male and female F344/N rats and B6C3Fl mice were 

14-DAY STUDIES 
22 Methylphenidate Hydrochloride, NTP TR 439 

evidence of disease. 

for parasite evaluation and gross observation for 

and two female rats and mice were randomly selected 

(Padmanabhan, 1981). 

value reported for rats in the literature 

body weight in rats and approximated the oral LD,, 

concentration was estimated to deliver 370 mgkg 

62, 250, 1,000, and 4,000 ppm. The 4,000 ppm 

studies were repeated with exposure levels of 0, 16, 

lack of toxicity in the initial 14-day studies, these 

weight (rats) or 160 mg/kg (mice). Because of the 

estimated to receive daily doses of 80 mg/kg body 

1,000 ppm methylphenidate hydrochloride were 

chemical administration. Rats and mice exposed to 

survival, and no target organ lesions attributed to 

were no treatment-related effects on body weight or 

1,000 ppm methylphenidate hydrochloride. There 

and mice received 0, 62.5, 125, 250, 500, or 

An initial 14-day study was conducted in which rats 

rized in Table 2. 

the study design and animal maintenance are summaweekly, and 16 hours prior to necropsy. Details of 

were weighed at the beginning of the studies, twice 

by cage was recorded twice weekly. The animals 

mice were recorded twice daily. Feed consumption 

housed five per cage. Clinical findings for rats and 

water were available ad libitum. Rats and mice were 

4,000 ppm methylphenidate hydrochloride. Feed and 

were fed diets containing 0, 16, 62, 250, 1,000, or 

Groups of five male and five female rats and mice 

livers and kidneys of all rats and mice. 

Histopathologic examinations were performed on the 

right kidney, right testis, and thymus were weighed. 

on all rats and mice. The brain, heart, liver, lungs, 

listed in Table 2. A gross necropsy was performed 

chemistry parameters. The parameters measured are 

from the orbital sinus of all animals for clinical 

At the end of the 14-day studies, blood was collected 

appropriate doses to be used in the 2-year studies. 

methylphenidate hydrochloride and to determine the 

cumulative toxic effects of repeated exposure to 

The 13-week studies were conducted to evaluate the 

ISWEEK STUDIES 

average of 4 weeks old; animals were quarantined for 

(Frederick, MD). On receipt, rats and mice were an 

obtained from Frederick Cancer Research Facility 

Male and female F344/N rats and B6C3Fl mice were 

Program (Appendix.L). 

using the protocols of the NTP Sentinel Animal 

on five male and five female control rats and mice 

terminal sacrifice, serologic analyses were performed 

and gross observation for evidence of disease. At 

mice were randomly selected for parasite evaluation 

ning of the studies, five male and five female rats and 

13 days before exposure began. Prior to the beginTable 2. 

design and animal maintenance are summarized in 

studies, and at necropsy. Further details of study 

the beginning of the studies, once weekly during the 

weekly by cage. The animals were weighed prior to 

corded twice daily. Feed consumption was recorded 

group-housed animals. Clinical findings were reremainder of the study because of fighting among 

first 7 weeks of the study and individually for the 

studies. Male mice were housed five per cage for the 

mice were housed five per cage throughout the 

water were available ad fibintm. Rats and female 

2,000 ppm methylphenidate hydrochloride. Feed and 

fed diets containing 0, 125, 250, 500, 1,000, or 

Groups of 10 male and 10 female rats and mice were 

formed using the protocols outlined in Appendix H. 

length and bone density measurements were persurviving to the end of the study. Nose-to-rump 

Bone density analyses were performed on all rats 

surviving rats at 4, 8, and 13 weeks into the study. 

all rats before the beginning'of the study and on 

Nose-to-rump length measurements were taken on 

the tissues and organs routinely examined. 

all other animals were also examined. Table 2 lists 

that died during the study. The liver and kidneys of 

control and 2,OOO ppm rats and mice and on animals 

histopathologic examination was performed on 

and stained with hematoqlin and eosin. A complete 

in paraffin, sectioned to a thickness of 5 to 6 pm, 

buffered formalin, processed and trimmed, embedded 

examination were fixed and preserved in 10% neutral 

thymus were weighed. Tissues for microscopic 

brain, heart, liver, lungs, right kidney, left testis, and 

A gross necropsy was performed on all animals. The 

2-YEAR STUDIES 

fed diets containing 0, 50, 250, or 500 ppm 

hydrochloride and 70 male and 70 female mice were 

containing 0,100,500, or 1,OOO ppm methylphenidate 

Groups of 70 male and 70 female rats were fed diets 

Study Design 
Materials and Methods 23 

clinical chemistry parameters, and histopathology. 

absolute and relative organ weights, hematology and 

10 female rats and mice per group were evaluated for 

15 months of exposure, groups of up to 10 male and 

methylphenidate hydrochloride. After 9 and 

Animal Program (Appendix L). 

studies using the protocols of the NTP Sentinel 

ated at 6, 12, and 18 months and at the end of the 

five male and five female rats and mice were evalubeginning of the studies. Additionally, as many as 

Rats and mice were approximately 6 weeks old at the 

these animals were also observed grossly for disease. 

rats and mice were killed and examined for parasites; 

antined for 14 to 15 days. Five male and five female 

shipments on two consecutive days and were quarquarantined for 14 days. Mice were received in two 

were quarantined for 13 days; female rats were 

(Gilroy, CA) for use in the 2-year studies. Male rats 

obtained from Simonsen Laboratories, Inc. 

Male and female F344/N rats and B6C3Fl mice were 

Source and Specification of Animals 

provided in Appendix K. 

tion on feed composition and contaminants is 

animal maintenance are given in Table 2. Informarotated once every 2 weeks. Further details of 

every 4 weeks (Appendix J). Cages and racks were 

ad libitum. Feed consumption was measured once 

housed individually. Feed and water were available 

Rats were housed five per cage and mice were 

Animal Maintenance 

and monthly thereafter. 

weights were recorded weekly for the first 13 weeks 

findings were recorded once every 4 weeks; body 

All animals were observed twice daily. Clinical 

Clinical Examinations and Pathology 

Table 2. 

grossly visible lesions. Tissues examined are listed in 

were performed on all major tissues and samples of 

scopic examination. Histopathologic examinations 

and stained with hematoxylin and eosin for microin paraffin, sectioned to a thickness of 5 to 6 pm, 

buffered formalin, processed and trimmed, embedded 

tissues were fixed and preserved in 10% neutral 

examined for grossly visible lesions, and all major 

weighed. At necropsy, all organs and tissues were 

and mice evaluated at 9 and 15 months were 

The brain, right kidney, liver, and right testis of rats 

A gross necropsy was performed on all rats and mice. 

technique was evaluated. 

slide and tissue counts were verified, and the historecords and tables were compared for accuracy, the 

quality assessment laboratory. The individual animal 

pathology tables were evaluated by an independent 

The slides, individual animal data records, and 

for inventory, slideblock match, and wet tissue audit. 

residual wet tissues were sent to the NTP Archives 

System. The microscope slides, paraffin blocks, and 

entered into the Toxicology Data Management 

laboratory pathologist, and the pathology data were 

Microscopic evaluations were completed by the study 

guidelines of McConnell et al. (1986). 

evaluated separately or combined according to the 

data, the diagnosed lesions for each tissue type were 

(1985). For subsequent analyses of the pathology 

Maronpot and Boorman (1982) and Boorman et al. 

procedures have been described, in part, by 

pathologists and the PWG. Details of these review 

final diagnoses represent a consensus of contractor 

pathologist, the diagnosis was changed. Thus, the 

consensus differed from the opinion of the laboratory 

previously rendered diagnoses. When the PWG 

tissues without any knowledge of dose groups or 

toxicologic pathology. This group examined the 

ogist and other pathologists experienced in rodent 

The PWG consisted of the quality assessment patholwere presented by the chair to the PWG for review. 

assessment pathologist, or lesions of general interest 

in diagnoses between the laboratory and quality 

chemical administration, examples of disagreements 

slides containing examples of lesions related to 

pathologists existed. Representative histopathology 

nosis between the laboratory and quality assessment 

any other tissues for which a disagreement in diag- 

(PWG) chair, who reviewed the selected tissues and 

mitted to the NTP Pathology Working Group 

The quality assessment report and slides were subgroups for equality and Tarone’s (1975) life table test 

on survival us& Cox’s (1972) method for testing two 

Statistical analyses for possible dose-related effects 

dying from natural causes were not censored. 

were censored from the survival analyses; animals 

found dead of other than natural causes or missing 

and is presented in the form of graphs. Animals 

product-limit procedure of Kaplan and Meier (1958) 

The probability .of survival was estimated by the 

Survival Analyses 

Statistical Methods 
24 Methylphenidate Hydrochloride, NTP TR 439 

for the survival analyses are two sided. 

to identify dose-related trends. All reported P values 

Calculation of Incidence 

of the study in the absence of mortality from all 

incidence that would have been observed at the end 

i.e., the Kaplan-Meier estimate of the neoplasm 

rate for each group and each site-specific neoplasm, 

C3, and D3 also give the survival-adjusted neoplasm 

on which a necropsy was performed. Tables A3, B3, 

the denominators consist of the number of animals 

tial sites of occurrence (e.g., leukemia or lymphoma), 

evaluation, or when neoplasms had multiple potengland, and mammary gland) before microscopic 

in certain tissues (e.g., skin, intestine, harderian 

scopic examination was required to detect neoplasms 

examined microscopically. However, when macroas the numbers of animals affected at each site 

C3, and D3) and all nonneoplastic lesions are given 

the incidences of most neoplasms (Tables A3, B3, 

scopically. For calculation of statistical significance, 

number of animals with that site examined microsuch lesions at a specific anatomic site and the 

and D5 are given as the number of animals bearing 

, as presented in Tables Al, A5, B1, B5, C1, C5, Dl, 

The incidences of neoplasms or nonneoplastic lesions 

other competing risks (Kaplan and Meier, 1958). 

Crowley, 1984). 

the time-specific neoplasm incidences (McKnight and 

neoplasm prevalences also provides a comparison of 

incidental, this comparison of the time-specific 

Dinse and Haseman (1986). When neoplasms are 

Lagakos (1983), further described and illustrated by 

mortality is the prevalence analysis of Dinse and 

dose. This method of adjusting for intercurrent 

likelihood score test for the regression coefficient of 

control groups were compared on the basis of the 

enhanced. The neoplasm incidences of exposed and 

nated if the fit of the model was not significantly 

porated initially, and the quadratic term was elimiBoth linear and quadratic terms in time were incora logistic function of chemical exposure and time. 

this approach, neoplasm prevalence was modeled as 

cause and thus did not affect the risk of death. In 

covered as the result of death from an unrelated 

assumed that the diagnosed neoplasms were dismethod used was logistic regression analysis, which 

not rapidly lethal. Thus, the primary statistical 

considered to be incidental to the cause of death or 

The majority of neoplasms in these studies were 

Analysis of Neoplasm Incidences 

neoplasm-bearing animals. 

1979), procedures based on the overall proportion of 

Armitage trend test (Armitage, 1971; Gart et al., 

plasms, and the Fisher exact test and the CochranTarone, 1975), appropriate for rapidly lethal neomethods include the life table test (Cox, 1972; 

tests are summarized in the appendixes. These 

statistical analysis were used, and the results of these 

In addition to logistic regression, other methods of 

Haseman (1984). 

further discussion of these statistical methods, see 

to evaluate selected nonneoplastic lesions. For 

described in the preceding paragraphs were also used 

reported P values are one sided. The procedures 

were used in the analysis of neoplasm incidence, and 

overall dose-related trend. Continuity-corrected tests 

of each exposed group with controls and a test for an 

Tests of significance included pairwise comparisons 

affected animals, was used. 

test, a procedure based on the overall proportion of 

detected at the interim evaluation, the Fisher exact 

function of chemical exposure and time. For lesions 

plastic lesion prevalence was modeled as a logistic 

was a logistic regression analysis in which nonneonot rapidly lethal, the primary statistical analysis used 

considered to be incidental to the cause of death or 

Because all nonneoplastic lesions in this study were 

Analysis of Nonneoplastic Lesion Incidences 

the Mann-Whitney U test (Hollander and Wolfe, 

severity values were analyzed for significance using 

related trend (Dunnett’s or Dunn’s test). Average 

than a test that does not assume a monotonic dosetest) was more appropriate for pairwise comparisons 

whether a trend-sensitive test (Williams’ or Shirley’s 

icance of the dose-related trends and to determine 

(Jonckheere, 1954) was used to assess the signifShirley (1977) and Dunn (1964). Jonckheere’s test 

the nonparametric multiple comparison methods of 

typically skewed distributions, were analyzed using 

Clinical chemistry and hematology data, which have 

of Dunnett (1955) and Williams (1971, 1972). 

using the parametric multiple comparison procedures 

approximately normal distributions, were analyzed 

ables. Organ and body weight data, which have 

control groups in the analysis of continuous variicance of pairwise comparisons between exposed and 

TWO approaches were employed to assess the signifAnalysis of Continuous Variables 
Materials and Methods 25 

Williams' or Dunnett's test. 

1973). Nose-to-rump lengths were analyzed using 

effects. 

for neoplasms appearing to show compound-related 

et al., 1984, 1985) are included in the NTP reports 

from the NTP historical control database (Haseman 

certain instances. Consequently, neoplasm incidences 

the overall assessment of neoplasm incidence in 

evaluation, historical control data can be helpful in 

first and most appropriate control group used for 

Although the concurrent control group is always the 

Historical Control Data 

Report. 

addressed during the preparation of this Technical 

all comments had been resolved or were otherwise 

findings were reviewed and assessed by NTP staff, so 

the reports and are on file at NIEHS. The audit 

ed. Audit procedures and findings are presented in 

a draft of this NTP Technical Report were conductdata, pathology specimens, final pathology tables, and 

covering completeness and accuracy of the pathology 

dent quality assurance contractor. Separate audits 

studies were audited retrospectively by an indepenstudies were submitted to the NTP Archives, these 

Part 58). In addition, as records from the 2-year 

Good Laboratory Practice Regulations (21 CFR, 

compliance with Food and Drug Administration 

The 13-week and 2-year studies were conducted in 

Quality Assurance Methods 

GENETIC TOXICOLOGY 

typhimurium and chromosomal damage in cultured 

to induce mutations in various strains of Salmonella 

ide was assessed by testing the ability of the chemical 

The genetic toxicity of methylphenidate hydrochlorstudies and the results are given in Appendix E. 

Chinese hamster ovary cells. The protocols for these 

and Miller, 1977; Straus, 1981; Crawford, 1985). 

nogenesis and the somatic mutation theory (Miller 

based on the electrophilic theory of chemical carcidamage and to predict carcinogenicity in animals, 

to study mechanisms of chemically induced DNA 

These genetic toxicity tests were originally developed 

short-term in vitro and in vivo genetic toxicity tests. 

the structure and responses of the chemical in 

tion of carcinogenicity in experimental animals from 

to develop a database that would permit the evaluahydrochloride are part of a larger effort by the NTP 

The genetic toxicity studies of methylphenidate 

not yet defined. 

row chromosome aberration or micronucleus tests is 

carcinogenicity of a positive response in bone marivity of the Salmonella alone. The predictivity of 

included the Salmonella test improved the predictgenetic toxicity tests. That is, no battery of tests that 

that there is no complementarity among the in vitro 

Salmonella mutagens were rodent carcinogens), and 

test for rodent carcinogenicity (89% of the 

in Salmonella is currently the most predictive in vitro 

Data from NTP studies show that a positive response 

can be induced by the chemical being investigated. 

on the types of DNA and chromosome effects that 

although these other tests can provide information 

genicity (Tennant et al., 1987; Zeiger et al., 1990), 

tests do not correlate well with rodent carcinoand Tennant, 1991). Other in vitro genetic toxicity 

rats and mice and/or at multiple tissue sites (Ashby 

correlated with the induction of carcinogenicity in 

philicity and Salmonella mutagenicity ishighly 

cinogenicity in rodents. The combination of electroreactivity), mutagenicity in Salmonella, and carpotential electrophilicity (structural alert to DNA 

There is a strong correlation between a chemical's 
26 Methylphenidate Hydrochloride, NTP TR 439 

Experimental Design and Materials and Methods in the Feed Studies of Methylphenidate Hydrochloride 

TABLE 2 

14-Day Studies 13-Week Studies 2-Year Studies 

(Madison, WI) 

Hazleton Laboratories America, Inc. 

Study Laboratory 

Mice: B6C3Fl 

Rats: F344/N 

Strain and Species 

(Frederick, MD) 

Frederick Cancer Research Facility 

Animal Source 

Mice: 16 days 

Rats: 15 days 

Time Held Before Studies 

7 weeks 

Average Age When Studies Began 

Mice: 17 June 1983 

Rats: 16 June 1983 

Date of First Dose 

14 days 

Duration of Dosing 

Mice: 30 June 1983 

Rats: 29 June 1983 

Date of Last Dose 

(Madison, WI) 

Hazleton Laboratories America, Inc. 

Mice: B6C3F1 

Rats: F344/N 

(Frederick, MD) 

Frederick Cancer Research Facility 

13 days 

6 weeks 

11 October 1983 

Mice: 92 days 

Rats: 90 days 

Mice: 11,12 January 1984 

Rats: 9, 10 January 1984 

(Worcester, MA) 

TSI Mason Research Institute 

Mice: B6C3Fl 

Rats: F344/N 

(Gilroy, CA) 

Simonsen Laboratories, Inc. 

Mice: ,14 or 15 days 

Rats: 13 days (males) 

or 14 days (females) 

6 weeks 

Mice: 1 August 1986 

Rats: 27 August 1986 (males) 

or 28 August 1986 (females) 

105 weeks (females) 

104 weeks (males) 

3 December 1987 (females) 

1 December 1987 (males); 

15-Month interim evaluation: 

4 June 1987 (females) 

28 May 1987 (males); 

Rats: $)-Month interim evaluation: 

25 August 1988 (females) 

17 August 1988 (males); 

27 October 1987 (males); 

15-Month interim evaluation 

7 May 1987 (females) 

30 April 1987 (males); 

Mice: 9-Month interim evaluation: 

Terminal: 

. 29 October 1987 (females) 

Terminal: 

29 July 1988 (females) 

21 July 1988 (males); 
Materials and Methods 27 

(continued) 

Experimental Design and Materials and Methods in the Feed Studies of Methylphenidate Hydrochloride 

TABLE 2 

14-Day Studies 13-Week Studies 2-Year Studies 

Mice: 1 July 1983 

Rats: 30 June 1983 

Necropsy Dates 

9 weeks 

Average Age at Necropsy 

5 males and 5 females 

Size of Study Groups 

proportionately by weight class 

Animals assigned at random and 

Method of Distribution 

5 

Animals per Cage 

Mice: 11,12 January 1984 

Rats: 9,lO January 1984 

19 weeks 

10 males and 10 females 

Same as 14-day studies 

separately 

1983, when males were housed 

Mice: 5 per cage until 22 November 

Rats: 5 

Mice: metal neck tag and ear punch Mice: ear notches and toe clips 

Rats: metal ear tag Rats: metal ear tag 

Method of Animal Identification 

Rats: 9-Month interim evaluation: 

2-13 September 1988 (females) 

24-31 August 1988 (males); 

Terminal 

week of 30 November 1987 

15-Month interim evaluation: 

week of 1 June 1987 (females) 

week of 25 May 1987 (males); 

8-16 August 1988 (females) 

29 July-9 August 1988 (males); 

Terminal: 

week of 26 October 1987 

15-Month interim evaluation: 

week of 4 May 1987 (females) 

week of 27 April 1987 (males); 

Mice: 9-Month interim evaluation: 

Terminal: 111 weeks (males); 

15-Month interim evaluation: 71 weeks 

9-Month interim evaluation: 47 weeks 

112 weeks (females) 

70 males and 70 females 

random number table. 

on racks in dose columns using a third 

cages to dose groups. Cages were placed 

of random numbers was used to assign 

table of random numbers. A second table 

placed into pre-numbered cages using a 

The required number of animals were 

Mice: 1 

Rats: 5 

Mice: toe clip 

Rats: toe clip and tail tattoo 
28 Methylphenidate Hydrochloride, NTP TR 439 

TABLE 2 

. Experimental Design and Materials and Methods in the Feed Studies of Methylphenidate Hydrochloride 

(continued) 

14-Day Studies 13-Week Studies 2-Year Studies 

collection; changed twice weekly 

until 16 hours prior to serum 

Winfield, IA), available ad libitum ad libitum; changed once weekly 

ration (Teklad TestDies, ad libitum until terminal sacrifice Brothers, Inc.Gardners, PA), available 

NIH-7 open formula rat nd mouse Same as 14day studies, but available NIH-07 open formula mash (Zeigler 

Diet 

3 weeks 

Maximum Storage Time for Feed 

ad libitum 

automatic watering system, available 

Engineering (Palo Alto, CA) via 

Water supplied by Systems 

Water Distribution 

changed twice weekly 

Systems, Inc., Aberdeen, MD), 

Clear polycarbonate (Hazleton 

Cages 

weekly 

Warrensburg, NY), changed twice 

(Northeastern Products, Corp., 

Heat-treated hardwood chips 

Bedding 

Not available 

Cage Filters 

each 2 weeks 

Inc., Aberdeen, MD), changed onq 

Stainless steel (Hazleton Systems, 

Racks 

Same as 14-day studies 

Same as 14-day studies 

once weekly for males caged separately 

Same as 14-day studies, but changed 

once weekly for males caged separately 

Same as 14-day studies, but changed 

Non-woven polyester fiber 

Same as 14-day studies 

Room air: 

Fluorescent light: 12 hours/day 

Relative humidity: 50% k 20% 

Average temperature: 22.2" C 

Animal Room Environment 

minimum of 10 changeshour 

Same as 14-day studies 

Same as 14-day studies 

available ad libitum 

(Edstrom Industries, Waterford, WI), 

supply) via automatic watering system 

Tap water (City of Worcester water 

Rochelle Park, NJ), changed twice weekly 

Polycarbonate (Lab Products, Inc., 

twice weekly (rats) or weekly (mice) 

Products, Inc., Warrensburg, NY), changed 

BetaChip hardwood chips (Northeastern 

2 weeks 

Co., Cincinnati, OH), changed once each 

Non-woven polyester fiber (Snow Filtration 

2 weeks 

Rochelle Park, NJ), changed once each 

Stainless steel (Lab Products, Inc., 

Room air: minimum of 10 changeshour 

Fluorescent light: 12 hours/day 

Relative humidity: 40% to 55% 

Temperature: 19.4" C to 25" C 

feed, available ad libitum in feed, available ad libitum available ad libitum 

0, 16, 62, 250, 1,000, or 4,000 ppm in 0, 125, 250, 500, 1,000, or 2,000 ppm Rats: 0, 100, 500, or 1,000 ppm in feed, 

Doses 

available ad libitum 

Mice: 0,50, 250, or 500 ppm in feed, 
Materials and Methods 29 

(continued) 

Experimental Design and Materials and Methods in the Feed Studies of Methylphenidate Hydrochloride 

TABLE 2 

14-Day Studies 13-Week Studies 2-Year Studies 

weekly by cage. 

consumption was recorded twice 

terminal sacrifice. Feed and water 

and approximately 16 hours before 

beginning of the study, twice weekly, 

daily. Animals were weighed at the 

clinical observations recorded twice 

signs, moribundity, and death; 

Observed twice daily for clinical 

Type and Frequency of Observation 

CO, asphyxiation 

Method of Sacrifice 

were weighed. 

right testis, and thymus of all animals 

The heart, right kidney, liver, lung, 

Necropsy performed on all animals. 

Necropsy 

dehydrogenase 

aminotransferase, sorbitol 

aminotransferase, aspartate 

nitrogen, creatinine, alanine 

CIbricol chaniseyr Blood urea 

sinuses of all animals. 

Blood was collected from the orbital 

Clinical Pathology 

None 

Special Studies 

Observed twice daily for clinical signs, Observed twice daily for moribundity and 

moribundity, and death; clinical mortality; clinical observations recorded 

observations recorded twice daily. once every 4 weeks. Animals weighed at 

Animals were weighed at the beginning the beginning of the studies, once weekly 

of the study, weekly, and at the end of for the first 13 weeks, and once every 

the studies. Feed consumption was 4 weeks thereafter. Feed consumption 

recorded weekly by cage. measured once every 4 weeks. 

C02 asphyxiation 

to the end of the studies were weighed. 

testis, and thymus of animals surviving 

The heart, right kidney, liver, lung, left 

Necropsy performed on all animals. 

None 

rats at the end of the study. 

Bone density measured on all surviving 

8, and 13 weeks after study initiation. 

of the study and on surviving rats at 4, 

taken on all rats prior to the beginning 

Nose-to-rump length measurements 

CO, asphyxiation 

kidney, liver, and right testis. 

interim evaluations were brain, right 

Organs weighed at the 9- and 15-month 

Necropsy performed on all animals. 

aminotransferase. 

aminotransferase, and aspartate 

blood urea nitrogen, creatinine, alanine 

Uinicul Ckmidry: y-glutamyltransferase, 

eosinophils, and nucleated erythrocytes. 

neutrophils, lymphocytes, monocytes, 

reticulocytes, leukocytes, segmented 

erythrocyte hemoglobin concentration, 

mean erythrocyte hemoglobin, mean 

erythrocytes, mean erythrocyte volume, 

Hanardogy: hematocrit, hemoglobin, 

evaluation animals. 

sinus of all 9- and 15-month interim 

from blood collected from the retro-orbital 

The following parameters were measured 

None 
30 Methylphenidate Hydrochloride, NTP TR 439 

(continued) 

Experimental Design and Materials and Methods in the Feed Studies of Methylphenidate Hydrochloride 

TABLE 2 

14-Day Studies 13-Week Studies 2-Year Studies 

the kidneys and livers of all animals. performed on all control and 

Histopathology was performed on Complete histopathology was 

Histopathology 

microscopically. 

animals were also examined 

liver of 125,250,500, and 1,000 ppm 

bladder and uterus. The kidney and 

vesicle, thyroid gland, trachea, urinary 

testis with epididymis and seminal 

(forestomach and glandular), thymus, 

jejunum, ileum), spleen, stomach 

gland, skin, small intestine (duodenum, 

(rats only), prostate gland, salivary 

gland, pituitary gland, preputial gland 

nose, ovary, pancreas, parathyroid 

mandibular or mesenteric lymph node, 

large intestine (cecum, colon, rectum), 

kidney, liver, lung, mammary gland, 

gland (rats only), esophagus, heart, 

gland, bone and marrow, brain, clitoral 

tissues examined included: adrenal 

study. In addition to gross lesions, the 

animals that died before the end of the 

2,000 ppm rats and mice and on all 

bladder, and uterus. 

thymus, thyroid gland, trachea, urinary 

with epididymis and seminal vesicle, 

stomach (forestomach and glandular), testis 

(duodenum, jejunum, ileum), spleen, 

gland, salivary gland, skin, small intestine 

gland, preputial gland (rats only), prostate 

pancreas, parathyroid gland, pituitary 

mesenteric lymph node, nose, ovary, 

lung, mammary gland, mandibular or 

intestine (cecum, colon, rectum), liver, 

gallbladder (mice only), heart, kidney, large 

brain, clitoral gland (rats only), esophagus, 

included: adrenal gland, bone and marrow, 

and tissue masses, the tissues examined 

all animals. In addition to gross lesions 

Complete histopathology was performed on 
31 

RESULTS 

RATS 

slightly lower than that of the controls. 

mean body weight gain of 1,000 ppm males was 

significantly lower than those of the controls. The 

weight gains of 4,000 ppm males and females were 

(Table 3). Final mean body weights and mean body 

All animals survived to the end of the study 

14-DAY STUDY 

of a transient anorexic effect of methylphenidate 

These findings are consistent with literature reports 

that by controls throughout the rest of the study. 

that by controls, but was similar to or greater than 

tion by 4,000 ppm males and females was lower than 

During the first 5 days of the study, feed consump90, or 360 mg/kg per day (females). 

or 380 mgkg body weight per day (males) or 1,520, 

4,000 ppm received approximate doses of 1,5,20,!30, 

hydrochloride. Rats exposed to 16,62,25O,l,OOO, or 

study. 

appeared normal throughout the remainder of the 

methylphenidate hydrochloride; these animals 

females and in females exposed to 250 or 1,OOO ppm 

included hyperactivity in 4,OOO ppm males and 

Clinical findings during the first week of the study 

of 4,000 ppm males was greater than that of the 

those of the controls, and the relative kidney weight 

males and females were significantly greater than 

Absolute and relative liver weights of 4,OOO ppm 

of Methylphenidate Hydrochloride 

Survival, Mean Body Weights, and Feed Consumption of Rats in the 14-Day Feed Study 

TABLE 3 

Week 1 Week 2 

Concentration Survivala Initial Final Change to Controls Consumption' 

Mean Bodv WeiPhtb (g) Relative Feed 

Final Weight 

(PPm) (W 

Male 

62 

16 

0 

4,000 

1,000 

250 

Female 

62 

16 

0 

4,000 

1,000 

250 

515 

515 

515 

515 

515 

515 

515 

515 

515 

515 

515 

515 

155 f 2 216 f 4 61 f 2 

161 f 1 215 rf: 4 53 f 3 

159 f 1 216 f 4 57 f 4 

156 f 2 212 f 2 56 rf: 2 

159 f 2 211 f 3 52 f 2' 

159 f 2 196 f 4** 37 2 3** 

116 k 1 143 rf: 2 27 f 2 

119 f 1 144 f 2 25f2 

118 k 1 143 2 1 24f2 

116 f 2 136 f 3 20 f 1 

119 f 2 142 f 2 23k2 

118 f 1 131 f 3** 13 f 3** 

91 

98 

98 

100 

99 

91 

99 

95 

99 

100 

16.3 17.0 

16.0 16.4 

16.0 17.0 

15.5 16.6 

15.1 16.4 

13.6 20.4 

11.3 11.1 

11.9 10.7 

11.7 10.7 

11.1 10.1 

10.2 12.3 

8.4 14.3 

l Significantly different (PsO.05) from the control group by Williams' or Dunnett's test 

** PSO.01 a Number of animals surviving at 14 days/number initially in group 

Feed consumption is expressed as grams per animal per day. 

Weights are given as mean f standard error. 
32 

in all male exposure groups. 

Serum creatinine levels were significantly decreased 

were significantly greater than those of the controls. 

exposed groups of females except the 16 ppm group 

males exposed to 1,OOO or 4,OOO ppm and of all 

controls (Table Gl). Serum urea nitrogen levels of 

aminotransferase activity was lower than that of the 

controls except in 4,OOO ppm males where aspartate 

exposed rats were generally similar to those of the 

and aspartate aminotransferase activity lewels of 

controls (Table Fl). Serum alanine aminotransferase 

Methylphenidate Hydrochloride, NTP TR 439 

of methylphenidate hydrochloride or in controls. 

observed in animals exposed to lower concentrations 

4,OOO ppm females. These changes were not 

observed in four 4,OOO ppm males and in all five 

Centrilobular hepatocellular hypertrophy was 

There were no treatment-related gross lesions. 

13-week study was 2,OOO ppm. 

the 14-day study, the high dose selected for the 

effects observed in 4,OOO ppm males and females in 

Because of the lower mean body weights and liver 
Results 33 

13-wEEK STUDY these clinical findings were not conducted during this 

less than that by controls; there were no other 

the study, feed consumption by 2,000 ppm rats was 

than those of the controls. During the first week of 

females exposed to 250 ppm were significantly lower 

females exposed to 500, 1,000, or 2,OOO ppm and of 

controls. Mean body weight gains of males and 

males and females were similar to those of the 

(Table 4). Final mean body weights of exposed 

considered related to chemical administration 

one 250 ppm male died; these deaths were not 

One male and three females exposed to 125 ppm and 

or 9, 18, 30, 70, or 150 mgkg per day (females). 

doses of 7, 15, 30, 70, or 130 mgkg per day (males) 

250, 500, 1,000, or 2,000 ppm received approximate 

control and exposed groups. Rats exposed to 125, 

. consistent differences in feed consumption between 

study. 

cal-related histopathologic lesions were observed. 

were greater than those of the controls. No chemiabsolute and relative brain weights of 500 ppm malesAbsolute brain weight of 1,000 ppm males and 

female rats were greater than those of the controls. 

brain weights of 1,OOO and 2,OOO ppm male and 

1,000 ppm rats (Table E). Relative kidney and 

those of the controls, as were relative liver weights of 

female 2,OOO ppm rats were significantly greater than 

Absolute and relative liver weights of male and 

initiation and at 4, 8, and 13 weeks into the study 

nose-to-rump lengths measured prior to study 

No statistically significant differences were noted in 

behavior in rats, but systematic measurements for studies was 1,OOO ppm. 

locomotive activity and to enhance stereotypical and female rats, the high dose selected for the 2-year 

other similar drugs have been shown to increase absolute and relative liver weights in 2,000 ppm male 

were not reported in males. Methylphenidate and body weight gains and the significant increase in 

during weeks 9 through 13. These clinical findings Dose selection rationale: Because of the lower mean 

of the study, and 2,OOO ppm females were hyperactive 
34 Methylphenidate Hydrochloride, NTP TR 439 

of Methylphenidate Hydrochloride 

Survival, Mean Body Weights, and Feed Consumption of Rats in the 13-Week Feed Study 

TABLE 4 

Week 1 Week 13 

Concentration Survivals Initial Final Change to Controls Consumption' 

Mean Body Weightb bb Relative Feed 

Final Weight 

(PPm) (94 

Male 

500 

250 

125 

0 

2,000 

1,OoO 

Female 

500 

250 

125 

0 

2,000 

1 ,ooo 

1ono 

lono 

lono 

lono 

9noe 

9n0* 

lono 

lono 

lono 

lono 

7noe 

ion0 

133 f 2 

130+3 

136f2 

132 2 4 

131 f 3 

131 f 3 

102 2 1 

103 f 2 

104 f 2 

100 f 1 

99+2 

102 2 1 

36627 23625 

361 2 8 229 f 6 

367 f 9 233 f 7 

348*7 212 f 6* 

351 f 6 221 f 5* 

347 f 6 214 f 5** 

215 k 4 114 f 3 

m*2 106+2 

m+4 104 f 3, 

20923 105 f 3. 

204 f 4 101 + 4.. 

207 f 3 104 f 3.. 

95 

96 

95 

100 

98 

96 

95 

97 

'95 

95 

12.6 17.7f 

13.1 

13.6 17.6 

14.1 17.1 

14.1 16.5 

13.6 18.2 

20.9f 

10.5 12.0 

10.3 11.5 

10.2 11.2 

9.4f 12.1 

9.2f 12.2 

9.gf 14.2 

tt 

t 

C 

b 

a 

f 

e 

d 

Bedding in feed jars 

Week of death All died during week 9 (deaths attributed to anesthetic administered during bleeding) 

Week of death 5 (death attributed to anesthetic administered during interim bleeding for studies not reported here) 

Feed consumption is expressed as grams per animal per day. 

Weights and weight changes are given as mean f standard error. 

Number of animals surviving/number initially in group 

PSO.01 

Significantly different (PSO.05) from the control group by Williams' or Dunnett's test 
Results 35 

exposed rats was similar to that of the controls. 

Kaplan-Meier survival curves (Figure 2). Survival of 

in feed for 2 years are presented in Table 5 and in 

female rats receiving methylphenidate hydrochloride 

Estimates of survival probabilities for male and 

Survival 

2-YEAR STUDY 

Tables 6 and 7). Mean body weights of males 

similar until week 30 of the study (Figure 3 and 

Mean body weights of exposed and control rats were 

Consumption, and Clinical Findings 

Body Weights, Feed and Compound 

kilogram body weight per day for males and females. 

5,25, and 50 mg methylphenidate hydrochloride per 

of 100, 500, or 1,OOO ppm were estimated to deliver 

that by the controls (Tables J1 and J2). Exposures 

Feed consumption by exposed animals was similar to 

females were 96%, 89%, and 78% of the controls. 

control values. Final mean body weights of exposed 

500, or 1,OOO ppm were 102%, 95%, and 90% of 

Final mean body weights of males exposed to 100, 

of controls from week 30 to the end of the study. 

500 or 1,OOO ppm were 4% to 24% lower than that 

the study. Mean body weights of females exposed to 

than those of controls from week 30 to the end of 

exposed to 500 or 1,OOO ppm were 3% to 10% lower 

Survival of Rats in the 2-Year Feed Study of Methylphenidate Hydrochloride 

TABLE 5 

100 ppm 500 ppm 1,OOO .ppm 

9-Month interim evaluationa 

Animals initially in study 

Male 

Mean survival (days)C 

Percent probability of survival at end of studyb 

Animals surviving to study termination 

Natural deaths 

Moribund 

Accidental deathsa 

15-Month interim evaluationa 

Survival anawisd 

9-Month interim evaluationa 

Animals initially in study 

Female 

Mean survival (days)c 

Percent probability of survival at end of studyb 

Animals surviving to study termination 

Natural deaths 

Moribund 

15-Month interim evaluationa 

Survival analysisd 

10 

10 

70 

57 

28 

8 

14 

P=0.529N 

587 

70 

63 

31f 

6 

13 

10 

10 

P=0.096N 

601 

70 

68 

33 

7 

9 

1 

10 

10 

P=0.344N 

585 

70 

12 

10 

10 

611 

64 

32f 

6 

P=0.818N 

10 

10 

70 

69 

34 

9 

7 

P=0.257N 

598 

70 

10 

10 

10 

603 

73 

36 

4 

P=0.426N 

10 

9 

70 

34e 

8 

9 

P=0.426N 

582 

. 69 

70 

79 

39e 

4 

7 

10 

10 

P=0.154N 

610 

Includes two animals that died during the last week of the study 

Includes one animal that died during the last week of the study 

is indicated by N. 

comparisons (Cox, 1972) with the controls are in the exposed columns. A negative trend or lower mortality in an exposure group 

The result of the life table trend test (Tarone, 1975) is in the control column, and the results of the life table pairwise 

Mean of all deaths (uncensored, censored, and terminal sacrifice) 

Kaplan-Meier determinations based on the number of animals alive on the first day of terminal sacrifice 

Censored from survival analyses 
36 Methylphenidate Hy”e, NTP TR 439 

1.0 

-1 

0.9 

s 

5 

I> 

(I: 

c 

>- 

0 

LL 

a 

m 

I, 

0.8 

0.7 

:: 

0.6 

0.s 

1.0 

0.9 -1 

s 

5 

0 

I& 

3 

v, 0.8 

(I: 

z 

m 

z 

0 

a 0.7 

A 

Q 

(L 

0.6 

0.5 

........................ , ....... 

- 

- 

...... 

..... 

_,._. 

0 100 PPY 

rn OPPY 

.... 

...................... -+ 1 

C 

............. , .............. 

- 

... 

hB 

.. 

.... 

.............. ; ............... A. ............ 

.............. .... 

.i ... 

5~PP~ , I i I3 1000 PPY 

I I I I I , 15 so 45 60 79 90 105 

WEEKS ON STUDY 

1 

I I I 

15 30 45 60 75 90 105 

WEEKS ON STUDY 

0 

nCURE 2 

Methylphenidate Hydrochloride in Feed for 2 Years 

Kaplan-Meier Survival Curves for Male and Female Rats Administered 
37 

450 

400 

350 

(3 

& 

a 

z 300 

Gj 250 (3 

I 

ta 

> 

3 

2 200 

-l 

z 

150 

100 

so 

.............. .... ................ .............. ............... i.. .............. 

.............. ................ ................. ............... ................. , .............................. 

p; 

I ............. i................ '. .............. :...... .................... ... 

0 1000 PPY 

A SOOPPU 

0 I00 PPU 

rn OPPU 

........... : .......... .; ....... _..... . p.. 

I I 

15 30 45 60 75 90 105 

WEEKS ON STUDY 

................ ............. .............. ........... ............. ................. ............... ................ 

FIGURE 3 

Methylphenidate Hydrochloride in Feed for 2 Years 

Growth Curves for Male and Female Rats Administered 
38 Methylphenidate Hydrochloride, NTP TR 439 

of Methylphenidate Hydrochloride 

Mean Body Weights and Survival of Male Rats in the 2-Year Feed Study 

TABLE 6 

Study (9) Survivors (g) controls) Survivors (9) controls) Survivors (9) controls) Survivors 

on Av. Wt No. of Av. Wt Wt (%of No. of Av. Wt Wt (%of No. of Av. Wt Wt (%of No. of 

WNkS 0 ppm 100 ppm - 500 ppm 1,000 ppm 

9 

8 

7 

6 

5 

4 

3 

2 

1 

89 

85 

81 

77 

73 

69a 

65 

62 

56 

53 

49 

45 

41a 

37 

33 

29 

25 

21 

16 

13 

12 

11 

10 

104 

101 

97 

93 

391 

400 

410 

414 

425 

426 

423 

427 

431 

424 

420 

421 

415 

419 

405 

407 

396 

399 

391 

387 

372 

362 

336 

318 

314 

299 

284 

271 

254 

246 

230 

215 

199 

176 

150 

118 

Mean for weeks 

1-13 236 

14-52 384 

53-104 418 

28 

30 

35 

37 

41 

43 

44 

46 

47 

47 

58 

58 

58 

59 

59 

59 

60 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

400 

411 

417 

423 

432 

429 

427 

430 

441 

433 

430 

428 

423 

425 

412 

413 

403 

407 

397 

389 

370 

362 

337 

321 

315 

301 

284 

273 

254 

248 

232 

220 

202 

179 

150 

118 

425 

388 

238 

100 

100 

101 

100 

101 

100 

101 

100 

101 

101 

102 

102 

102 

100 

99 

102 

103 

102 

102 

102 

101 

101 

101 

102 

102 

102 

102 

102 

101 

102 

101 

102 

102 

102 

101 

99 

102 

101 

101 

34 

36 

38 

40 

42 

44 

44 

46 

46 

46 

56 

57 

58 

58 

58 

59 

59 

69 

69 

69 

69 

69 

69 

69 

69 

69 

69 

69 

69 

70 

70 

70 

70 

70 

70 

70 

372 

378 

389 

393 

398 

404 

395 

397 

398 

393 

395 

395 

385 

394 

379 

384 

381 

380 

380 

374 

362 

358 

332 

320 

314 

300 

282 

274 

256 

249 

228 

211 

199 

175 

147 

118 

392 

370 

236 

95 

95 

95 

95 

94 

95 

94 

93 

93 

93 

94 

94 

93 

94 

94 

94 

96 

95 

97 

97 

97 

99 

99 

101 

100 

100 

99 

101 

101 

101 

99 

98 

100 

100 

98 

100 

94 

96 

100 

35 

36 

42 

42 

45 

45 

46 

47 

47 

47 

57 

57 

58 

59 

59 

60 

60 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

353 

364 

367 

373 

384 

385 

393 

388 

397 

391 

389 

391 

387 

388 

376 

382 

379 

380 

373 

366 

352 

348 

323 

312 

310 

297 

281 

269 

250 

245 

228 

21 1 

197 

176 

145 

117 

382 

364 

234 

90 

91 

90 

90 

90 

90 

93 

91 

92 

92 

93 

93 

93 

93 

93 

94 

96 

95 

96 

95 

95 

96 

96 

98 

99 

99 

99 

99 

99 

99 

99 

98 

99 

100 

96 

99 

91 

95 

99 

34 

35 

40 

40 

42 

44 

44 

44 

45 

45 

55 

56 

56 

57 

58 

58 

58 

67 

67 

67 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

a Interim evaluations occurred during weeks 40 and 66. 
Results 39 

of Methylphenidate Hydrochloride 

Mean Body Weights and Survival of Female Rats in the 2-Year Feed Study 

TABLE 7 

Study (SI Survivors (8) controls) Survivors (g) controls) Survivors (9) controls) Survivors 

on Av. Wt. No. of Av. Wt. Wi. (% of No. of Av. Wt. Wt. (% of No. of Av. Wt. Wt. (% of No. of 

Weeks 0 ppm 100 ppm 500 ppm 1,000 ppm 

9 

8 

7 

6 

5 

4 

3 

2 

1 

102 

98 

94 

90 

86 

82 

78 

74 

69 

62 

58 

54 

50 

46 

42= 

39 

34 

30 

26 

22 

17 

13 

12 

11 

10 

315 

326 

31 4 

325 

326 

324 

312 

308 

297 

281 

271 

265 

256 

252 

244 

238 

233 

225 

215 

21 1 

207 

197 

195 

188 

184 

176 

171 

167 

156 

151 

141 

132 

122 

103 

Mean for weeks 

53-102 305 

14-52 

1-13 

231 

160 

33 

35 

41 

44 

45 

46 

48 

48 

48 

59 

59 

59 

59 

59 

59 

69 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

301 

310 

314 

320 

316 

313 

305 

298 

286 

271 

256 

257 

246 

240 

234 

230 

226 

221 

210 

206 

203 

193 

191 

186 

178 

173 

168 

162 

150 

147 

138 

130 

121 

103 

296 

224 

157 

98 

97 

96 

98 

97 

96 

97 

94 

97 

96 

95 

96 

97 

97 

98 

98 

98 

98 

98 

98 

99 

97 

98 

99 

97 

96 

97 

98 

99 

99 

101 

96 

95 

100 

97 

97 

98 

38 

42 

44 

45 

46 

47 

47 

47 

49 

60 

60 

60 

60 

60 

60 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

280 

290 

290 

293 

288 

282 

273 

266 

257 

243 

237 

235 

230 

222 

227 

221 

218 

21 5 

207 

204 

202 

192 

189 

185 

177 

173 

168 

162 

154 

144 

134 

126 

117 

101 

270 

216 

156 

89 

89 

92 

90 

89 

87 

87 

86 

87 

87 

87 

89 

90 

88 

93 

93 

94 

96 

96 

97 

97 

98 

97 

98 

97 

98 

98 

98 

98 

96 

96 

96 

96 

98 

89 

94 

98 

38 

39 

41 

43 

43 

44 

46 

47 

47 

58 

59 

59 

59 

59 

60 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

247 

251 

251 

252 

253 

247 

241 

240 

230 

222 

218 

218 

215 

210 

214 

214 

208 

204 

202 

198 

195 

188 

184 

179 

170 

167 

159 

152 

143 

140 

132 

124 

114 

99 

239 

207 

150 

78 

77 

80 

78 

78 

76 

77 

78 

77 

79 

80 

82 

84 

83 

88 

90 

89 

91 

94 

94 

94 

95 

94 

95 

93 

95 

93 

91 

92 

93 

94 

94 

93 

96 

78 

90 

94 

40 

40 

43 

44 

45 

46 

47 

48 

48 

59 

60 

60 

60 

60 

60 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

~ ~ ~ ~~ 

a Interim evaluations occurred during weeks 40 and 66. 
40 Methylphenidate Hydrochloride, NTP TR 439 

(Tables F3 and F4). 

was the relative brain weight of 500 ppm females 

females were greater than those of the controls, as 

Absolute and relative brain weights of 1,OOO ppm 

housed 1,000 ppm males. 

increased incidence in fighting among the groupThe only treatment-related clinical finding was an 

males and females. 

increases were statistically significant in 1,000 ppm 

and females at the 9-month interim evaluation; the 

Iymphocyte counts were generaIIy increased in maIes 

the controls (Tables G2 and G3). Leukocyte and 

exposed females were generally similar to those of 

males. Serum alanine aminotransferase levels in 

15 months were decreased in all exposed groups of 

decreased in 500 and 1,000 ppm males and at 

alanine aminotransferase activity were slightly 

At the 9-month interim evaluation, levels of serum 

Hematology and Clinical Chemistry 

for male rats and Appendix B for female rats. 

tioned in this section are presented in Appendix A 

and historical incidences for the neoplasms mendence of at least 5% in at least one animal group, 

of primary neoplasms that occurred with an inciindividual animal tumor diagnoses, statistical analyses 

incidences of neoplasms and nonneoplastic lesions, 

gland and mammary gland. Summaries of the 

neoplasms and nonneoplastic lesions in the adrenal 

biologically noteworthy changes in the incidences of 

This section describes the statistically significant or 

Pathology and Statktical Evaluation 

exposed males was similar to that of the controls. 

The incidence of adrenal medulla hyperplasia in 

below the range in historical controls (Table A4). 

and the incidence in 500 ppm maIes was slightly 

lower than that in the controls (Tables 8 and A3), 

in exposed groups of male rats were significantly 

and malignant adrenal medulla pheochromocytomas 

Adrenal Gland: The combined incidences of benign 
Results 41 

in the 2-Year Feed Study of Methylphenidate Hydrochloride 

Incidences of Neoplasms and Nonneoplastic Lesions of the Adrenal Gland of Male Rats 

TABLE 8 

Malignant Pheochromocytoma 

Benign Pheochromocytoma 

Hyperplasiab 

Adrenal Medullaa 

9-Month Interim Evaluation 

0 

10 

0 

10 

0 

10 

0 

9 

0 

0 

0 

0 

0 

0 

0 

0 

Hyperplasia 

Adrenal Medulla 

15-Month Interim Evaluation 

0 

10 

0 

10 

1 

10 

0 

10 

Malignant Pheochromocytoma 

Benign Pheochromocytoma. 

Adrenal Medulla 

2-Year Study 

Benign Pheochromocytoma 

Hyperplasia 

Logistic regression testsf 

First incidence (days) 

Terminal rate@ 

Adjusted ratesd 

Overall ratesc 

0 

0 

0 

0 

0 

0 

0 

1 

16 

49 

12 

48 

16 

49 

22 

50 

P=0.151N 

639 

50.8% 

17/49 (35%) 

12/28 (43%) 

P=0.005N 

676 

5j32 (16%) 

17.9% 

6/48 (13%) 

4/34 (12%) 

5/49 (10%) 

P=O.OOlN 

653 

13.8% 

1Oi33 (30%) 

30.3% 

10/50 (20%) 

P=0.049N 

729 (T) 

Malignant Pheochromocytoma 

Logistic regression tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

Benign or Malignant Pheochromocytomah 

Logistic regression tests 

First incidence (days) 

Terminal rates 

Adjusted rat= 

Overall rates 

3.6% 

1/49 (2%) 

729 Q 

1/28 (4%) 

P=0.273N 

3.1% 

1/48 (2%) 

729 (3 

1/32 (3%) 

P=0.732N 

1/34 (3%) 

2.9% 

1/49 (2%) 

P=0.718N 

729 (T) P=0.467N 

4 

OB3 (0%) 

0.0% 

0/50 (0%) 

P=0.087N 

639 

13/28 (46%) 

53.9% 

18/49 (37%) 

P=0.006N 

676 

6/32 (19%) 

20.9% 

7/48 (15%) 

4/34 (12%) 

5/49 (10%) 

P<0.001N 

653 

13.8% 

lot33 (30%) 

30.3% 

10/50 (20%) 

P=0.029N 

729 (3 

a Number of animals with organ examined microscopically 

(T)Terminal sacrifice 

Kaplan-Meier estimated neoplasm incidence at the end of the study after adjustment for intercurrent mortality 

Number of animals with neoplasm per number of animals with organ examined microscopically 

Number of animals with lesion 

indicated by N. 

neoplasms in animals dying prior to terminal kill as nonfatal. A negative trend or a lower incidence in an exposure group is 

P values corresponding to paimise comparisons between the controls and that exposed group. The logistic regression test regards 

Beneath the control incidence are the P values associated with the trend test. Beneath the exposed group incidence are the 

(36.1% +. 11.0%); range 14%-63% 

Historical incidence for 2-year feed studies with untreated control groups (mean k standard deviation): 445/1,234 

e Observed incidence at terminal kill 

g Not applicable; no neoplasms in animal group , 
42 Methylphenidate Hydrochloride, NTP TR 439 

is 484/1,251 (39%) with a range of 8% to 58% 

fibroadenomas of the mammary gland in female rats and lactation in exposed females (Tables 9 and B5). 

control incidence in recent NTP feed studies for there were decreases in the incidences of galactoceles 

than in controls (Tables 9 and B3). The historical in the current historical database. Additionally, 

500 and 1,OOO ppm groups were significantly lower less than the incidences in all but one of 25 studies 

significant negative trend and the incidences in the 12% and lo%, respectively, and these incidences are 

mammary gland fibroadenomas occurred with a fibroadenomas in 500 and 1,OOO ppm females were 

Mummaly Gland: In female rats, the incidence of (Table B4). The incidences of mammary gland 

in the 2-Year Feed Study of Methylphenidate Hydrochloride 

Incidences of Neoplasms and Nonneoplastic Lesions of the Mammary Gland of Female Rats 

TABLE 9 

Dose (PPm) 0 100 500 1,000 

9-Month Interim Evaluation 

Galactocele 

Lactationb 

Mammary Glanda 

Fibroadenoma 

0 

0 

10 

0 

0 

0 

9 

0 

0 

0 

8 

0 

0 

10 

0 0 

15-Month Interim Evaluation 

Galactocele 

Lactation 

Mammary Gland 

Fibroadenoma 

0 

0 

10 

0 

0 

10 

0 

0 

10 

0 

0 

10 

0 0 0 0 

2-Year Study 

Galactocele 

Lactation 

Mammary Gland 

Fibroadenomac 

10 

35 

49 

6 

36 

50 

27 

48 

1** 

25** 

50 

2* * 

Logistic regression test& 

First incidence (days) 

Terminal ratesf 

Adjusted ratese 

Overall ratesd 

P=O.002N P=0.280N P=0.014N P=0.008N 

680 720 638 559 

13/31 (42%) 5/36 (14%) 3/39 (8%) 

45.3% 38.0% 15.9% 11.7% 

15/49 (30%) 13/50 (26%) 6/48 (12%)5/50 (10%) 

11/32 (34%) 

indicated by N. 

neoplasms in animals dying prior to terminal kill as nonfatal. A negative trend or a lower incidence in an exposure group is 

P values corresponding to pairwise comparisons between the controls and that exposed group. The logistic regression test regards 

Beneath the control incidence are the P values associated with the trend test. Beneath the scposed group incidence are the 

Observed incidence at terminal kill 

Kaplan-Meier estimated neoplasm incidence at the end of the study after adjustment for intercurrent mortality 

(0 and 500 ppm groups) 

Number of animals with neoplasm per number of animals necropsied (100 and 1,OOO ppm groups) or examined microscopically 

(38.7% f 13.5%); range 8%-58% 

Historical incidence for 2-year feed studies with untreated control groups (mean f standard deviation): 484/1,251 

Number of animals with lesion 

Number of animals with organ examined microscopically 

Significantly different (PsO.01) from the control group by the logistic regression test 
Results 43 

MICE 

but not in other exposed groups of mice. 

second week of the study in some 4,OOO ppm males, 

(females). Hyperactivity was observed during the 

day (males) or 2, 10, 40, 140, or 410 mg/kg per day 

methylphenidate hydrochloridekg body weight per 

approximate doses of 2, 10, 40, 120, or 460 mg 

exposed to 16, 62, 250, 1,000, or 4,000 ppm received 

controls during the first week of the study. Mice 

4,000 ppm males and females was less than that by 

of the controls. Feed consumption by 1,000 and 

males and females were significantly less than those 

mean body weight gains of 1,000 and 4,000 ppm 

significantly less than that of the controls and the 

final mean body weight of 4,000 ppm females was 

survived until the end of the study (Table 10). The 

the study, one on the last day. All other mice 

Three 4,000 ppm males died during the last week of 

14-DAY STUDY 

significantly greater than those of the controls 

groups of males and of 4,000 ppm females were 

Absolute and relative liver weights of all exposed 

TABLE 10 

organ systems (Table G4). 

findings to indicate damage to the liver or other 

controls. There were no significant clinical chemistry 

4,000 ppm females were less than those of the 

(Table F5). Absolute and relative thymus weights of 

of the study. 

necrosis were not found in mice that lived to the end 

the study. However, renal tubule degeneration and 

of two 4,000 ppm males that died before the end of 

degeneration and necrosis were found in the kidneys 

and liver. Slight, multifocal tubule epithelial cell 

Chemical-related lesions were found in the kidney 

more severe in males than in females. 

severity was dose related and the hypertrophy was 

and in males exposed to 250 ppm. In general, the 

observed in all mice exposed to 1,OOO or 4,000 ppm 

Centrilobular hepatocellular hypertrophy was 

13-week study. 

2,000 ppm was the high dose selected for the 

Because of decreased survival in 4,000 ppm males, 

of Methylphenidate Hydrochloride 

Survival, Mean Body Weights, and Feed Consumption of Mice in the 14-Day Feed Study 

Week 1 Week 2 

Concentration Sumvala Initial Final Change to Controls Consumption' 

Mean Body Weightb (9) Relative Feed 

Final Weight 

(PPm) (%I 

Male 

62 

16 

0 

4,000 

1,000 

250 

515 20.5 f 0.5 24.1 f 0.5 3.6 f 0.2 

515 22.1 f 0.6 25.2 f 0.9 3.1 f 0.3 104 

515 22.0 f 0.5 24.6 -c 0.5 2.6 f 0.0 102 

515 20.2 f 0.4 23.7 f 0.4 3.6 f 0.3 98 

515 20.7 f 0.4 22.9 f 0.5 2.2 f 0.3*; 95 

219 22.2 f 0.5 22.7 f 1.5 0.6 f 0.6;' 94 

3.3 3.3 

3.2 3.7 

3.0 3.9 

2.9 4.4 

2.4 2.7 

2.0 3.2 

Female 

62 

16 

0 

4,000 

1 

250 

515 16.3 f 0.4 19.4 f 0.2 3.1 f 0.3 

5-15 16.1 k 0.3 19.2 f 0.5 3.1 f 0.2 99 

515 16.8 2 0.3 18.9 f 0.4 2.1 k 0.3 97 

515 15.9 k 0.3 19.4 f 0.5 3.5 f 0.4 100 

515 16.7 f 0.2 18.7 f 0.3 2.0.2 0.3; 96 

515 16.5 f 0.2 17.3 f 0.2;' 0.9 f 0.2** 89 

2.0 2.4 

1.9 3.3 

2.0 3.2 

1.9 3.6 

1.6 3.2 

1.4 2.1 

* Significantly different (PSO.05) from the control group by Williams' or Dunnett's test ** PSO.01 a Number of animals surviving at 14 dayslnumber initially in group 

Day of death 11,11,14 

Feed consumption is expressed as grams per animal per day. 

Weights are given as mean f standard error. 
44 Methylphenidate Hydrochloride, NTP TR 439 

reduced body weight gains were observed in females 

2,000 ppm females was 87% that of the controls, and 

81% of the controls. The final mean body weight of 

The final mean body weight of 2,000 ppm males was 

was 90%, 87%, or 88% of the controls, respectively. 

weight of males exposed to 250, 500, or 1,000 ppm 

lower mean body weight gains. The final mean body 

of the controls; all exposed groups had significantly 

125 ppm males, were significantly lower than those 

exposed groups of males, with the exception of 

study (Table 11). Final mean body weights of all 

The remaining animals survived to the end of the 

attributed to fighting among group-housed males. 

before the end of the study, but the deaths were 

One control male and one 1,000 ppm male died 

ISWEEK STUDY 

hydrochloride. 

exposed to 250 ppm or greater methylphenidate 

260 mag per day (females). 

body weight per day (males) or 15, 30, 70, 125, or 

receive approximately 15, 30, 70, 115, or 230 mgkg 

methylphenidate hydrochloride were estimated to 

Mice exposed to 125, 250, 500, l,OOO, or 2,000 ppm 

cases, the absolute organ weight was not increased. 

attributed to decreases in body weights; in most 

Other increases in relative organ weights were 

male mice in lower exposure groups (Table F6). 

of the controls, as were the relative liver weights of 

2,000 ppm mice were significantly greater than those 

The absolute and relative liver weights of 1,OOO and 

of Methylphenidate Hydrochloride 

Survival, Mean Body Weights, and Feed Consumption of Mice in the 13-Week Feed Study 

TABLE 11 

(W Week Id Week 13 

Concentration Survivala Initial Final Change to Controls Consumption' 

Mean Body Weightb (E) Relative Feed 

Final Weight 

(PPm) 

Male 

500 1ono 22.5 f 0.6 31.1 f l.l** 8.6 & 1.0** 87 

250 10/10 22.8 f 0.4 32.4 f 1.1** 9.6 -c 1.1" 90 

125 1ono 23.1 f 0.2 33.6 f 0.5 10.5 -c 0.4* 94 

0 22.8 f 0.4 35.9& 0.5 13.2 -c 0.6 

1,000 9/10f 23.5 f 0.3 31.7 f 0.5** 8.2 f 0.5*' 88 

2,000 1ono 22.9 f 0.3 28.9 f 0.7** 6.0 f 0.7** 81 

9/10e 2.9 4.1 

3.0 3.7 

3.1 3.7 

3.7 3.7 

2.7 3.6 

2.2 3.7 

Female 

0 10/10 17.4 f 0.3 28.5 f 1.5 11.2 f 1.3 

125 loll0 17.7 ? 0.3 27.1 2 0.5 9.4 ? 0.5 95 

250 1 O/l 0 17.4 f 0.3 26.6 f 0.7 9.2 f 0.6: 93 

500 loll0 17.6 f 0.2 26.6 f 0.6 9.0 f 0.4. 93 

1,Ooo lono 17.7 f 0.2 26.6 f 0.6 8.9 & OS* 93 

2,000 10/10 17.3 f 0.2 24.8 f 0.3** 7.5 f 0.2:. 87 

4.3 2.7 

2.7 2.5 

3.1 2.6 

3.6 2.7 

2.9 2.7 

2.7 2.8 

.I 

. 

C 

b 

a 

f 

e 

d 

Week of death: 6 (death was attributed to fighting) 

Week of death 3 (death was attributed to fighting) 

Due to feed spillage during week one, mouse jars were placed inside rat jars for the remainder of the study. 

Feed consumption is expressed as grams per animal per day. 

Weights and weight changes are given as mean f standard error. 

Number of animals surviving/number initially in group 

PSO.01 

Significantly different (PSO.05) from the control group by Williams' or Dunnett's test 
Results 45 

observed in females. 

not. Similar histopathologic lesions were not 

seen in 250 and 125 ppm males, but hypertrophy was 

(Table 12). Degeneration and minimal necrosis were 

males exposed to 500, 1,000, or 2,000 ppm 

necrosis of individual hepatocytes were observed in 

Centrilobular hypertrophy and degeneration or 

for the 2-year mouse study. 

13-week study, a high dose of 500 ppm was selected 

observed in 1,000 and 2,000 ppm male mice in the 

body weights in males and females and liver lesions 

Dose selection rationale: Because of lower final mean 

of Methylphenidate Hydrochloride 

Incidences of Nonneoplastic Lesions of the Liver of Male Mice in the 13-Week Feed Study 

TABLE 12 

Dose (PPW 0 125 250 500 1,000 2,000 

Livera 

Necrosis 

Degeneration 

Centrilobular hypertrophyb 0 

9 

0 

10 

0 

10 10 9 10 

1 (1.0)' 8** (1.1) lo*' (2.0) 

0 

1 (1.0) 

1 (1.0) 1 (2.0) 7** (1.1) 7** (1.1) 7*' (2.0) 

1 (1.0) 0 2 (1.0) 1 (1.0) 7** (1.7) 

a Number of animals with liver examined microscopically 

** Significantly different (PSO.01) from the control group by the Fisher mct test. 

Average seventy grade of lesions in affected animals (l=minimal; 2=mild; 3=moderate; 4=marked) 

Number of animals with lesion 
46 Methylphenidate Hydrochloride, NTP TR 439 

similar to that of the controls. 

all exposed groups of male and female mice was 

Kaplan-Meier survival curves (Figure 4). Survival of 

in feed for 2 years are presented in Table 13 and in 

female mice receiving methylphenidate hydrochloride 

Estimates of survival probabilities for male and 

Survival 

2-y~ STUDY 

than those of the controls (Figure 5 and Tables 14 

weights of 250 ppm females were 3% to 7% lower 

11% lower than those of the controls and mean body 

250 and 500 ppm males were approximately 3% to 

Throughout much of the study, mean body weights of 

Consumption, and. Clinical Findings 

Body Weights, Feed and Compound were no chemical-related clinical findings. 

per kilogram body weight per day for females. There 

body weight per day for males and 8,40, and 80 mg 

60 mg methylphenidate hydrochloride per kilogram 

and 500 ppm were estimated to provide 6, 30, and 

controls (Tables J3 and J4). Exposures of 50, 250, 

consumption by exposed mice was similar to that by 

93%, or 97% (females) that of the controls. Feed 

chloride were 97%, 89%, or 93% (males) and 98%, 

to SO, 250, or 500 ppm methylphenidate hydroand 15). Final mean body weights of mice exposed 

G6). 

or 15-month interim evaluations (Tables G5 and 

hematology or clinical chemistry parameters at the 9- 

There were no biologically significant differences in 

Hematology and Clinical Chemistry 
Results 47 

Survival of Mice in the 2-Year Feed Study of Methylphenidate Hydrochloride 

TABLE 13 

0 PPm 50 PPm 250 ppm 500 ppm 

Male 

Animals initially in study 70 70 70 70 

Mean survival (days)c 

Percent probability of survival at end of studyb 

Animals surviving to study termination 

Natural deaths 

Moribund 

15-Month interim evaluationa 

9-Month interim evaluationa 

Survival analysisd 

618 

90 

45 

3 

2 

10 

10 

623 

90 

45 

3 

2 

10 

10 

615 

88 

44e 

2 

4 

10 

10 

616 

82 

41 

5 

4 

10 

10 

P=O.219 P=1.000N P=O.967 P=O.414 

Female 

Animals initially in study 

Mean survival' (days)c 

Percent probability of survival at end of studyb 

Animals suIviving to study termination 

Natural deaths 

Moribund 

Missinga 

Accidental deathsa 

15-Month interim evaluationa 

9-Month interim evaluationa 

Sulvival analysisd 

69 69 70 70 

1 

10 

10 

10 

9 

10 

10 

10 

10 

7 

7 

1 

582 

73 

35e 

78 

37e 

5 

6 

604 

75 88 

37 44 

6 

7 6 

603 627 

P=O.l02N P=O.597 P=O.888 P=0.235N 

a Censored from survival analyses 

is indicated by N. 

comparisons (Cox, 1972) with the controls are in the exposed columns. A negative trend or lower mortality in an exposure group 

The result of the life table trend test (Tarone, 1975) is in the control column, and the results of the life table pairwise 

Mean of all deaths (uncensored, censored, and terminal sacrifice) 

Kaplan-Meier determinations based on the number of animals alive on the first day of terminal sacrifice 

e Includes one animal that died during the last week of the study 
- 

1.011 

-J 

2 

ig 0.9 ................................... i _ ................ ....... 

vl 

............. 

0 SOOPPY 

A 25OPPU 

0 50 PPY 

s 0 PPU 

... 

......... 1 .............. 

.................. 

0.7 

0 15 30 A5 

I I 

WEEKS ON STUDY 

60 75 

1.0 

-I 

g 0.8 

c 

$ 

>" 5 0.9 

vl 

a 

4 

m 

m 

4 

0.7 

Methylphenidate Hydrochloride, NTP TR 439 

% 

..... 

..... 

2 

....... 

....... 

- 

.... 

i 

90 to5 

....................... 

............ 

12' 

.. 

A 25OPPY 

0 500 SPY 

0 SOPPY 

B 0 PPY 

1 

1 I I 1 

15 I 

30 45 60 75 90 105 I 

WEEKS ON STUDY 

FIGURE 4 

Methylphenidate Hydrochloride in Feed for 2 Years 

Kaplan-Meier Survival Curves for Male and Female Mice Administered 
49 

50. 

20 

15 

50 

45 

2( 

l! 

............... j ................. 

............... i .......... ............ ................................................... :A 

15 30 45 60 75 

WEEKS ON STUOY 

- 

i. 

aj 

6 

..,. 

.... 

.... 

.I 

i 

9c 

0 

;..; .,*. 8 .............. 

0 A 0: 

......A ,.!?A,. ............ 

............................... 

.............................. 

.... 

7 MALE MICE 

I 0 PPU 

0 5OOPPY 

A 25OPPY 

0 5OPPU .... 

I 105 

................ ........................... ........ ~ .................................. ... 

, I 0 PPU 

FEMALE MICE 

0 5OOPPY 

A 25OpPU 

0 5OPYU ..................................................................................... ... 

WEEKS ON STUDY 

15 30 45 60 75 90 105 

Methylphenidate Hydrochloride in Feed for 2 Years 

Growth Curves for Male and Female Mice Administered 

FIGURE 5 
50 Methylphenidate Hydrochloride, NTP TR 439 

of Methylphenidate Hydrochloride 

Mean Body Weights and Survival of Male Mice in the 2-Year Feed Study 

TABLE 14 

Study (9) Survivors (8) controls) Survivors (9) controls) Survivors (9) controls) Survivors 

on Av. Wt. No. of Av. Wt. Wt. (%of No. of Av. Wt. Wt. (%of No. of Av. Wt. Wt. (%of No. of 

Weeks 0 ppm 50 ppm - 250 ppm 500 ppm 

9 

8 

7 

6 

5 

4 

3 

2 

1 

104 

101 

97 

93 

89 

85 

81 

77 

73 

69 

66a 

61 

57 

53 

48 

45 

41a 

37 

33 

29 

25 

21 

17 

14 

13 

12 

11 

10 

45.6 

44.8 

44.6 

45.9 

45.8 

46.1 

46.2 

44.9 

44.3 

43.7 

44.4 

43.0 

43.9 

43.6 

45.3 

45.1 

44.1 

44.1 

42.6 

41.1 

39.4 

37.9 

35.1 

33.0 

32.6 

31.2 

31.1 

30.0 

29.4 

28.5 

28.3 

27.5 

26.7 

25.7 

24.7 

23.4 

21.7 

Mean for weeks 

53-104 44.8 

14-52 

1-13 

40.8 

27.8 

45 

45 

46 

46 

49 

49 

49 

50 

50 

50 

50 

60 

60 

60 

60 

60 

60 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

44.4 

44.8 

45.7 

47.3 

46.1 

46.4 

46.5 

44.7 

44.7 

44.6 

45.5 

44.1 

44.2 

44.9 

45.0 

45.3 

44.4 

44.1 

42.8 

41.5 

40.0 

38.0 

35.1 

32.4 

31.6 

30.6 

30.0 

29.4 

28.5 

28.7 

27.6 

27.4 

26.8 

25.2 

24.3 

23.0 

21.6 

45.3 

40.9 

27.3 

100 

103 

103 

101 

101 

101 

100 

101 

102 

103 

103 

101 

103 

99 

100 

101 

100 

101 

101 

102 

100 

100 

98 

97 

98 

97 

98 

97 

101 

98 

100 

100 

98 

98 

98 

100 

97 

101 

100 

98 

45 

48 

49 

49 

50 

50 

50 

50 

50 

50 

50 

60 

60 

60 

60 

60 

60 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

40.5 

40.8 

41.1 

42.6 

43.0 

42.4 

42.4 

40.7 

41.7 

41.4 

42.0 

40.8 

41.5 

42.1 

42.8 

42.8 

42.1 

41.6 

40.4 

39.4 

38.1 

35.7 

33.2 

30.9 

30.6 

29.5 

29.7 

28.6 

28.2 

28.4 

26.9 

27.0 

25.7 

24.8 

23.9 

22.8 

21.4 

41.6 

38.7 

26.7 

89 

91 

92 

93 

94 

92 

92 

91 

94 

95 

95 

95 

95 

97 

95 

95 

96 

94 

95 

96 

97 

94 

95 

94 

94 

95 

96 

93 

96 

100 

95 

98 

96 

97 

97 

97 

99 

93 

95 

96 

44 

45 

45 

45 

46 

48 

49 

50 

50 

50 

50 

60 

60 

60 

60 

60 

60 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

42.3 

43.1 

43.9 

44.5 

44.3 

44.1 

44.7 

42.6 

42.8 

42.4 

43.1 

41.3 

41.5 

42.0 

42.7 

43.5 

42.7 

42.0 

39.9 

39.4 

37.5 

35.8 

33.5 

3i.5 

30.5 

29.8 

29.2 

28.4 

28.1 

28.5 

27.0 

26.9 

26.0 

25.3 

24.0 

22.2 

21.4 

43.0 

38.9 

26.7 

95 70 

98 70 

97 70 

98 70 

97 70 

95 70 

99 70 

93 41 

96 42 

98 45 

97 45 

97 49 

96 49 

97 50 

95 50 

97 50 

97 50 

97 50 

96 60 

95 60 

96 60 

94 60 

97 ' 60 

97 60 

95 70 

94 70 

96 70 

95 70 

95 70 

95 70 

96 70 

94 70 

96 70 

94 70 

95 70 

96 70 

100 70 

96 

95 

96 

a Interim evaluations occurred during weeks 39 and 65. ' 
Results 51 

of Methylphenidate Hydrochloride 

Mean Body Weights and Survival of Female Mice in the 2-Year Feed Study 

TABLE 15 

on Av. Wt. No. of Av. Wt. Wt. (%of No. of Av. Wt. Wt. (%of No. of Av. Wt. Wt. (%of No. of 

Weeks 0 ppm 50 ppm 250 ppm 500 ppm 

Study (s) Survivors (8) controls) Survivors (g) controls) Survivors (9) controls) Survivors 

9 

8 

7 

6 

5 

4 

3 

2 

1 

105 

102 

98 

94 

90 

86 

82 

78 

73 

69 

66a 

62 

58 

54 

50 

46 

42a 

38 

34 

30 

25 

21 

17 

14 

13 

12 

11 

10 

43.7 

43.5 

43.4 

44.6 

43.5 

44.4 

45.1 

43.1 

42.7 

42.6 

40.8 

41.3 

40.2 

40.1 

41.6 

41.2 

40.1 

39.4 

38.5 

36.0 

34.3 

32.8 

30.4 

27.4 

26.5 

26.1 

25.6 

25.0 

24.0 

23.8 

23.4 

22.5 

21.4 

20.6 

19.8 

18.9 

17.5 

Mean for weeks 

53-105 42.8 

14-52 

1-13 

36.2 

22.7 

37 

40 

42 

43 

44 

45 

47 

47 

47 

47 

47 

57 

57 

57 

58 

58 

58 

68 

68 

68 

68 

68 

68 

68 

68 

68 

68 

69 

69 

69 

69 

69 

69 

69 

69 

69 

69 

42.8 

43.6 

43.8 

44.7 

44.1 

44.0 

43.6 

42.6 

42.5 

41.3 

40.5 

39.8 

39.5 

40.2 

40.9 

40.8 

39.4 

38.5 

37.7 

34.9 

33.5 

32.1 

30.3 

27.6 

26.2 

26.2 

25.6 

25.0 

24.5 

24.1 

23.7 

23.1 

21.8 

20.7 

19.9 

19.0 

18.1 

42.2 

35.6 

22.9 

100 

100 

100 

102 

101 

101 

103 

102 

101 

101 

101 

103 

98 

100 

101 

100 

101 

99 

97 

99 

100 

97 

99 

96 

98 

100 

98 

99 

98 

98 

98 

97 

98 

98 

100 

101 

99 

99 

98 

101 

36 

36 

40 

40 

42 

43 

44 

44 

44 

44 

45 

55 

55 

56 

56 

56 

56 

65 

65 

65 

65 

66 

67 

68 

68 

68 

68 

68 

68 

68 

68 

68 

68 

68 

68 

69 

69 

40.7 

41.0 

42.4 

43.9 

44.1 

44.1 

43.2 

42.4 

42.1 

41.9 

40.4 

39.7 

38.8 

40.0 

40.3 

40.6 

38.9 

38.1 

37.1 

34.7 

33.8 

31.1 

28.9 

25.9 

25.3 

25.3 

24.5 

24.1 

23.3 

22.8 

22.9 

22.7 

21.7 

20.7 

19.5 

18.7 

17.8 

41.8 

34.9 

22.3 

93 

94 

98 

98 

101 

99 

96 

98 

99 

98 

99 

96 

97 

100 

97 

99 

97 

97 

96 

96 

99 

95 

95 

95 

96 

97 

96 

96 

97 

96 

98 

101 

101 

101 

99 

99 

102 

98 

96 

98 

37 

40 

44 

45 

45 

46 

47 

47 

47 

47 

48 

58 

58 

58 

58 

58 

58 

68 

68 

68 

69 

69 

69 

69 

69 

69 

69 

69 

69 

70 

70 

70 

70 

70 

70 

70 

70 

42.4 

43.3 

44.7 

44.3 

44.8 

45.1 

45.7 

44.0 

43.6 

43.1 

41.4 

41.1 

40.1 

41.6 

41.3 

41.9 

40.7 

39.4 

38.6 

36.4 

35.3 

33.0 

29.8 

26.8 

25.9 

25.6 

24.9 

24.7 

24.1 

23.3 

22.7 

22.4 

21.8 

20.6 

19.7 

18.9 

18.0 

43.2 

36.3 

22.5 

103 

102 

101 

102 

102 

101 

102 

100 

100 

104 

99 

102 

102 

100 

100 

101 

103 

101 

98 

98 

98 

98 

97 

99 

100 

98 

97 

100 

102 

100 

100 

100 

103 

97 

100 

103 

99 

101 

100 

99 

44 

44 

46 

49 

50 

50 

50 

50 

50 

50 

50 

60 

60 

60 

60 

60 

60 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

70 

a Interim evaluations occurred during weeks 40 and 65. 
52 Methylphenidate Hydrochloride, NTP TR 439 

female mice. 

ed in Appendix C for male mice and Appendix D for 

the neoplasms mentioned in this section are presentleast one animal group, and historical incidences for 

that occurred with an incidence of at least 5% in at 

diagnoses, statistical analyses of primary neoplasms 

nonneoplastic lesions, individual animal tumor 

lung. Summaries of the incidences of neoplasms and 

neoplasms and nonneoplastic lesions in the liver and 

biologically noteworthy changes in the incidences of 

This section describes the statistically significant or 

Pathology and Statistical Evaluation 

were generally similar to those of the controls. 

absolute and relative organ weights of exposed mice 

were also increased in exposed female groups. Other 

females (Tables F7 and F8). Relative liver weights 

absolute liver weights of all exposed groups of 

were greater than those of the controls, as were the 

males except those exposed to 50 ppm at 9 months 

the relative liver weights of all groups of exposed 

Liver: At the 9- and 15-month interim evaluations, 

hepatoblastoma and the combined incidence of 

The incidences of hepatocellular adenoma and 

hydrochloride administration. 

males were considered related to methylphenidate 

female mice and in hepatoblastomas in 500 ppm 

adenomas and eosinophilic foci in 500 ppm male and 

ative liver lesions. The increased incidences of 

spectrum that constitutes the progression of proliferhepatocellular carcinoma are thought to represent a 

tocellular alteration, hepatocellular adenoma, and 

and females (Tables 16, C5, and D5). Foci of hepaof eosinophilic foci was increased in 500 ppm males 

1/1,363 female historical control mice. The incidence 

is a rare neoplasm, occurring in 0/1,366 male and 

hepatoblastoma in 500 ppm males. Hepatoblastoma 

ally, there was a significantly increased incidence of 

exposed animals with multiple adenomas. Additionstudies. There was also an increase in the number of 

females is far above the control rate of any of the 

current historical database, and the rate in 500 ppm 

observed in all but one of the studies included in the 

500 ppm males in this study exceeds the rate 

500 ppm females (Tables 16 and D3). The rate in 

(combined) were also significantly increased in 

incidences of adenoma and adenoma or carcinoma 

in 500 ppm male mice (Tables 16 and C3). The 

hepatocellular neoplasms were significantly increased 
Results 53 

of Methylphenidate Hydrochloride 

Incidences of Neoplasms and Nonneoplastic Lesions of the Liver of Mice in the 2-Year Feed Study 

TABLE 16 

Live+ 

9-Month Interim Evaluation 

Male 

0 

10 

0 

0 

0 

0 

Eosinophilic Focib 

Hepatoblastoma 

Hepatocellular Carcinoma 

Hepatocellular Adenoma, Multiple 

Hepatocellular Adenoma 

Liver 

15-Month Interim Evaluation 

1 

0 

1 

0 

10 

0 

0 

0 

2 

All Foci 

Eosinophilic Foci 

Clear Cell Foci 

Basophilic Foci 

Hepatoblastoma 

Hepatocellular Carcinoma 

Hepatocellular Adenoma, Multiple 

Hepatocellular Adenoma 

Liver 

2-Year Study 

9 

6 

4 

1 

50 

5 

All Foci 

Eosinophilic Foci 

Clear Cell Foci 

Basophilic Foci 

Hepatocellular Adenoma (single or multiple) 

Hepatocellular Adenoma, Multiple 

Logistic regression testsf 

First incidence (days) 

Terminal ratese 

Adjusted ratad 

Overall ratesC 

P=O.O09 

679 

17/45 (38%) 

39.1% 

18/50 (36%) 

Hepatocellular Carcinoma 

Logistic regression tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

P=O.396 

537 

7/45 (16%) 

20.7% 

10/50 (20%) 

(continued) 

0 

10 

0 

0 

0 

30 

1 

1 

0 

0 

10 

0 

0 

0 

0 

12 

8 

3 

2 

50 

10 

P=0.524N 

I20 

17/45 (38%) 

39.1% 

18/50 (36%) 

P=0.598N 

707 

8/45 (18%) 

19.5% 

9/50 (18%) 

0 

10 

0 

0 

0 

1 

2 

0 

1 

1 

10 

0 

0 

0 

1 

14 

9 

2 

4 

50 

6 

P=0.437N 

610 

15/44 (34%) 

35.5% 

16/50 (32%) 

P=O.101 

541 

12/44 (27%) 

34.7% 

17/50 (34%) 

0 

10 

0 

0 

0 

0 

1 

0 

0 

1 

10 

0 

1 

1 

1 

18* 

14. 

6 

0 

50 

14' 

P=O.O20 

618 

25/41 (61%) 

64.2% 

29/50 (58%) 

P=O.564 

574 

6/41 (15%) 

23.4% 

11/50 (22%) 
54 Methylphenidate Hydrochloride, NTP TR 439 

of Methylphenidate Hydrochloride (continued) 

Incidences of Neoplasms and Nonneoplastic Lesions of the Liver of Mice in the 2-Year Feed Study 

TABLE 16 

Male (continued) 

2-Year Study (continued) 

Logistic regression tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

Hepatoblastornag 

P=O.O04 P=O.SOO P=O.496 P=O.O26 

4 

0/45 (0%) 1/45 (2%) 1/44 (2%) 5/41 (12%) 

0.0% 2.2% 2.3% 12.2% 

0/50 (0%) 1/50 (2%) 1/50 (2%) 5/50 (10%) 

730 cr) 730 0 730 (T) 

P=O.O16 P=0.505N P=O.444 P=O.O37 

537 707 541 

21/45 (47%)21/45 (47%)21/44 (48%)27/41 (66%) 

49.9% 48.9% 53.0% 70.7% 

24/50 (48%) 23/50 (46%) 26/50 (52%) 34/50 (68%)

Hepatocellular Adenoma, Carcinoma, or Hepatoblastomai 

Logistic regression tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

Female 

Liver 

9-Month Interim Evaluation 

All Foci 

Eosinophilic Foci 

Hepatocellular Carcinoma 

Hepatocellular Adenoma, Multiple 

Hepatocellular Adenoma 

Liver 

15-Month Interim Evaluation 

All Foci 

Eosinophilic Foci 

Basophilic Foci 

Hepatocellular Carcinoma 

Hepatocellular Adenoma, Multiple 

Hepatocellular Adenoma 

0 

0. 

10 

0 

0 

0 

0 

0 

0 

10 

0 

0 

1 

0 

0 

9 

0 

0 

10 

0 

0 

0 

0 

0 

0 

0 

0 

0 

10 

3 

2 

1 

10 

0 

0 

1 

0 

0 

1 

1 

1 

10 

0 

0 

0 

1 

1 

0 

10 

0 

0 

1 

(continued) 
Results 55 

of Methylphenidate Hydrochloride (continued) 

Incidences of Neoplasms and Nonneoplastic Lesions of the Liver of Mice in the 2-Year Feed Study 

TABLE 16 

Liver 

2-Year Study 

Female (continued) 

All Foci 

Eosinophilic Foci 

Clear Cell Foci 

Basophilic Foci 

5 

3 

0 

2 

49 

8 

3 

2 

4 

48 

11 

8 

2 

2 

49 

26.' 

25'. 

0 

1 

50 

Hepatocellular Adenoma (single or multiple) 

Hepatocellular Adenoma, Multiple 2 0 3 IS** J 

Logistic regression tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

6/37 (16%) 8/35 (23%) 27/44 (61%) 

16.2% 26.6% 26.1% 62.2% 

6/49 (12%)10/48 (21%)10/49 (20%) 28/50 (56%) 

PCO.001 P=O.164 P=O.220 P < 0.001 

588 689 690 

9/37 (24%) 

739 (T> 

Hepatocellular Carcinoma 

Logistic regression tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 5/49 (10%) 

5/37 (14%) 2/35 (6%) 2/37 (5%) 5/44 (11%) 

13.5% 8.3% 5.4% 3.2% 

3/48 (6%) 2/49 (4%) 6/50 (12%) 

P=O.430 P=0.383N P=0.215N P=O.575 

739 (9 730 739 0 660 

Hepatocellular Adenoma or Carcinomd 

Logistic regression tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

PCO.001 P=O.335 P=O.427 PCO.001 

588 689 660 

10/37 (27%) 28/44 (64%) 

24.3% 28.7% 28.7% 65.2% 

9/49 (18%) 11/48 (23%) 11/49 (22%) 30/50 (60%) 

739 (T> 

9/37 (24%) 8/35 (23%) 

a Number of animals with organ examined microscopically 

(T) Terminal sacrifice 

** PSO.01 

l Significantly different (PSO.05) from the control group by the logistic regression test. 

Kaplan-Meier estimated neoplasm incidence at the end of the study after adjustment for intercurrent mortality 

Number of animals with neoplasm per number of animals necropsied 

Number of animals with lesion 

neoplasms in animals dying prior to terminal kill as nonfatal. A lower incidence in an exposure group is indicated by N. 

P value8 corresponding to pairwise comparisons between the controls and that exposed group. The logistic regression test regards 

Beneath the control incidence are the P values associated with the trend test. Beneath the exposed group incidence are the 

(35.5% k 14.3%); range 10%-68% 

Historical incidence for 2-year feed studies with untreated control groups (mean f standard deviation): 485/1,366 

Not applicable; no neoplasms in animal group 

e Observed incidence at terminal kill 

g Historical incidence: 0/1,366 

j Historical incidence: 223/1,363 (16.4% k 10.7%); range 3%-42% 
56 Methylphenidate Hydrochloride, NTP TR 439 

to methylphenidate hydrochloride administration. 

the positive trend in females were considered related 

rates. Neither the decreased incidence in males nor 

groups are more consistent with historical control 

historical rates, while the incidences in exposed 

rates in control groups vary greatly from average 

with a range of 2% to 26%. In the present study, 

of 4% to 30%, and for female mice is 106/1,371(8%) 

bined) for male mice is 242/1,369 (18%) with a range 

alveolar/bronchiolar adenomas or carcinomas (comhistorical control rate in recent NTP feed studies for 

(1/48, 1/49, 6/50, 7/50) (Tables C3 and D3). The 

6/50), and a positive trend in the number in females 

carcinomas (combined) in males (16/50, 10/50, 9/50, 

the number of alveolar/bronchiolar adenomas or 

Lung: There was a marginally significant decrease in 

GENETIC TOXICOLOGY 

10,000 pg/plate tested at SRI, International. 

tested to 5,000 pg/plate, compared to the 

Microbiological Associates, limiting the highest dose 

of toxicity was noted in the tests performed at 

(Table El; Mortelmans et al., 1986). A slight degree 

Sprague-Dawley rat or Syrian hamster liver S9 

with and without Aroclor 1254-induced male 

TA1535, or TA1537 when tested at two laboratories 

Salmonella ryphimurium strain TA97, TA98, TA100, 

Methylphenidate hydrochloride was not mutagenic in 

first trial did not repeat in a second trial, and the 

S9, a weakly positive response observed at LBI in the 

much higher doses than those tested at EHRT. With 

the positive response ranged from 702 to 900 pg/mL, 

phenidate hydrochloride. The doses that produced 

cycle delay induced by treatment with methylharvest time of 26 hours to offset the severe cell 

trial were harvested 10 hours later than the normal 

presented in Galloway et al., 1987). The cells in this 

doses in the test performed without S9 (data 

positive response was obtained at all three scorable 

without S9. At Litton Bionetics, Inc. (LBI), a 

(EHRT), negative results were obtained with and 

Environmental Health Research and Testing 

the sister chromatid exchange test performed at 

higher doses of methylphenidate hydrochloride. In 

responses were recorded in tests that employed 

examination of the data shows that the positive 

between two laboratories. However, closer 

(Table E2) and chromosomal aberrations (Table E3) 

obtained for induction of sister chromatid exchanges 

ovary cells, apparently inconsistent results were 

In cytogenetic tests with cultured Chinese hamster 

at EHRT. 

the sister chromatid exchange test with S9 performed 

be negative. This latter result was in agreement with 

sister chromatid exchange test with S9 was judged to 

not repeated. 

at each of the three doses scored. These tests were 

increases in chromosomal aberrations were observed 

(highest dose, 1,250 pg/mL) but with S9, significant 

chromosomal aberrations was observed without S9 

considered to be equivocal. At LBI, no increase in 

trial, the overall results of the test with S9 were 

aberrations was seen at this dose level in the first 

However, because no increase in chromosomal 

at the highest scorable dose (1,500 pg/mL). 

showed a strong increase in chromosomal aberrations 

first trial were again negative, while the second trial 

(1,750 and 2,000 pg/mL). With S9, results of the 

produced positive responses at the two highest doses 

trial, but a second trial conducted with higher doses 

chromosomal aberrations were observed in the first 

were performed. No significant increases in 

EHRT gave positive results without S9. Two trials 

The chromosomal aberrations test performed at 

predictivity of the Salmonella assay. 

in vitro genetic toxicity tests improved upon the 

is also important to note that no combination of 

aberrations were positive in the rodent bioassay. It 

and 73% of chemicals that induce chromosomal 

chemicals that. induced sister chromatid exchanges 

Salmonella assay for rodent carcinogenicity: 64% of 

studies are less predictive than positive results in the 

cultured Chinese hamster ovary cell cytogenetic 

also found to be noncarcinogens. Positive results in 

precise. Approximately 50% of nonmutagens were 

and/or mice), the negative predictivity was less 

of Salmonella mutagens were carcinogens in rats 

a good predictor of carcinogenicity in rodents (89% 

positive result in the Salmonella test was shown to be 

tissue sites (Ashby and Tennant, 1991). Although a 

carcinogenicity in rats and mice at single or multiple 

DNA reactivity), mutagenicity in Salmonella, and 

electrophilicity of a chemical (structural alert to 

correlation was found to exist among the potential 

(Tennant et al., 1987; Zeiger et al., 1990). A strong 

their predictive value for odent carcinogenicity 

evaluated these mutagenicity tests with respect to 

exchanges in mammalian cells in vitro. The NTP has 

chromosomal aberrations and sister chromatid 

mutations inSalmonella, but did induce 

Methylphenidate hydrochloride did not induce * 
57 

DISCUSSION AND CONCLUSIONS 

the chemical. 

response of rodents to long-term administration of 

designed primarily to determine the carcinogenic 

performed by the National Toxicology Program were 

toxicity and carcinogenicity testing. The studies 

the Food and Drug Administration nominated it for 

effects of this drug, the National Cancer Institute and 

Because there is little information on the long-term 

ment of attention-deficit disorders and narcolepsy. 

Methylphenidate hydrochloride is used in the treattoxicity observed. 

used in these rodent studies may account for the 

1974), and these differences or the higher dose levels 

methylphenidate metabolites occur (Faraj et al., 

1990). Quantitative differences in rodent and human 

1972; BarMey et al., 1990; Goodman and Gilman’s, 

ed with the intake of methylphenidate (Goodman, 

studies reporting any definitive liver lesions associatmon side effect in humans, and there have been no 

mice. Liver toxicity has not been reported as a comliver and lower mean body weight gain in rats and 

chemical-related findings were toxicity to the mouse 

In the 14-day and 13-week studies, the principal 

(Barone et aL, 1979). 

12 mgkg has no effect on daily consumption by rats 

ad libitum basis, methylphenidate at oral doses up to 

et al., 1975), but when feed is available on a 24-hour 

Howard, 1959; Roskowski and Kelley, 1963; Warawa 

hours after drug administration (Karczmar and 

rodents, feed consumption is reduced for several 

When methylphenidate hydrochloride is given to 

anorexic effects of methylphenidate are transient. 

studies reported in the literature that show that any 

exposed and control groups. This is consistent with 

2 weeks feed consumption was similar among 

phenidate hydrochloride treatment, but after 1 or 

reported during the first or second week of methylDecreases in feed consumption by rats and mice were 

the lower dose levels used in the 2-year studies. 

increase in activity was reported in rats or mice at 

2,000 ppm female rats in the 13-week studies, but no 

exposed to 4,000 ppm in the 14-day studies and in 

treatment in male and female rats and male mice 

Hyperactivity was reported during the first weeks of 

Christensen, 1972). 

levels (40 to 100 mgkg) (Fog, 1969; Pedersen and 

administration of methylphenidate at higher dose 

occur in rodents within several hours after oral 

1983). Increases in activity or stereotyped behavior 

administration (Smith and Isaac, 1980; Wargin et al., 

levels of the drug are reached after intraperitoneal 

oral administration, probably because higher plasma 

after intraperitoneal administration, but not after 

increases locomotive activity in rats within 1 hour 

doses of 3.2 and 6.4 mgkg, methylphenidate 

behavior increased (Bhattacharyya er al., 1980). At 

spontaneous motor activity decreased but stereotyped 

(Hughes and Greig, 1976). With increasing dose, 

the behavioral effects can vary with dose level 

produce the same degree of increased activity, and 

(intraperitoneal injection), a 16 mgkg dose does not 

that while ambulation in rats is increased at 8 mgkg 

dopamine in the brain. Other studies have shown 

these effects are correlated with increased levels of 

after intraperitoneal doses of 5 to 20 mgkg, and 

spontaneous motor activity and stereotyped behavior 

contradictory. In rats methylphenidate increases 

motor activity are complex and sometimes seem 

et al., 1983). The dose-response relationships for 

phenidate treatment (Smith and Isaac, 1980; Wargin 

locomotive activity within 1 to 2 hours of methylOther rodent studies have shown an increase in 

develop. 

tolerance to the hyperactive effects of the drug may 

maximum intake of chemical in the feed at night, and 

increase in activity would probably correspond to the 

lower doses than the 14-day and 13-week studies; any 

due to the fact that these studies were conducted at 

observe hyperactivity in the 2-year studies may be 

treatment (Fregly and Black, 1964). The failure to 

ment, tolerance appears to develop by day 4 to 6 of 

motor activity in rats for the first few days of treatof methylphenidate cause increased spontaneous 

(Swanson et al., 1986). While oral doses of 62 mgkg 

the mechanism for such an effect is not known 

phenidate has been reported in children, although 

Tolerance to the therapeutic effects of methylas to whether methylphenidate affects growth 

There have been conflicting reports in the literature 
58 Methylphenidate Hydrochloride, NTP TR 439 

with subcutaneous or bolus oral administration. 

results in lower plasma levels of the drug than occur 

tion, administration of the chemical in feed probably 

any, of methylphenidate on bone growth. In addiolder animals may not be sensitive to an effect, if 

when the animals were 7 to 8 weeks old, and these 

1987). Dosing of animals in the NTP studies started 

reversible upon cessation of treatment (Pizzi et al., 

reduction in growth observed in the younger rats was 

but not in 55-day-old rats similarly treated. The 

phenidate twice a day from 5 days of age to 24 days, 

observed in rats treated with 35 mgkg methyl1980). A small reduction in femur length was 

discontinuation of treatment (Greeley and Kizer, 

juvenile rats. These effects were reversible upon 

100 mgkg administered twice daily to neonatal or 

skeletal growth at subcutaneous doses of 35 and 

day) in rats. Other studies show depression of 

13 weeks at doses up to 2,OOO ppm (80 mgkg per 

treatment-related effects on bone density or length at 

included in the 13-week rat study. There were no 

measurements of bone density and length were 

Gittelman, 1983), and because of this concern 

patterns in children (Roche et al., 1979; Mattes and 

Aylward, 1992). 

clinical study (Whalen and Henker, 1991; Kelley and 

on growth in children remains an area of ongoing 

1980). The effect of methylphenidate hydrochloride 

growth hormone levels (females) (Greeley and Kizer, 

serum prolactin levels (males and females) and 

subcutaneously twice daily for 21' days had depressed 

10, 35, or 100 mgkg methylphenidate hydrochloride 

1987; Shaywitz et al., 1990). Rats administered 1, 3, 

after methylphenidate treatment (Weizman ef al., 

hormone and decreases in serum prolactin levels 

other investigators found increases in serum growth 

with methylphenidate for a mean of 15 months, while 

hormone or prolactin profiles in children treated 

reported no significant differences in 24-hour growth 

changes in hormone levels. Schultz et al. (1982) 

ment have focused on the effects on growth and 

Studies on side effects from methylphenidate treatThe final mean body weights of 500 and 1,000 ppm 

weights which progressed with length of exposure. 

mice. In exposed rats there were lower mean body 

absolute and/or relative liver weights of exposed 

survival in rats or mice. There were increases in the 

chloride, there were no treatment-related effects on 

In the 2-year feed studies of methylphenidate hydroparison (Table 17). 

human dose levels based on a body weight comdelivered to rats and mice were 40 to 60 times 

estimated doses of methylphenidate hydrochloride 

was probably due to pharmacologic effects. The 

of methylphenidate hydrochloride on body weight 

exposed groups was similar, indicating that the effect 

2-year studies feed consumption by control and 

and 7% lower than those of the controls. In these 

weights of 500 ppm male and female mice were 3% 

was less than that in rats; the final mean body 

those of the controls. The body weight effect in mice 

male and female rats were 5% to 22% lower than 

may have been tolerated. 

body weight effects were lessevere and higher doses 

the drug as it ages. In the 2-year mouse study the 

related to differences in how the animal responds to 

the body weight effect in the 2-year rat study may be 

(Gurian and Rosowsky, 1990), and the progression of 

lower levels of the drug than younger patients 

(NTP, 1991). In humans, older patients respond to 

is consistent with the findings for amphetamine 

tolerance to the body weight effects developed, which 

In the 2-year rat study there was no indication that 

increased in high-dose mice. 

carcinomas, or hepatoblastomas (males) was 

the combined incidence of hepatocellular adenomas, 

hepatocellular carcinomas alone was not increased, 

hepatocellular adenomas. While the incidence of 

increase in the number of animals with multiple 

eosinophilic foci and total foci in the liver, and an 

dose mice there was an increase in the incidence of 

500 ppm male and female mice. In addition, in highincreased incidence in hepatocellular neoplasms in 

evidence of carcinogenic activity based on an 

male or female rats, but in mice there was some 

There was no evidence of carcinogenic activity in 

typic (and possibly genotypic) variant of a malignant 

to a more malignant state, simply represent a phenotive, and rather than representing further progression 

hepatoblastomas comprise cells that are more primision of proliferative lesions. It is probable that 

biological and morphological continuum in progresHyperplasia, adenoma, and carcinoma represent a 

dose, one mid-dose, and five high-dose male mice. 

cells (Shiojiri et aL, 1991)J were found in one lowHepatoblastomas [thought to arise from liver stem 
Discussion and Conclusions 59 

Comparison of Doses in Methylphenidate Hydrochloride 2-Year Feed Studiesa 

TABLE 17 

Males Females 

Rats 

Dose in ppm 

mg/m2 

mg methylphenidate/kg body weight 

Grams feedlday 

0 100 500 1,000 0 100 500 1,000 

16.2 16.3 16.0 16.1 12.2 12.2 11.9 11.2 

0 4 20 42 0 4 22 47 

0 21 104 218 0 20 114 244 

Mice 

Dose in ppm 0 50 250 500 0 50 250 500 

mg/m2 

mg rnethylphenidatekg body weight 

Grams feedlday 4.7 4.8 4.7 4.8 5.7 5.6 5.7 5.7 

0 5.3 28.3 55.9 0 6.7 34.2 66.5 

0 15 84 168 0 21 102 198 

Humans 

11-37 

0.3-1.0 

a The dose is calculated as an average for > 52 weeks. Calculation for body surface area dose based on Freireich et ul., 1966; 

height-to-body-weight ratios.) 

mg/m2 = K,,p (dose in rng/kg) where K,,, is 37 for humans, 5.2 for rats, and 3.0 for mice. (K,,, is a conversion based on average 

neoplasms. 

effect on the liver, or at least on the hepatocellular 

indicate that methylphenidate hydrochloride had an 

istration, the presence of these neoplasms appears to 

in relatively high numbers only after chemical adminHowever, because hepatoblastomas are rare and seen 

interpreting the carcinogenic potential of a chemical. 

toma with those of adenoma and carcinoma when 

appropriate to combine the incidences of hepatoblashepatocellular neoplasms (mostly carcinomas), it is 

hepatoblastomas are generally observed within 

hepatoblastomas and carcinomas appear similar and 

liver neoplasm. Because the malignant potential of 

groups. This incidence of total hepatocellular 

neoplasms was increased only in the high dose 

category because the incidence of hepatocellular 

strong enough to place it in the "clear evidence" 

evidence for carcinogenicity was not considered to be 

high-dose groups of male and female mice. The 

eosinophilic foci and hepatocellular neoplasms in the 

carcinogenic effect because there was an increase in 

This was considered to represent some evidence of a 

males, and was not increased for females. 

neoplasms was within the historical control range for 

research is needed to characterize the mechanism by 

preneoplastic foci (Cattley and Popp, 1989). Further 

genotoxic agents might promote the growth of 

1989; Reddy and Rao, 1989). Alternatively, nonexpression of endogenous mutations (Nemali et al., 

cell proliferation, and an increased potential for 

increase in liver toxicity and subsequent increase in 

nism for mouse liver carcinogenicity includes an 

liver neoplasms is not known. One proposed mechaS. typhimurium negative chemicals produce mouse 

which methylphenidate hydrochloride and these other 

(Tennant and Ashby, 1991). The mechanism <by 

these 61% were negative in the S. typhimurium test 

to produce neoplasms only in the mouse liver, and of 

term rodent studies, 55 of 301 chemicals were found 

a direct genotoxic effect. In a recent review of longneoplasms may be related to mechanisms other than 

mechanism for the formation of the mouse liver 

Salmonella typhimurium assay. This suggests that the 

Methylphenidate was not mutagenic in the 
60 Methylphenidate Hydrochloride, NTP TR 439 

interacts with components of liver cells. 

and the manner in which this nonmutagenic chemical 

which methylphenidate produces mouse liver toxicity 

may facilitate the clonal expansion of initiated cells. 

cell proliferation found in the focal liver lesions that 

time (Rabes, 1988). It is this property of enhanced 

by enhanced cell proliferation which increases with 

1981). Foci of altered hepatocytes are characterized 

(Rabes and Szymkowiak, 1979; Barbason and Betz, 

after cessation of exposure to certain carcinogens 

with continued carcinogen exposure or with time 

Scherer, 1980). Foci increase in number and size 

related to the dose of the carcinogen (Emmelot and 

carcinogens, and the numbers of induced foci are 

which show that foci are rapidly induced by hepatois based on ,studies conducted primarily in the rat 

(Bannasch and Zerban, 1992). The evidence for this 

studies, are considered to be preneoplastic lesions 

of altered hepatocytes, as were observed in these 

includes a series of stepwise cellular changes. Foci 

rodent liver carcinogenicity induced by chemicals 

is a multistep process (Barrett, 1992) and that in the 

It is generally accepted that chemical carcinogenesis 

are not available. 

oncogene changes with methylphenidate treatment 

1987; Fox ef al., 1990); at this time, information on 

induced liver neoplasms may vary (Reynolds et af., 

gene changes from spontaneous and chemicalfrom a normal cell to a neoplastic cell. The oncoearly change which may be one step in the evolution 

activation in hepatocellular foci may represent an 

normal liver tissue. The increase in ras oncogene 

42% of hepatocellular carcinomas but in only 7% of 

cellular foci, 44% of hepatocellular adenomas, and 

the H-ras oncogene was activated in 29% of hepatopathology specimens. In this study it was found that 

mice as measured in tissues obtained from archival 

nomas that arose spontaneously in control B6C3Fl 

carcinogenesis in hepatic foci, adenomas, and carcireported on the molecular events in murine hepatogenes (Barrett, 1992). Richardson ef al. (1992) 

found in carcinogenesis has been mutations in ras 

during multistep carcinogenesis, and an early change 

A series of genetic changes is proposed to occur 

that occurs naturally in this animal [historical range 

13/50; 500 ppm, 6/50; 1,000 ppm, 5/50), a neoplasm 

adenomas in the female rat (control, 15/50; 100 ppm, 

reduced the incidence of mammary gland fibroTreatment with methylphenidate hydrochloride 

lactin levels (Ravitz and Moore, 1977). 

thought to have the potential to lower serum proadenomas in the female rat (NTP, 1991) and is also 

also reduces the incidence of mammary gland fibrohormonal effects of methylphenidate. Amphetamine 

fibroadenomas in female rats may be related to these 

the lower incidence of spontaneous mammary gland 

serum prolactin, levels (Greeley and Kizer, 1980), and 

1987). Methylphenidate has been reported to lower 

growth of these neoplasms (Briand, 1983; Kleinberg, 

rodents, and prolactin lowering drugs inhibit the 

chemical-induced mammary gland neoplasms in 

in serum prolactin levels potentiate the formation of 

female rats by 11% and 22%, respectively. Increases 

weights were also reduced in the mid- and high-dose 

58% with a mean of 39% (484/1,251)]. Mean body 

for this neoplasm in control female rats is 8% to 

observed decrease in mammary gland neoplasms. 

of methylphenidate are one hypothesis for the 

bong et al., 1983), and these neuroendocrine effects 

prolactin concentration (Costall and Naylor, 1974; 

hypothalamus release of PIF, and decrease serum 

anticipated to. increase release of dopamine, increase 

dopaminergic activity of methylphenidate would be 

positive breast cell lines (Manni ef al., 1986). The 

have a growth promoting effect on estrogen-receptor 

human breast neoplasms, prolactin was shown to 

(Blankenstein et al., 1984). Using in vitro strains of 

increase inthe susceptibility to tumorigenesis 

synthesis in the mammary gland and a concomitant 

levels will result in an increase in the rate of DNA 

suggested that increases in estrogen and prolactin 

(Archer, 1977; Long et al., 1983). It has been 

which would result in decreases in serum prolactin 

and methylphenidate may increase the release of PIF, 

in dopamine levels such as seen with amphetamine 

is controlled by dopaminergic neurons, and increases 

prolactin-inhibiting factor (PIF). Hypothalamic PIF 

is regulated by a hypothalamic factor known as 

Musey et al. , 1987). Secretion of pituitary prolactin 

gland neoplasms is still under study (Kleinberg, 1987; 

The role of prolactin in the growth of mammary 

in dosed female rats, the decreases in the incidence 

Because methylphenidate caused lower body weights 

neoplasms of the mammary gland in female rats. 

naturally occurring benign neoplasms including 

associated with a decrease in the incidences of 

who found that decreases in rat body weight were 

mary gland neoplasms is offered by Rao et al. (1987), 

An alternative hypothesis for the decrease in mam- 
Discussion and Conclusions 61 

Bruning, 1987). 

plasms (Cave and Jurkowski, 1984; Welsch, 1985; 

increases in the incidence of mammary gland neoincreased levels of dietary fat are associated with 

this lower body weight. Other studies report that 

of mammary gland neoplasms may also be related to 

treatment. 

was uncertain if this effect was related to chemical 

historical range for this neoplasm in controls and it 

The incidence for this neoplasm was within the 

by pairwise comparison but not by the trend statistic. 

10/50) was marginally decreased in treated male rats 

cytomas of the adrenal medulla (18/49, 7/48, 5/49, 

The incidence of benign or malignant pheochromofibroadenomas and uterine polyps in female rats, of 

pheochromocytomas in male rats, of mammary gland 

plasms in rats and mice, of the incidence of adrenal 

treatment caused decreased incidences of total neogenic activity in either rats or mice. Amphetamine 

studies, in which there was no evidence of carcinoplasms were more marked in the amphetamine 

spectrum of decreases in naturally occurring neothe female rats. The lower body weights and the 

decreased incidence of mammary gland neoplasms in 

drugs, both chemicals caused lower body weights and 

et af., 1990). In the NTP long-term studies of these 

attention-deficit hyperactivity disorders (Pelham 

(Figure 6; Julien, 1975) used in the treatment of 

Methylphenidate and amphetamine are related drugs 

duration with methylphenidate (Zaczek et af., 1989). 

after treatment with amphetamine but is of short 

brain monoamine markers lasts for up to 18 hours 

1976; Pechnik ef al., 1979), and that depletion of rat 

observed with methylphenidate (Hughes and Greig, 

increased activity in rats at lower doses than 

studies which show that mphetamine causes 

phenidate studies. This is consistent with other 

this side effect was not observed in the methylday for rodents on amphetamine treatment, while 

female mice. Hyperactivity was noted throughout the 

liver neoplasms, and lung neoplasms in male and 

and female mice, and of harderian gland adenomas, 

pituitary gland adenomas in male and female rats 

CONCLUSIONS 

neoplasms. 

mice based on the occurrence of hepatocellular 

phenidate hydrochloride in male and female B6C3F1 

was some evidence of carcinogenic activity of methylF344/N rats receiving 100,500, or 1,000 ppm. There 

methylphenidate hydrochloride in male or female 

there was no evidence of carcinogenic activity* of 

Under the conditions of these 2-year feed studies 

eosinophilic foci. 

and female mice resulted in increased incidences of 

istration of methylphenidate hydrochloride to male 

incidence of mammary gland fibroadenomas. Adminhydrochloride was associated with a decrease in the 

Treatment of female rats with methylphenidate 

* Explanation of Levels of Evidence of Carcinogenic Activity is on page 9. A summary of the Technical Reports RMew Subcommittee 

comments and the public discussion on this Technical Report appears on page 11. 
62 Methylphenidate Hydrochloride, NTP TR 439 

H H 

H- C 

H- N C- H 

\/ \H 

H-C---- H 

Amphetamine 

H- C C- H 

I I 

H- C 

H- N C- H 

\/ \H 

H-C- COOCHJ 

Methylphenidate (Ritalin) 

(Mien, 1975) 

Structural Formulas of Amphetamine and Methylphenidate (Ritalin) 

FIGURE 6
63 

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71 

OF METHYLPHENIDATE HYDROCHLORIDE 

SUMMARY OF LESIONS IN MALE RATS 

APPENDIX A 

IN THE 2-YEAR FEED STUDY 

TABLE A1 Summary of the Incidence of Neoplasms in Male Rats 

TABLE A2 Individual Animal Tumor Pathology of Male Rats 

TABLE A3 Statistical Analysis of Primary Neoplasms in Male Rats 

TABLE A4 Historical Incidence of Adrenal Medulla Pheochromocytomas 

TABLE A5 Summary of the Incidence of Nonneoplastic Lesions in Male Rats 

in the 2-Year Feed Study of Methylphenidate Hydrochloride 

in Untreated Male F344M Rats 

in the 2-Year Feed Study of Methylphenidate Hydrochloride 

in the 2-Year Feed Study of Methylphenidate Hydrochloride 

in the 2-Year Feed Study of Methylphenidate Hydrochloride .................... 

101 

100 

96 

78 

73 

.................... 

.................... 

......................................... 

.................... 
72 Methylphenidate Hydrochloride, NTP TR 439 
Lesions in Male Rats 73 

Summary of the Incidence of Neoplasms in Male Rats in the 2-Year Feed Study of Methylphenidate Hydrochloridea 

TABLE A1 

0 PPm 100 ppm 500 ppm 1,000 ppm 

Early deaths 

ls-”r intcrinr evolicolien 

PM&intaimevolicolien 

Animals initially in study 

Disposition Summary 

Natural deaths 

Moribund 

Accidental deaths 

Terminal sacrifice 

Died last week of study 

SuMvors 

Animals examined microscopically 

10 

10 

70 

8 

14 

70 

28 

10 

10 

70 

7 

9 

1 

33 

70 

10 

10 

70 

9 

7 

70 

34 

10 

9 

70 

8 

9 

33 

1 

70 

9-Month Interim Evaluation 

Testes 

Genital Systemb 

(10) (10) (10) 

Interstitial cell, adenoma 

(9) 

1 (11%) 

15-Month Interim Evaluation 

None 

Alimentary System 

None 

Cardiovascular System 

Endocrine System 

Adrenal medulla 

Adenoma 

Adrenal cortex 

C-cell, adenoma 

Thyroid gland 

Pars distalis, adenoma 

Pituitary gland 

Adenoma 

Islets, pancreatic 

Pheochromocytoma benign 

None 

General Body System 

Adenoma 

Preputial gland 

Genital System 
74 Methylphenidate Hydrochloride, NTP TR 439 

(continued) 

Summary of the Incidence of Neoplasms in Male Rats in the 2-Year Feed Study of Methylphenidate Hydrochloride 

TABLE A1 

0 PPm 100 PPm 500 PPm 1,Ooo PPm 

Testes 

Genital System (continued) 

15-Month Interim Evaluation (continued) 

(10) (10) (10) (10) 

Interstitial cell, adenoma 

Bilateral, interstitial cell, adenoma 7 (70%) 7 (70%) 

2 (20%) 

8 (80%) 8 (80%) 

2 (20%) 3 (30%) 

None 

Hematopoietic System 

None 

Integumentary System 

None 

Musculoskeletal System 

None 

Nervous System 

I 

Lung 

Respiratory System 

Alveolar/bronchiolar adenoma 

None 

Special Senses System 

None 

Urinary System 

2-Year Study 

Intestine large, cecum 

Intestine large, rectum 

Intestine large, colon 

Alimentary System 

Lipoma 

POW 

Liver 

Intestine small, ileum 

Intestine small, jejunum 

Intestine small, duodenum 

Histiocytic sarcoma 

Hepatocellular adenoma 

Mesentery 
Lesions in Male Rats 75 

(continued) 

Summary of the Incidence of Neoplasms in Male Rats in the 2-Year Feed Study of Methylphenidate Hydrochloride 

TABLE A1 

0 PPm 100 PPm 500 ppm 1,000 ppm 

Pancreas 

Alimentary System (continued) 

&Year Study (continued) 

Stomach, glandular 

Acinus, adenoma 

Heart 

Cardiovascular System 

Adrenal medulla 

Endocrine System 

Bilateral, pheochromocytoma benign 

Pheochromocytoma benign 

Pheochromocytoma malignant 

Carcinoma 

Adenoma 

Islets, pancreatic 

Adenoma 

Parathyroid gland 

Pars distalis, carcinoma 

Pars distalis, adenoma, multiple 

Pars distalis, adenoma 

Pituitary gland 

Follicular cell, carcinoma 

Follicular cell, adenoma 

C-cell, carcinoma 

C-cell, adenoma 

Bilateral, C-cell, adenoma 

Schwannoma malignant, metastatic, skin 

Thyroid gland 

(49) 

5 (10%) 

12 (24%) 

1 (2%) 

1 (2%) 

(49) 

4 (8%) 

1 (2%) 

1 (2%) 

(48) 

1 (2%) 

5 (10%) 

1 (2%) 

(50) 

2 (4%) 

(49) 

(46) 

10 (20%) 

(49) 

4 (8%) 

1 (2%) 

(49) 

5 (10%) 

1 (2%) 

(50) 

(50) 

1 (2%) 

6 (12%) 

1 (2%) 

2 (4%) 

10 (20%) 

(51) 

2 (4%) 

10 (20%) 

1 (2%) 

2 (4%) 

(51) 

(47) 

1 (2%) 

1 (2%) 

1 (2%) 

7 (14%) 

None 

General Body System 

Genital System 

Coagulating gland 

Preputial gland 

Epididymis 

Adenoma 

Carcinoma 

Adenoma 

Testes 

Seminal vesicle 

Prostate 

Interstitial cell. adenoma 

Bilateral, interstitial cell, adenoma 

(47) 

(49) 

2 (4%) 

1 (2%) 

(49) 

(50) 

(50) 

6 (12%) 

40 (82%) 
76 Methylphenidate Hydrochloride, NTP TR 439 

SummaQ' of the Incidence Of Neoplasms in Male Rats in the 2-Year Feed Study of Methylphenidate Hydrochloride 

TABLE A1 

(continued) 

0 PPm 100 ppm 500 ppm 1,000 ppm 

Bone marrow 

Blood 

Hematopoietic System 

%Year Study (continued) 

Pancreatic, histiocytic sarcoma 

Mediastinal, histiocytic Sarcoma 

Osteosarcoma, metastatic, bone 

Histiocytic sarcoma 

Histiocytic sarcoma 

Lymph node, mesenteric 

Histiocytic sarcoma 

Lymph node, mandibular 

Histiocytic sarcoma 

Hemangiosarcoma 

Spleen 

Histiocytic sarcoma 

Lymph node 

Thymus 

(49) 

(49) 

(47) 

Skin 

Mammary gland 

Integumentary System 

Fibroadenoma 

Subcutaneous tissue, schwannoma malignant 

Squamous cell papilloma 

Sarcoma 

Keratoacanthoma 

Fibrosarcoma 

Fibroma 

Basal cell adenoma 

1 (2%) 

(50) 

(36) 

(50) 

(37) 

2 (4%) 

2 (6%) 1 (3%) 

3 (6%) 

1 (2%) 

1 (2%) 

1 (2%) 

1 (2%) 

1 (2%) 1 (2%) 

4 (8%) 

(51) 

(44) 

2 (5%) 

3 (6%) 

1 (2%) 

Bone 

Musculoskeletal System 

Skeletal muscle 

Osteosarcoma 

Chordoma 

Brain 

Nervous System 

Lung 

Respiratory System 

(50) (50) (50) (51) 

Schwannoma malignant, metastatic, skin 

Histiocytic Sarcoma 

Alveolarlbronchiolar adenoma 1 (2%) 1 (2%) 

1 (2%) 

1 (2%) . Nose (50) (49) (49) (51) 

Polyp 

1 (2%) 

1 (2%) 

Squamous cell carcinoma 
Lesions in Male Rats 77 

(continued) 

Summary of the Incidence of Neoplasms in Male Rats in the 2-Year Feed Study of Methylphenidate Hydrochloride 

TABLE A1 

Ear 

Special Senses System 

%Year Study (continued) 

Zymbal's gland 

(3) 

Carcinoma 

Carcinoma, metastatic, pituitary gland 1 (33%) 

(1) 

1 (100%) 

Kidney 

Urinary System 

Renal tubule, adenoma 

Sarcoma 

Lipoma 

Papilloma 

Urinary bladder 

(48) 

1 (2%) 

Multiple organs' 

Systemic Lesions 

(50) (50) (50) (51) 

Mesothelioma malignant 

Leukemia mononuclear 

Histiocytic sarcoma 

2 (4%) 

23 (45%) 

1 (2%) 

29 (58%) 25 (50%) 

3 (6%) 

17 (34%) 

1 (2%) 

Total animals with primary neoplasmsd 

Neoplasm Summary 

2-Year study 

15-Month interim evaluation 

9-Month interim evaluation 

2-Year study 

15-Month interim evaluation 

9-Month interim evaluation 

2-Year study 

15-Month interim evaluation 

9-Month interim evaluation 

2-Year study 

15-Month interim evaluation 

9-Month interim evaluation 

2-Year study 

2-Year study 

2-Year study 

2-Year study 

Total primary neoplasms 

Total animals with benign neoplasms 

Total benign neoplasms 

Total metastatic neoplasms 

Total animals with metastatic neoplasms 

Total malignant neoplasms 

Total animals with malignant neoplasms 

46 

10 

1 

48 

9 

47 

10 

48 

8 

123 

13 

1 

124 

11 

112 

14 

109 

9 

46 

10 

1 

47 

10 

47 

8 

47 

9 

90 

13 

1 

87 

11 

80 

14 

76 

9 

32 28 30 

33 

27 

37 32 33 

1 

5 

4 1 

1 1 

a Number of animals examined micrasoopicaily at site and number of animals with neoplasm 

primary neoplasms: all neoplasms except metastatic neoplasms 

Number of animals with any tissue examined microscopically 

No neoplasms were observed at any other site in any animal at the 9-month interim evaluation. 
78 Methylphenidate Hydrochloride, NTP TR 439 

Individual Animal Tumor Pathology of Male Rats in the 2-Year Feed Study of Methylphenidate Hydrochloride: 0 ppm 

TABLE A2 

4194906422259527758157555 

0952456913333677799011333 

3345555566666666666777777 

1416053452383874916624457 

2300451560062456612411222 

0000000000000000000000000 

Number of Days on Study 

Carcass ID Number 

Intestine large, rectum 

Intestine large, colon 

Esophagus 

Alimentary System 

......................... 

+A++++++A+++++A++++++A+++ 

......................... 

Stomach, glandular 

Stomach, forestomach 

Salivary glands 

Pancreas * 

Mesentery 

Liver 

Intestine small, ileum 

Intestine small, jejunum 

Intestine small, duodenum 

Intestine large, cecum 

......................... 

+A++++++A+++++A++++++A+++ 

AA++++++A+++++A++++++A+++ 

AA++++++A++++++++++++A+++ 

+A++++++A+++++A++++++A+++ 

......................... 

++++++++A++++++++++++++++ 

......................... 

+A+++++++++++++++++++++++ 

++ 

Cardiovascular System 

Heart .......................... 

Adrenal medulla 

Adrenal cortex 

Endocrine System 

++++++++++++++M++++++++++ 

......................... 

+++++++'++++++M+++++++++++ 

......................... 

X 

+A+++++++++++++++++++M+++ 

Bilateral, pheochromocytoma benign 

Pheochromocytoma benign 

Pheochromocytoma malignant 

Islets, pancreatic 

Pituitary gland 

Parathyroid gland 

Adenoma 

xxx xx 

X 

Pars distalis, carcinoma 

Pars distalis, adenoma, multiple 

Pars distalis, adenoma 

Follicular cell, adenoma 

C-cell, carcinoma 

Ccell, adenoma 

x X X 

X 

Thyroid gland ......................... 

X 

General Body System 

None 

Genital System 

Preputial gland 

Epididymis 

Testes 

Seminal vesicle 

Prostate 

Adenoma 

......................... 

......................... 

........................... 

+++++++++++M++A++++++++++ 

+++++++++++M+++++++++++++ 

xx xxxxxxxxxxxxxxxxxx 

Interstitial cell, adenoma 

Bilateral, interstitial cell, adenoma, 

xx 

A: Autolysis precludes examination 

+: Tissue examined microscopically 

I: Insufficient tissue 

M Missing tissue 

Blank: Not examined 

X Lesion present 
Lesions in Male Rats . 79 

(continued) 

Individual Animal Tumor Pathology of Male Rats in the 2-Year Feed Study of Methylphenidate Hydrochloride: 0 ppm 

TABLE A2 

Number of Days on Study 

5555555555556666666666666 

3333333333333333333333333 

7777777777777777777777777 

0000000000000000~000000000 Total 

3333334555560011144466667' Tissues/ 

0267891036905805634512670 Tumors 

Carcass ID Number 

Intestine small, duodenum 

Intestine large, cecum 

Intestine large, rectum 

Intestine large, colon 

Esophagus 

Alimentary System 

......................... 50 

......................... 46 

......................... 48 

......................... 46 

......................... 46 

Stomach, glandular 

Stomach, forestomach 

Salivary glands 

Pancreas 

Mesentery 

Liver 

Intestine small, ileum 

Intestine small, jejunum 

......................... 50 

......................... 46 

.......................... 45 

......................... 48 

......................... 49 

......................... 50 

......................... 49 

+ ++ 5 

Cardiovascular System 

Heart ......................... 50 

Adrenal medulla 

Adrenal cortex 

Endocrine System 

......................... 50 

......................... 49 

Bilateral, pheochromocytoma benign 

Pheochromocytoma benign 

Pheochromocytoma malignant 

Islets, pancreatic 

Pituitary gland 

Parathyroid gland 

Adenoma 

Pars distalis, carcinoma 

Pars distalis, adenoma, multiple 

Pars distalis, adenoma 

Follicular cell, adenoma 

C-cell, carcinoma 

C-cell, adenoma 

Thyroid gland 

X 

1 

X 4 

......................... 50 

1 

1 

X X X X 10 

......................... 48 

+++++M+++++++++++++++++++ 48 

1 

......................... 49 

5 

xx x 12 

1 

x xx 

X xx X 

X 

xxx 

X 

xx X 

X 1 

General Body System 

None 

Genital System 

Preputial gland 

Epididymis 

Testes 

Seminal vesicle 

Prostate 

Adenoma 

Interstitial cell, adenoma 

Bilateral, interstitial cell, adenoma 

......................... 50 

......................... 50 

X 2 

......................... 49 

......................... 48 

......................... 50 

xxxxx xxxxxx xxxxxxxxxxxx 43 

X 3 

X 
80 

TABLE A2 

Methylphenidate Hydrochloride, NTP TR 439 

Individual Animal Tumor Pathology of Male Rats in the 2-Year Feed Study of Methylphenidate Hydrochloride: 0 ppm 

(continued) 

4194906422259527756157555 

0952456913333677799011333 

3345555566666666666777777 

Number of Days on Study 

0000~000000000000000000000 

Carcass ID Number 

1416053452383874916624457 

~3004515600624566124112~~ 

Hematopoietic System 

Lymph node 

Bone marrow ++++++++++++++M++/++++++++ 

+ + ++ + + ++ 

Spleen 

Lymph node, mesenteric 

Lymph node, mandibular 

Hemangiosarcoma 

Thymus 

......................... 

++M++++++++++++++++++++++ 

+M+++++++++++++++++++++++ 

++MM++++++++M+++++++M++++ 

X 

Fibroadenoma 

Mammary gland 

Integumentary System 

++++MM+M+M+M+++++++++M+M+ 

Skin 

Squamous cell papilloma 

Keratoacanthoma 

Fibrosarcoma 

Fibroma 

......................... X 

Musculoskeletal System 

Bone ++++++++++++++M++++++++++ 

Skeletal muscle + 

Nervous System 

Spinal cord 

Peripheral nerve 

Brain ......................... 

+ 

+ 

Respiratory System 

Trachea 

Nose 

Lung ......................... Alveolarbronchiolar adenoma 

......................... 

......................... 

Special Senses System 

Ear 

X 

++ 

Carcinoma, metastatic, pituitary 

gland 

Eye 

Urinary bladder 

Ureter 

Kidney 

Urinary System 

+A++++++A++M+AA++++A+A+++ 

X ......................... 

Sarcoma 

+ 

~ 

Systemic Lesions 

Multiple organs 

Mesothelioma malignant 

Leukemia mononuclear 

......................... 

X 

xx xxx xxxxxx x xxx 
Lesions in Male Rats 81 

(continued) 

Individual Animal Tumor Pathology of Male Rats in the 2-Year Feed Study of Methylphenidate Hydrochloride: 0 ppm 

TABLE A2 

5555555555556666666666666 

3333333333333333333333333 

7777777777777777777777777 

0000000000000000000000000 Total 

3333334555560011144466667 Tissues1 

0267891036905805634512670 Tumors 

~ ~~ ~~ 

Number of Days on Study 

Carcass ID Number 

Hematopoietic System 

Lymph node, mandibular 

Lymph node 

Bone marrow ......................... 49 

+ 11 

......................... 49 

++ 

Lymph node, mesenteric ......................... 49 

Spleen 

Hemangiosarcoma 

Thymus 

......................... 50 

X 2 

++++++++++M++M++MM++M++++ 41 

Fibroadenoma 

Mammary gland 

Integumentary System 

Squamous cell papilloma 

Keratoacanthoma 

Fibrosarcoma 

Fibroma 

Skin 

1 

1 

1 

1 

......................... 50 

1 

+++MM+++++M+++++++M++M+++ 38 

X 

X 

X 

X 

Musculoskeletal System 

Skeletal muscle 

Bone 

1 

......................... 49 

Nervous System 

Spinal cord 

Peripheral nerve 

Brain 

1 

1 

......................... 50 

Respiratory System 

Trachea 

Nose 

Lung 

......................... 50 

......................... 50 

1 

......................... 50 

Alveolarbronchiolar adenoma X 

Special Senses System 

Ear 

Carcinoma, metastatic, pituitary 

gland 

Eye + 

+ 3 

1 

1 

Urinary bladder 

Ureter 

Kidney 

Urinary System 

......................... 43 

1 

1 

......................... 49 

Sarcoma 

Systemic Lesions 

Multiple organs 

1 

X xxxxxx x x xx x xx 29 

......................... 50 

Mesothelioma malignant 

Leukemia mononuclear 
82 Methylphenidate Hydrochloride, NTP TR 439 

TABLE A2 

, Individual Animal Tumor Pathology of Male Rats in the 2-Year Feed Study of Methylphenidate Hydrochloride: 100 ppm 

3599376039005677444444444 

4102349023557781233333333 

0344555666666667777777777 

6453262172638598923703468 

1739223329929997077788888 

1010111110010000100000000 

Number of Days on Study 

Carcass ID Number 

Alimentary System 

Intestine large, cecum 

Intestine large, rectum 

Intestine large, colon 

Esophagus 

Liver 

Intestine small, ileum 

Intestine small, jejunum 

Intestine small, duodenum 

Stomach, forestomach 

Salivary glands 

Pharynx 

Pancreas 

Mesentery 

Lipoma 

Hepatocellular adenoma 

+AA++AA+++A++++A+++++++++ 

++A+++++++AA+++++++++++++ 

+AA++A++++A++++++++++++++ 

......................... 

......................... 

+AA++AA+++AA+++A+++++++++ 

+AA++A++++A++++++++++++++ 

++A++++++++++++++++++++++ 

X 

++ + 

......................... 

......................... + ......................... 

Stomach, glandular ......................... 

Cardiovascular System 

Heart 

~~ ~~ ~ 

......................... 

Endocrine System 

Adrenal medulla 

Adrenal cortex 

Bilateral, pheochromocytoma benign 

Pheochromocytoma benign 

Pheochromocytoma malignant 

Parathyroid gland 

Carcinoma 

Islets, pancreatic 

Thyroid gland 

Pituitary gland 

Follicular cell, carcinoma 

C-cell, adenoma 

Pars distalis, adenoma 

......................... 

+++++++++++A+++++++++++++ 

X 

X X 

+++++++++M+++++++++++++++ 

+I +M++++++++++++++++++++,+ 

......................... X 

X X xx X 

......................... X X 

X 

General Body System 

None 

Genital System 

Epididymis 

Testes 

Seminal vesicle 

Prostate 

Carcinoma 

Adenoma 

Preputial gland 

Interstitial cell, adenoma 

Bilateral, interstitial cell, adenoma 

+++++M+++++M+++M+++++++++ 

+++++++++++M+++++++++++++ 

+++++++++++M+++++++++++++ 

......................... 

......................... 

xx xxxxx X xxxxxxxxx 

X x xx 
Lesions in Male Rats 83 

(continued) 

Individual Animal Tumor Pathology of Male Rats in the 2-Year Feed Study of Methylphenidate Hydrochloride: 100 ppm 

TABLE A2 

4444444444455555555555555 

3333333333333333333333333 

7777777777777777777777777 

Number of Days on Study 

Carcass ID Number 

0011111111100011111111111 Total 

9900001111178822233333334 Tissues/ 

1414560247997945803467890 Tumors 

Intestine large, cecum 

Intestine large, rectum 

Intestine large, colon 

Esophagus 

Alimentary System 

Liver 

Intestine small, ileum 

Intestine small, jejunum 

Intestine small, duodenum 

Stomach, glandular 

Stomach, forestomach 

Salivary glands 

Pharynx 

Pancreas 

Mesentery 

Lipoma 

Hepatocellular adenoma 

......................... 44 

......................... 47 

......................... 46 

......................... 50 

......................... 50 

......................... 43 

......................... 46 

......................... 49 

1 

......................... 50 

......................... 50 

......................... 50 

1 

.......................... 50 

6 

X 2 

X 

+ + + 

Cardiovascular System 

Heart ......................... 50 

Adrenal medulla 

Adrenal cortex 

Endocrine System 

1 

X 4 

+++++++++++++M+++++++++++ 49 

10 

......................... 49 

+++++++++++++M+++++M+++++ 46 

2 

......................... 50 

1 

5 

1 

++++++M++++++++++++++++++ 48 

++++++M++++++++++++++++++ 49 

Bilateral, pheochromocytoma benign 

Pheochromocytoma benign 

Pheochromocytoma malignant 

Parathyroid gland 

Carcinoma 

Islets, pancreatic 

Thyroid gland 

Pituitary gland 

xx X 

X 

X 

Follicular cell, carcinoma 

Call, adenoma 

Pars distalis, adenoma 

X 

xx X xx 

General Body System 

None 

Genital System 

Epididymis 

Testes 

Seminal vesicle 

Prostate 

Carcinoma 

Adenoma 

Preputial gland 

Interstitial cell, adenoma 6 

Bilateral, interstitial cell, adenoma xxxxxxxxxxxxxxxxxxxxx xx 40 

......................... 49 

......................... 50 

......................... 50 

2 

1 

......................... 47 

......................... 49 

X 

xx 

xx 
84 Methylphenidate Hydrochloride, NTP TR 439 

0344555666666667777777777 

Number of Days on Study 

1010111110010000100000000 

3599376039005677444444444 

4102349023557781233333333 

Carcass ID Number 

6453262172638598923703468 

1739223329929997077788888 

Hematopoietic System 

Lymph node, mesenteric 

Lymph node, mandibular 

Lymph node 

Bone marrow 

Blood + 

......................... 

++++++++++++++++M++++++++ 

+ ++ ......................... + + ++ +++ + 

Spleen 

Thymus ++++++++M+++++++++++M++++ 

......................... 

Fibroadenoma 

Mammary gland 

Integumentary System 

Sarcoma 

Keratoacanthoma 

Fibroma 

Basal cell adenoma 

Skin 

+M++++M+MMMMMM+++++++++++ 

,/ X 

......................... 

A 

Musculoskeletal System 

Bone ......................... 

Nervous System 

Brain 

Respiratory System 

Trachea 

Nose 

Lung ......................... Alveolarbronchiolar adenoma X 

......................... 

+++++++++M+++++++++++++++ 

Special Senses System 

Eye M 

Kidney 

Urinary System 

Renal tubule, adenoma 

Urinary bladder +AA++AA+++AM+++++++++++++ 

......................... 

Systemic Lesions 

Multiple organs 

Leukemia mononuclear 

......................... X x xx xxx xxx x x 
Lesions in Male Rats 85 

(continued) 

Individual Animal Tumor Pathology of Male Rats in the 2-Year Feed Study of Methylphenidate Hydrochloride: 100 ppm 

TABLE A2 

7777777777777777777777777 

Number of Days on Study 

4444444444455555555555555 

3333333333333333333333333 

0011111111100011111111111 Total 

9900001111178822233333334 Tissues/ 

1414560247997945803467890 Tumors 

Carcass ID Number 

Hematopoietic System 

Thymus 

Spleen 

Lymph node, mesenteric 

Lymph node, mandibular 

Lymph node 

Bone marrow 

Blood 

+++++++++++++++++++M+++++ 47 

......................... 50 

......................... 50 

......................... 49 

++ 18 

......................... 50 

1 

++ +++ 

Fibroadenoma 

Mammary gland 

Integumentary System 

Sarcoma 

Keratoacanthoma 

Fibroma 

Basal cell adenoma 

Skin 

1 

3 

X 2 

......................... 50 

2 

M+M++++++M+++++++MM++++M+ 36 

X 

X 

X 

X X 

X 

1 

Musculoskeletal System 

Bone ......................... 50 

Nervous System 

Brain ......................... 50 

Respiratory System 

Lung ......................... 50 

Alveolarlbronchiolar adenoma 

......................... .50 

......................... 49 

1 

Trachea 

Nose 

Special Senses System 

Eye ++ + 3 ~~ ~~~ ~ 

Urinary bladder 

Kidney 

Urinary System 

_____~~ 

......................... 50 

X 1 

......................... 44 

Renal tubule, adenoma 

Systemic Lesions 

Multiple organs ......................... 50 

Leukemia mononuclear xxx x xx X xxxxxx 25 
86 Methylphenidate Hydrochloride, NTP TR 439 

Number of Days on Study 

5362648346710112000001111 

2804623577780022333333333 

3345566666667777777777777 

1396949000062858156792345 

556YO58589086667999994444 

1111211111211111111111111 

Carcass ID Number 

Esophagus 

Alimentary System 

......................... 

Intestine small, ileum 

Intestine small, jejunum 

Intestine small, duodenum 

Intestine large, cecum 

Intestine large, rectum 

Intestine large, colon 

A+AAAA+++++A+AA++++++++++ 

++AAAA+++++++AA++++++++++ 

++AAAA+++++++++++++++++++ 

A+AAAA+++++++A+++++++++++ 

.......................... 

++AAAA+++++++++++++++++++ 

Liver ......................... Mesothelioma malignant, metastatic 

Pancreas 

Mesentery 

Stomach, glandular 

Stomach, forestomach 

Salivaty glands 

Acinus, adenoma 

++ + ++ + + 

++++A++++++++++++++++++++ 

++++A++++++M+++++++++++++ 

......................... 

++++++ ++++++++++++++++++ 

Cardiovascular System 

Heart 

~ ~~~ 

......................... 

Adrenal medulla 

Adrenal cortex 

Endocrine System 

Pheochromocytoma benign 

Pheochromocytoma malignant 

Pituitary gland 

Parathyroid gland 

Islets, pancreatic 

Thyroid gland 

C-cell, adenoma 

Schwannoma malignant, metastatic, 

Pars distalis, adenoma 

Follicular cell, carcinoma 

C-cell, carcinoma 

skin 

++++++++++M++++++++++++++ 

++++++++++M++++++++++++++ 

X 

+++A++++++++++++++++++++M 

+++++++++++++++++++++M+++ 

......................... X 

X X ......................... 

X 

X A 

General Body System 

None 

Genital System 

Epididymis 

Testes 

Seminal vesicle 

Prostate 

Carcinoma 

Adenoma 

Preputial gland ......................... 

......................... 

X 

......................... 

+++++++++++++++M+++++++++ 

+++++++++++++++M+++++++++ 

xxxxxxxxxxxxxx xxxxxx 

Interstitial cell, adenoma 

Bilateral, interstitial cell, adenoma 

X X 
Lesions in Male Rats 87 

(continued) 

Individual Animal Tumor Pathology of Male Rats in the 2-Year Feed Study of Methylphenidate Hydrochloride: 500 ppm 

TABLE A2 

Number of Days on Study 

1111111111111111144444444 

3333333333333333333333333 

7777777777777777777777~77 

1111111111111122211111222 Total 

4445566777778900058888000 Tissues/ 

7895603023477467891235125 Tumors 

Carcass ID Number 

Intestine small, duodenum 

Intestine large, cecum 

Intestine large, rectum 

Intestine large, colon 

Esophagus 

Alimentary System .. 

.......................... '50 

......................... 46 

.......................... 48 

......................... 44 

......................... 46 

Liver 

Intestine small, ileum 

Intestine small, jejunum 

Pancreas 

Mesentery 

Stomach, glandular 

Stomach, forestomach 

Salivary glands 

Acinus, adenoma 

Mesothelioma malignant, 

......................... 50 

......................... 42 

......................... 44 

......................... 49 

+ + 14 

1 

X 2 

......................... 49 

......................... 50 

......................... 48 

metastatic X 

++ + ++ 

X 

Cardiovascular System 

Heart ......................... 50 

Adrenal medulla 

Adrenal cortex 

Endocrine System 

......................... 50 

xx 7 

......................... 48 

......................... 49 

......................... 50 

5 

1 

......................... 49 

......................... 49 

Pheochromocytoma benign 

Pheochromocytoma malignant 

X 

X 

X X 

Pituitary gland 

Parathyroid gland 

Islets, pancreatic 

Thyroid gland 

C-cell, adenoma 

Schwannoma malignant, metastatic, 

Pars distalis, adenoma 

Follicular cell, carcinoma 

C-cell, carcinoma 

X X X 

skin 

1 

2 

6 

1 

X 

X xx 

X 

xx 

General Body System 

None 

Genital System 

Epididymis 

Testes 

Seminal vesicle 

Prostate 

Carcinoma 

Adenoma 

Preputial gland 

Interstitial cell, adenoma 4 

Bilateral, interstitial cell, adenoma xxxxxxxxx xxxxxxxxxxxx .xx 43 

......................... 50 

......................... 49 

......................... 49 

X 4 

2 

......................... 50 

......................... 50 

X X 

X X 

X X 
88 Methylphenidate Hydrochloride, NTP TR 439 

TABLE A2 

(continued) 

Individual Animal Tumor Pathology of Male Rats in the 2-Year Feed Study of Methylphenidate Hydrochloride: 500 ppm 

5362648346710112000001111 

2804623577780022333333333 

3345566666667777777777777 

1396949000062858156792345 

5567058589086667999994444 

11.11211111211111111111111 

Number of Days on Study 

Carcass ID Number 

Hematopoietic System 

Lymph node 

Bone marrow ......................... Osteosarcoma, metastatic, bone X 

+ + +++ +++ 

Spleen 

Lymph node, mesenteric 

Lymph node, mandibular 

Thymus +++++++++++M+++++++++++++ 

......................... 

++MA+++++++++++++++++++++ 

+++M++M++++++++++++++++++ 

Fibroadenoma 

Mammary gland 

Integumentary System 

Subcutaneous tissue, schwannoma 

Squamous cell papilloma 

Sarcoma 

Keratoacanthoma 

Fibroma 

Skin 

+++++M++M+MMM+++M+M++++++ 

.......................... 

X xx 

X 

malignant X 

Musculoskeletal System 

Bone 

Skeletal muscle 

Osteosarcoma 

Chordoma 

......................... X 

+++ 

X 

+ 

Nervous System 

Spinal cord 

Peripheral nerve 

Brain ......................... , 

+ 

+ 

Respiratory System 

Lung ......................... 

Schwannoma malignant, metastatic, 

Mesothelioma malignant, metastatic X 

skin X 

Trachea 

Nose 

......................... 

++++++++++++++++++++++++M 

Carcinoma 

Zymbal's gland 

Special Senses System 

Urinary bladder 

Kidney 

Urinary System 

Eye + 

X 

+ 

A+AAAA++A++++++M+++++++++ 

......................... 

Systemic Lesions 

Multiple organs 

Mesothelioma malignant 

Leukemia mononuclear 

......................... xx xxxx xxx 

xx 
Lesions in Male Rats 89 

TABLE A2' 

(continued) 

Individual Animal Tumor Pathology of Male Rats in the 2-Year Feed Study of Methylphenidate Hydrochloride: 500 ppm 

1111111111111111144444444 

3333333333333333333333333 

~7777777177777177777777777 

Number of Days on Study 

Carcass ID Number 

1111111111111122211111222 Total 

4445566777778900058888000 Tissues/ 

7895603023417467891235125 Tumors 

Hematopoietic System 

Bone marrow 

Thymus 

Spleen 

Lymph node, mesenteric 

Lymph node, mandibular 

Lymph node 

++++++M++++++++++++++++M+ 41 

......................... 50 

......................... 48 

......................... 48 

+ 15 

1 

......................... 50 

Osteosarcoma, metastatic, bone 

++ + ++ + 

Fibroadenoma 

Mammary gland 

Integumentary System 

Subcutaneous tissue, schwannoma 

Squamous cell papilloma 

Sarcoma 

Keratoacanthoma 

Fibroma 

Skin 

1 

1 

4 

1 

......................... 50 

1 

++++++MM+M+++MM++++++++M+ 37 

1 

X 

X 

X 

X 

Musculoskeletal System 

malignant 

Bone 

1 

1 

......................... 50 

Skeletal muscle + 6 

Osteosarcoma 

Chordoma 

+ 

Nervous System 

Spinal cord 

Peripheral nerve 

Brain 

1 

1 

......................... 50 

Respiratory System 

Lung 

1 

......................... 50 

......................... 50 

......................... 49 

1 

Schwannoma malignant, metastatic, 

Mesothelioma malignant, metastatic 

skin 

Trachea 

Nose 

Carcinoma 

Zymbal's gland 

Special Senses System 

Urinary bladder 

Kidney 

Urinary System 

Eye + + 

1 

1 

3 

......................... 50 

......................... 43 

Systemic Lesions 

Multiple organs 

3 

x xx 17 

......................... 50 

Mesothelioma malignant 

Leukemia mononuclear 

X 

X xx xx 
90 Methylphenidate Hydrochloride, NTP TR 439 

Individual Animal Tumor Pathology of Male Rats in the 2-Year Feed Study of Methylphenidate Hydrochloride: 1,000 ppm 

TABLE A2 

0577698089358226299999999 

8885831993577888222222222 

1113345556666666777777777 

Number of Days on Study 

6771332693181857869893452 

4313121647144254511334445 

2222222222222222222222222 

Carcass ID Number 

Intestine large, rectum 

Intestine large, colon 

Esophagus 

Alimentary System 

~ Intestine large, cecum 

Polyp 

Liver 

Intestine small, ileum 

Intestine small, jejunum 

Intestine small, duodenum 

Pancreas 

Mesentery 

Histiocytic sarcoma 

Tongue 

Stomach, glandular 

Stomach, forestomach 

Salivary glands 

Acinus, adenoma 

AAA++AA+++++++++AA+++++++ 

++A++++++++++++++++++++++ 

+AA+++A++++++++++A+++++++ 

......................... 

......................... 

AAA+AA+++++++++++A+++++++ 

+AA+AA++++++++++A++++++++ 

+AA++A+++++++++++++++++++ 

X 

+ ++ + ......................... + 

......................... 

......................... 

......................... 

Cardiovascular System 

Heart .......................... 

Adrenal medulla 

Adrenal cortex 

Endocrine System 

Islets, pancreatic 

+++++++++++++++++++++++M+ 

+++++++++++++++++++++++M+ 

Pheochromocytoma benign xx ......................... 

Carcinoma 

Adenoma 

Pituitary gland 

Adenoma 

Parathyroid gland 

Pars distalis, adenoma 

Follicular cell, carcinoma 

C-cell, carcinoma 

Ccell, adenoma 

Bilateral, C-cell, adenoma 

Thyroid gland 

X 

M++++++++++++++++++++++++ 

++A++++++++++++++++++++++ 

......................... X xx 

X x xx 

General Body System 

None 

Genital System 

Coagulating gland 

Preputial gland 

Epididymis 

Adenoma 

Carcinoma 

Adenoma 

X 

+ 

......................... 

......................... 

X X 
Lesions in Male Rats 91 

(continued) 

Individual Animal Tumor Pathology of Male Rats in the 2-Year Feed Study of Methylphenidate Hydrochloride: 1,000 ppm 

TABLE A2 

99999999999900000000000000 

22222222222233333333333333 

77777777777777777777777777 

22222222222222222222222222 Total 

55666667778122223345556177 Tissues/ 

34123480790424592520690145 Tumors 

Number of Days on Study 

Carcass ID Number 

Intestine large, rectum 

Intestine large, colon 

Esophagus 

Alimentary System 

.......................... 51 

.......................... 47 

.......................... 50 

Intestine large, cecum 

Liver 

Intestine small, ileum 

Intestine small, jejunum 

Intestine small, duodenum 

Pancreas 

Mesentery . 

Histiocytic sarcoma 

Tongue 

Stomach, glandular 

Stomach, forestomach 

Salivary glands 

Acinus, adenoma 

Polyp 

+ 1 

.......................... 51 

.......................... 51 

.......................... 51 

1 

.......................... 51 

+ ++ ++ 14 

1 

.......................... 51 

.......................... 45 

.......................... 46 

.......................... 48 

1 

.......................... 44 

X 

+ + + + 

X 

Cardiovascular System 

Heart .......................... 51 

Adrenal medulla 

Adrenal cortex 

Endocrine System 

Islets, pancreatic 

1 

1 

7 

1 

.......................... 50 

X X X 10 

.......................... 51 

1 

+++M++++M+++M+++++++++++++ 47 

2 

2 

.......................... 51 

x xx 10 

.......................... 50 

.......................... 50 

Carcinoma 

Adenoma 

Pheochromocytoma benign 

Pituitary gland 

Adenoma 

Parathyroid gland 

Pars distalis, adenoma 

Follicular cell, carcinoma 

C-cell, carcinoma 

C-cell, adenoma 

Bilateral, C-cell, adenoma 

Thyroid gland 

X 

X X X xx 

X X 

X 

X 

xx xx 

X xx 

X 

X 

General Body System 

None 

Genital System 

Coagulating gland 

Preputial gland 

Epididymis 

Adenoma 

Carcinoma 

Adenoma 

2 

1 

.......................... 51 

.......................... 51 

1 

1 

X 
92 Methylphenidate Hydrochloride, .NTP TR 439 

TABLE A2 

(continued) 

Individual Animal Tumor Pathology of Male Rats in the 2-Year Feed Study of Methylphenidate Hydrochloride: 1,000 ppm 

0577698089358226299999999 

8885831993577888222222222 

1113345556666666777777777 

6771332693181857869893452 

4313121647144254511334445 

2222222222222222222222222 

Number of Days on Study 

Carcass ID Number 

Genital System (continued) 

Teites 

Seminal vesicle 

Prostate 

......................... 

......................... 

......................... 

xxxxx xxxxxxxxxxxxx 

Interstitial cell, adenoma 

Bilateral, interstitial cell, adenoma 

X X 

Hematopoietic System 

Bone marrow ......................... Histiocytic sarcoma X 

Lymph node 

Pancreatic, histiocytic sarcoma 

Mediastinal, histiocytic sarcoma 

Lymph node, mesenteric 

Histiocytic sarcoma 

Lymph node, mandibular 

Histiocytic sarcoma 

Histiocytic sarcoma 

Spleen 

Histiocytic sarcoma 

Thymus 

X 

X 

++ + + + 

X 

X 

X 

X 

++M++++++++M++'+++++++++++ 

......................... 

++A++++++++++++++++++++++ 

......................... 

Fibroadenoma 

Mammary gland 

Integumentary System 

Keratoacanthoma 

Fibroma 

Skin 

+MM+++++M+MM+++++++++++++ 

......................... X X X 

Musculoskeletal System 

Bone ......................... 

Nervous System 

Spinal cord 

Brain ......................... 

Respiratory System 

Lung ......................... 

Mesothelioma malignant, metastatic, 

Histiocytic sarcoma X 

heart X 

Nose ......................... Polyp 

Squamous cell carcinoma X 

Trachea ......................... 

Special Senses System 

Ear 

Eye + 
Lesions in Male Rats 93 

(continued) 

Individual Animal Tumor Pathology of Male Rats in the 2-Year Feed Study of Methylphenidate Hydrochloride: 1,000 ppm 

TABLE A2 

99999999999000000000000000 

22222222222333333333333333 

11111111111111111111111111 

Number of Days on Study 

Carcass ID Number 

22222222222222222222222222 Total 

55666661118122223345556111 Tissues/ 

34123480190424592520690145 Tumors 

Genital System (continued) 

Prostate .......................... 51 

Testes 

Seminal vesicle .......................... 51 

........................... 51 

Bilateral, interstitial cell, adenoma xxxxxxx xxxxxxxxxxxxxxxxxx 43 

Interstitial cell, adenoma X 3 

Hematopoietic System 

Lymph node 

Bone marrow 

.......................... 50 

1 

.......................... 51 

1 

1 

+ 11 

1 

.......................... 51 

Pancreatic, histiocytic sarcoma 

Mediastinal, histiocytic sarcoma 

Histiocytic sarcoma 

Lymph node, mesenteric 

Histiocytic sarcoma 

Lymph node, mandibular 

+++ + + 

~~ 

Histiocytic sarcoma 

Histiocytic sarcoma 

Histiocytic sarcoma 

Spleen 

Thymus 

1 

.......................... 49 

1 

.......................... 51 

1 

Fibroadenoma 

Mammary gland 

Integumentary System 

Keratoacanthoma 

Fibroma 

Skin 

X 1 

3 

.......................... 51 

2 

+++++++++++++++++M+++++M++ 44 

X X 

~~ 

Musculoskeletal System ~~ ~ 

Bone .......................... 51 

Nervous System 

~~ 

Spinal cord 

Brain 

1 

.......................... 51 

+ 

Respiratory System 

Lung 

1 

.......................... 51 

.......................... 51 

1 

1 

.......................... 51 

1 

Mesothelioma malignant, metastatic, 

Histiocytic sarcoma 

heart 

Nose 

Polyp X 

Squamous cell carcinoma 

Trachea 

Special Senses System 

Ear 

Eye 

+ 

3 

1 

++ 
94 Methylphenidate Hydrochloride, NTP TR 439 

(continued) 

Individual Animal Tumor Pathology of Male Rats in the 2-Year Feed Study of Methylphenidate Hydrochloride: 1,000 ppm 

TABLE A2 

Number of Days on Study 

0577698089358226299999999 

8885831993577888222222222 

1113345556666666777777777 

6771332693181857869893452' 

4313121647144254511334445 

2222222222222222222222222 

Carcass ID Number 

Urinary bladder 

Kidney 

Urinary System 

Papilloma 

Lipoma 

+AA+AAA+++++++++A++++++++ 

AAA++++++++++++++++++++++ 

X 

Systemic Lesions 

Multiple organs 

xxx xx xx xxxx 

......................... 

Mesothelioma malignant 

Leukemia mononuclear 

Histiocytic sarcoma X 

X X 
Lesions in Male Rats 95 

(continued) 

Individual Animal Tumor Pathology of Male Rats in the 2-Year Feed Study of Methylphenidate Hydrochloride: 1,000 ppm 

TABLE A2 

99999999999000000000000000 

22222222222333333333333333 

77777777777777777777777777 

22222222222222222222222222 Total 

55666667778122223345556777 Tissues/ 

34123480790424592520690145 Tumors 

Number of Days on Study 

Carcass ID Number 

Urinary bladder 

Kidney 

Urinary System 

1 

.......................... 45 

1 

.......................... 48 

Papilloma 

Lipoma 

X 

Systemic Lesions 

Multiple organs 

2 

X xx X xxxx X 23 

1 

.......................... 51 

Mesothelioma malignant 

Leukemia mononuclear 

Histiocytic sarcoma 
96 Methylphenidate Hydrochloride, NTP TR 439 

Statistical Analysis of Primary Neoplasms in Male Rats in the 2-Year Feed Study of Methylphenidate Hydrochloride 

TABLE A3 

0 PPm 100 ppm 500 ppm 1,000 ppm 

Fisher exact test 

Cochran-Armita e testd 

Logistic regression testsd 

Life table tests 

First incidence days 

Terminal rates' 

Adjusted ratesb 

overall ratesa 

Adrenal Medulla: Benign Pheochromocytoma 

50.8% 

17/49 (35%) 

P-0.177N 

P=0.151N 

P=O.l22N 

639 

12/28 (43%) 

% 

do 

P=0.005N 

P=O.O04N 

676 

5732 (16%) 

17.9% 

6/48 (13%) 

4/34 (12%) 

5/49 (10%) 

13.8% 

P=O.OOlN 

P=0.001N 

653 

P=0.049N 

P=O.O33N 

729 (T) 

10/33 (30%) 

30.3% 

lobo (20%) 

P=O.O09N P=0.003N P=0.078N 

Fisher exact test 

Cochran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

Adrenal Medulla: Benign or Malignant Pheochromocytoma -- 

P=O.llON 

P=O.O87N 

P=0.069N 

639 

13/28 (46%) 

53.9% 

18/49 (37%) 

P=0.006N 

P=0.004N 

676 

6/32 (19%) 

20.9 3 

7/48 (15%) 

4/34 (12%) 

5/49 (10%) 

13.8% 

P<0.001N 

P<0.001N 

653 

P=0.029N 

P=0.019N 

729 (T) 

10/33 (30%) 

3.370 

10/50 (20%) 

P=O.OllN P=O.002N P=O.O52N 

Fisher exact test 

Cochran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

Pancreatic Islets Adenoma or Carcinoma 

, 1/49 (2%) 

3.6% 

P=O.139 

P=O.134 

P=O.157 

729 (T) 

1/28 (4%) 

P=O.505 

P=O.543 

596 

1/33 (3%) 

5.2% 

2/50 (4%) 

e 

0.0% 

0/50 (0%) 

0/34 (0%) - 

P=0.461N 

P=0.461N 

11.4% 

4/51 (8%) 

P=O.204 

P=O.236 

686 

3/34 (9%) 

P=O.508 P=0.495N P=O.194 

Fisher exact test 

Cochran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

Pituitary Gland (Pars Distalis): Adenoma 

P=0.368N 

P=0.377N 

P=0.306N 

612 

8/28 (29%) 

34.4% 

11/48 (23%) 

21.2% 

7/48 (15%) 

P=0.142N 

P=O.l22N 

729 

7/33 (21%) 9/34 (26%) 

lO/5l (20%) 

28.3% 

P=O.406N 

P=0.327N 

675 

P=O.483N 

P=O.382N 

409 

6/33 (18%) 

25.9% 

10/49 (20%) 

P=0.479N P=0.217N P=0.437N 

Fisher exact test 

Cochran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

Pituitary Gland (Pars Distalis): Adenoma or Carcinoma 

P=O.302N 

P=0.313N 

P=0.248N 

566 

8/28 (29%) 

35.9% 

12/48 (25%) 

P=0.114N 

P=0.083N 

729 (T) 

7/33 (21%) 

21.2% 

7/48 (15%) 

P=0.341N 

P=0.250N 

675 

9/34 (26%) 

28.3% 

10/51 (20%) 

P=0.387N 

P=0.301N 

409 

6/33 (18%) 

25.9% 

10149 (20%) 

P=0.383N P-0.153N P=0.343N 
Lesions in Male Rats 97 

(continued) 

Statistical Analysis of Primary Neoplasms in Male Rats in the 2-Year Feed Study of Methylphenidate Hydrochloride 

TABLE A3 

0 PPm 100 ppm 500 ppm 1,000 ppm 

Fisher exact test 

Cochran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

Preputial Gland: Carcinoma 

Fisher exact test 

Cochran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

Preputial Gland: Adenoma or Carcinoma 

Fisher exact test 

Cochran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

Skin: Fibroma 

Fisher exact test 

Cochran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

Skin: Keratoacanthoma 

0128 (0%) 

0/50 (0%) 

0.0% 

- 

P=O.265 

P=O.275 

P=O.297 

7.1% 

2/50 (4%) 

729 (T) 

2/28 (7%) 

P=O.405 

P=O.434 

P=O.456 

2.1 % 

1/50 (2%) 

P=O.383 

P=O.379 

P=O.420 

524 

0/28 (0%) 

729 (T) 

1/28 (4%) 

1/50 (2%) 

3.6% 

P=O.489 

P=O.503 

P=O.536 

2/33 (6%) 

6.1% 

2/47 (4%) 

P=O.275 

P=O.275 

729 (T) 

P=O.232 

9.1% 

3/47 (6%) 

729 (T) 

3/33 (9%) 

P=O.575 

P=O.575 

P=O.470 

9.1% 

3/50 (6%) 

P=O.305 

P=O.349 

729 (T) 

3/33 (9%) 

P=O.309 

P=0.725N 

P=0.725N 

729 (T) 

1/33 (3%) 

3.0% 

1/50 (2%) 

P=0.753N 

Fisher exact test 

Cochran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

Skin: Squamous Cell Papilloma, Keratoacanthoma, or Basal Cell Adenoma 

729 (9 

2/28 (7%) 3/33 (9%) 

2/50 (4%) 

9.1% 

3/50 (6%) 

7.1% 

P=0.347N 

P=0.321N P=O.575 

P=0.294N P=O.575 

729 (T) 

P=O.500 

11.8% 

4/50 (8%) 

729 (TI 

4/34 (12%) 

P=O.O59 

P=O.O89 

P=O.O89 

6/34 (18%) 

17.6% 

6/50 (12%) 

P=O.134 

P=O.200 

P=O.200 

729 (T) 

2.9% 

1/50 (2%) 

729 (T) 

1/34 (3%) 

P=O.753N 

P=O.750 

P=0.739N 

10.9% 

4/50 (8%) 

P=O.206 

P=O.240 

653 

P=O.181 

3/34 (9%) 

10.9% 

4/50 (8%) 

P=O.386 

P=O.426 

653 

P=O.339 

3/34 (9%) 

P=O.241 

P=O.280 

675 

OB4 (0%) 

5.3% 

2/51 (4%) 

P=O.252 

P=O.531 

P=O.584 

675 

1/34 (3%) 

8.1% 

3/51 (6%) 

P=O.509 

P=O.316 

P=O.346 

639 

2/34 (6%) 

8.1% 

3/51 (6%) 

P=O.316 

729 (T) 

1/34 (3%) 

1/51 (2%) 

2.9% 

P=O.718N 

P=0.718N 

P=0.748N 

1/34 (3%) 

1/51 (2%) 

2.9% 

P=0.432N 

P=0.432N 

729 (T) 

P=0.492N 
98 Methylphenidate Hydrochloride, NTP TR 439 

(continued) 

Statistical Analysis of Primary Neoplasms in Male Rats in the 2-Year Feed Study of Methylphenidate Hydrochloride 

TABLE A3 

0 PPm 100 ppm 500 ppm 1,000 ppm 

Fisher exact test 

Cochran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

Testes: Adenoma 

P=0.372N 

P=O.336 P=O.336 P=O.586 P=O.375 

P=0.167N P=0.206N P=0.153N P=0.146N 

459 429 542 439 

27/28 (96%) 

97.9% 100.0% 100.0% 100.0% 

46/50 (92%) 46/49(94%) 47/50 (94%) 46/51 (90%) 

P=O.511 P=O.500 P=0.513N 

33/33 (100%) 34/34 (100%) 34/34 (100%) 

Fisher exact test 

Cochran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

Thyroid Gland (C-cell): Adenoma 

Fisher exact test 

Cochran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

Thyroid Gland (C-cell): Adenoma or Carcinoma 

Fisher exact test 

Cochran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

All Organs: Mononuclear Cell Leukemia 

Fisher exact test 

Cochran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

All Organs: Malignant Mesothelioma 

4/28 (14%) 3/32 (9%) 

14.3% 11.5% 16.9% 22.5% 

4/50 (8%) 4/49 (8%) 6/50 (12%) 8/50 (16%) 

P=O.O92 

P=O.106 P=0.634N P=O.472 P=O.222 

P=O.139 P=0.577N P=O.494 P=O.277 

600 681 639 

P=O.631 P=O.370 P=O.178 

5/34 (15%) 7/34 (21%) 

729 (T> 

5/50 (10%) 

5/28 (18%) 3/32 (9%) 6/34 (18%) 8/34 (24%) 

17.9% 11.5% 19.8% 25.4% 

4/49 (8%) 7/50 (14%) 9/50 (18%) 

P=O.O78 

P=O.O93 P=0.484N P=O.499 P=O.250 

P=O.124 P=0.424N P=O.519 P=O.308 

600 681 639 

P=0.513N P=O.380 P=O.194 

729 (T> 

P=0.097N 

P=0.176N P=0.263N P=0.016N P=0.286N 

P=0.060N P=0.149N P=0.006N P=0.069N 

549 533 638 518 

16/28 (57%) 17/33 (52%) 11/34 (32%) 16/34 (47%) 

69.9% 60.6% 41.7% 55.7% 

29/50 (58%) 25/50 (50%) 17/50 (34%) 23/51 (45%) 

P=O.274N P=O.O13N P=0.136N 

0/28 (0%) 0/33 (0%) 

0.0% 8.3% 5.1% 

1/50 (2%) 0/50 (0%) 3/50 (6%) 

P=0.493N P=O.315 P=O.511 

P=0.500N P=O.369 P=O.525 

701 653 

P=0.500N P=O.309 P=O.508 

1/34 (3%) 0/34 (0%) 

2/51 (4%) 

2.4% 

P=O.191 

P=O.188 

P=O.214 

632 - 
Lesions in Male Rats 99 

(continued) 

Statistical Analysis of Primary Neoplasms in Male Rats in the 2-Year Feed Study of Methylphenidate Hydrochloride 

TABLE A3 

0 PPm 100 PPm 500 PPm 1,m PPm 

Fisher exact test 

Cochran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

All Organs: Benign Neoplasms 

Fisher exact test 

Cochran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

All Organs: Malignant Neoplasms 

Fisher exact test 

Cochran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

All Organs: Benign or Malignant Neoplasms 

47/50 (94%) 47/50 (94%) 47/50 (94%) 46/51 (90%) 

100.0% 100.0% 100.0% 100.0% 

P=O.262N 

P=O.527 P=O.548 P=0.829N P=O.535 

P=0.114N P-O.202N P=O.l09N P=O.l02N 

459 409 542 

P=0.661N P=0.661N P=0.369N 

28/28 (100%) 33/33 (100%) 34/34 (100%) 34/34 (100%) 

P=0.414N 

P=O.392 

P=0.265N 

549 

17/28 (61%) 

73.7% 

3Y50 (64%) 28/50 (56%) 27/50 (54%) 30/51 (59%) 

64.8% 59.8% 66.6% 

18/33 (55%) 16/34 (47%) 19/34 (56%) 

533 406 439 

P=O.l53N P=O.O86N P=O.2OON 

P=0.420N P=0.321N P=O.456 

P=O.UON P=O.208N P=0.371N 

48/50 (96%) 47/50 (94%) 48/50 (96%) 46/51 (90%) 

100.0% 100.0%- lOO,O% 100.0% 

P=0.180N 

P=0.603N P=0.729N P=O.785 PtO.785 

P=0.100N P=0.160N P=0.115N P=0.077N 

459 409 406 439 

P=O.S00N P=0.691N P=0.226N 

28/28 (100%) 33/33 (100%) 34/34 (100%) 34/34 (100%) 

a Number of neoplasm-bearing animals/number of animals examined. Denominator is number of animals examined microscopically for adrenal gland, 

OTerminal sacrifice 

exact tests compare directly the overall incidence rates. For all tests, a negative trend or a lower incidence in an exposure group is indicated by N. 

as being (directly or indirectly) the cause of death. The logistic regression test regards these lesions as nonfatal. The Cochran-Armitage and Fisher 

to pairwise comparisons between the controls and that exposed group. The life table test regards neoplasms in animals dying prior to terminal kill 

Beneath the control incidence are the P values associated with the trend test. Beneath the exposed group incidence are the P values corresponding 

Observed incidence at terminal kill 

Kaplan-Meier estimated neoplasm incidence at the end of the study after adjustment for intercurrent mortality 

pancreatic islets, pituitay gland, preputial gland, testes, and thyroid gland; for other tissues, denominator is number of animals necropsied. 

e Not applicable; no neoplasms in animal group 
100 Methylphenidate Hydrochloride, NTP TR 439 

Historical Incidence of Adrenal Medulla PheochromocytomFs in Untreated Male F344/N Rats’ 

TABLE A4 

Study 

Malignant 

Incidence in Controls 

Benign 

Malignant 

Benign or 

Historical Incidence at TSI Mason Research Institute 

Turmeric oleoresin 

Quercetin 

Pentaerythritol tetranitrate 

HC Yellow 4 

Acetaminophen 

l-Amino-2,4-dibromoanthraquinone 

14/47 

12/50 

19/49 

19/50 

16/44 

12/50 

0147 

1/50 

0149 

2/50 

1/44 

1/50 

14/47 

13/50 

19/49 

19/50 

17/44 

13/50 

Overall Historical Incidence 

Range 

Standard deviation 

Total 

10%-63% 

11.6% 

414/1,234 (33.5%) 48/1,234 (3.9%) . 445/1,234b (36.1%) 

0%-20% 

4.8% 

14%-63% 

11.0% 

’ Data as of 20 August 1992 

Includes three complex pheochromocytomas 
Lesions in Male Rats 101 

of Methylphenidate Hydrochloride' 

Summary of the Incidence of Nonneoplastic Lesions in Male Rats in the 2-Year Feed Study 

TABLE A5 

Early deaths 

IS-Month interim CvrrlLotion 

PMoplrhinpJimt?ldUfh 

Animals initially in study 

Disposition Summary 

Natural deaths 

Moribund 

Accidental deaths 

Terminal sacrifice 

Died last week of study 

Suwivors 

10 

10 

70 

10 

10 

70 

10 

10 

70 

10 

9 

70 

7 

9 

1 

8 

14 

9 

7 

8 

9 

33 

1 

28 33 

70 

34 

Animals examined microscopically 70 70 70 

9-Month Interim Evaluation 

Parasite metazoan 

Intestine large, cecum 

Parasite metazoan 

Intestine large, rectum 

Parasite metazoan 

Intestine large, colon 

Alimentary System 

Bile duct, hyperplasia 

Hepatodiaphragmatic nodule 

Developmental malformation 

Liver 

Acinus, atrophy 

Inflammation, chronic, focal 

Fat, necrosis 

Pancreas 

Mesentely 

(9) 

(9) 

(9) 

(9) 

3 (33%) 

1 (11%) 

3 (33%) 

1 (11%) 

1 (11%) 

1 (10%) 

(8) 

2 (25%) 

1 (13%) 

3 (30%) 

Heart 

Cardiovascular System 

Atrium, dilatation 

Inflammation, chronic, focal 

Cardiomyopathy 

(10) (10) (10) (9) 

2 (20%) 

6 (60%) 2 (m) 4 (46%) 

1 (11%) 

3 (33%) 

4 (44%) 

6 (60%) 5 (5&%) 

Endocrine System 

Pars distalis, hyperplasia, focal 

Pars distalis, cyst 

Pituitary gland (9) 

1 (11%) 

1 (10%) 1 (10%) 3 (30%) 3 (33%) 

None 

General Body System 

a Number of animals examined microscopically at site and number of animals with lesion 
102 Methylphenidate Hydrochloride, NTP TR 439 

of Methylphenidate Hydrochloride (continued) 

Summary of the Incidence of Nonneoplastic Lesions in Male Rats in the 2-Year Feed Study 

TABLE A5 

0 PPm 100 ppm 500 ppm 1,000 ppm 

Preputial gland 

Genital System 

9-Month Interim Evaluation (continued) 

Inflammation, chronic, focal 

Abscess 

Seminiferous tubule, atrophy 

Interstitial cell, hyperplasia 

Bilateral, interstitial cell, hyperplasia 

(10) (10) (10) (9) 

1 (10%) 

8 (80%) 

1 (10%) 

8 (80%) 

1 (10%) 

1 (10%) 

1 (10%) 

1 (10%) 2 (20%) 

8 (80%) 

1 (11%) 

3 (33%) 

9 (100%) 

Testes (10) (10) (10) (9) 

Hematopoietic System 

Lymph node, mesenteric 

Lymph node 

Bone marrow 

Congestion 

Mediastinal, congestion 

Hyperplasia 

Depletion lymphoid 

Giant cell 

Thymus 

None 

Integumentary System 

None 

Musculoskeletal System 

None 

Nervous System 

Lung 

Respiratory System 

(10) (10) (10) (9) 

Peribronchial, inflammation, chronic ' ' 

Hyperplasia, adenomatous 

Metaplasia, squamous 

Inflammation, chronic, focal 

Inflammation, acute -. . ... -- 

10 (100%) 10 (100%) 

1 (10%) 

9 (90%) 

1 (11%) 

1 (11%) 

9 (100%) 

Nose - ., (10) ' (10) (10) (9) . -. .. 

1 (10%) 

10 (100%) 10 (100%) 10 (100%) 7 (78%) 

4 .(40%) 

None 

Special Senses System 
Lesions in Male Rats 103 

of Methylphenidate Hydrochloride (continued) 

Summary of the Incidence of Nonneoplastic Lesions in Male Rats in the 2-Year Feed Study 

TABLE A5 

0 PPm 100 ppm 500 PPm 1,000 ppm 

Kidney 

Urinary System 

9-Month Interim Evaluation (continued) 

Calculus microscopic observation only 

Urinary bladder 

Renal tubule, regeneration 

Nephropathy 

(10) (10) (10) (9) 

3 (30%) 3 (30%) 

6 (60%) 

4 (40%) 

1 (11%) 

2 (22%) 

5 (50%) 4 (40%) 

(10) (10) (10) (9) 

4 (40%) 1 (10%) 2 (20%) 

15-Month Interim Evaluation 

Intestine small, ileum 

Parasite metazoan 

Intestine large, cecum 

Parasite metazoan 

Intestine large, rectum 

Parasite metazoan 

Intestine large, colon 

Alimentary System 

Peyer’s patch, hyperplasia 

Bile duct, hyperplasia 

Hepatodiaphragmatic nodule 

Granuloma 

Fatty change 

Basophilic focus 

Liver 

Acinus, atrophy 

Fat, necrosis 

Pancreas 

Mesentery 

6 (60%) 

(10) 

3 (30%) 

(10) 

(10) 

4 (40%) 

7 (70%) 

1 (lO./o) 

1 (10%) 

(10) 

(1) 

1 (100%) 

6 (60%) 

3 (30%) 4 (40%) 

Heart 

Cardiovascular System 

Cardiomyopathy 

Endocrine System 

Pituitary gland 

Adrenal medulla 

Adrenal cortex 

Pars distalis, hyperplasia, focal 

Hyperplasia, focal 

Cytoplasmic alteration 

C-cell, hyperplasia 

Pars intermedia, cyst 

Pars distalis, inflammation, chronic, focal 

Thyroid gland 

None 

General Body System 
104 Methylphenidate Hydrochloride, NTP TR 439 

of Methylphenidate Hydrochloride (continued) 

Summary of the Incidence of Nonneoplastic Lesions in Male Rats in the 2-Year Feed Study 

TABLE A5 

0 PPm 100 ppm 500 PPm 1,000 ppm 

Preputial gland 

Genital System 

15-ikfOnth Interim Evaluation (continued) 

Inflammation, acute 

Inflammation, chronic 

Abscess 

Atrophy 

Seminal vesicle 

Inflammation, focal 

Inflammation, chronic 

Seminiferous tubule, atrophy 

Bilateral, interstitial cell, hyperplasia 

Testes 

Cyst 

Prostate 

10 (100%) 

(10) 

1 (10%) 

(10) 

8 (80%) 

1 (10%) 

2 (20%) 

(10) 

Hematopoietic System 

Thymus 

Spleen 

Lymph node, mandibular 

Lymph node 

Bone marrow 

Hyperplasia, lymphoid 

Depletion lymphoid 

Congestion 

Mediastinal, congestion 

Hyperplasia 

Skin 

Integumentary System 

Ulcer 

None 

Musculoskeletal System 

None 

Nervous System 

N0.W 

Respiratory System 

Inflammation, chronic 

Inflammation, acute 

Fungus 

(10) (10) (10) (10) 

8 (80%) 

2 (20%) 

2 (20%) 

4 (40%) 

4 (40%) 

6 (60%) 10 (100%) 9 (90%) 

1 (10%) 

1 (10%) 
Lesions in Male Rats 105 

of Methylphenidate Hydrochloride (continued) 

Summary of the Incidence of Nonneoplastic Lesions in Male Rats in the 2-Year Feed Study 

TABLE A5 

0 PPm 100 PPm 500 PPm 1,000 ppm 

None 

Special Senses System 

15-Month Interim Evaluation (continued) 

Inflammation, chronic, focal 

Urinary bladder 

Nephropathy 

Kidney 

Urinary System 

2-Year Study 

Intestine large, cecum 

Parasite metazoan 

Intestine large, rectum 

Parasite metazoan 

Intestine large, colon 

Alimentary System 

Parasite metazoan 

Hyperplasia, lymphoid 

Edema 

Autolysis 

Intestine small, ileum 

Hyperplasia, lymphoid 

Intestine small, jejunum 

Cyst 

Clear cell focus 

Basophilic focus 

Atrophy 

Angiectasis, focal 

Liver 

Lymphatic, angiectasis, focal 

Bile duct, hyperplasia 

Bile duct, dilatation 

Thrombosis 

Proliferation 

Necrosis, focal 

Mixed cell focus 

Infarct 

Hepatodiaphragmatic nodule 

Granuloma 

Fibrosis, focal 

Fatty change 

Eosinophilic focus 

Developmental malformation 

(46) 

(48) 

(46) 

5 (11%) 

4 (8%) 

1 (2%) 

2 (4%) 

2 (4%) 

(50) 

(46) 

(45) 

2 (4%) 

35 (70%) 

2 (4%) 

2 (4%) 

2 (4%) 

10 (20%) 

2 (4%) 

1 (2%) 

9 (18%) 

3 (6%) 

1 (2%) 

18 (36%) 

2 (4%) 

(44) 

(47) 

(46) 

8 (17%) 

9 (19%) 

1 (2%) 

2 (5%) 

1 (2%) 

(50) 

(43) 

(46) 

8 (16%) 

42 (84%) 

7 (14%) 

1 (2%) 

5 (10%) 

1 (2%) 

1 (2%) 

1 (2%) 

1 (2%) 

1 (2%) 

2 (4%) 

1 (2%) 

1 (2%) 

1 (2%) 

23 (46%) 

(44) 

(48) 

(46) 

9 (19%) 

9 (20%) 

1 (2%) 

(50) 

(42) 

(44) 

14 (28%) 

38 (76%) 

3 (6%) 

2 (4%) 

3 (6%) 

3 (6%) 

3 (6%) 

3 (6%) 

1 (2%) 

1 (2%) 

1 (2%) 

1 (2%) 

4 (8%) 

14 (28%) 

(44) 

(50) 

(47) 

5 (11%) 

6 (12%) 

1 (2%) 

1 (2%) 

(51) 

(45) 

(46) 

37 (73%) 

5 (10%) 

1 (2%) 

6 (12%) 

6 (12%) 

4 (8%) 

4 (8%) 

1 (2%) 

3 (670) 

1 (2%) 

1 (2%) 

3 (6%) 

18 (35%) 
106 Methylphenidate Hydrochloride, NTP TR 439 

of Methylphenidate Hydrochloride (continued) 

Summary of the Incidence of Nonneoplastic Lesions in Male Rats in the 2-Year Feed Study 

TABLE A5 

0 PPm 100 PPm 500 ppm 1,000 ppm 

&Year Sttldy (continued) 

Mesentery 

Alimentary System (continued) 

Accessory spleen 

Fat, necrosis 

Fat, hemorrhage 

Artery, thrombosis 

Artery, inflammation, chronic 

Fibrosis 

Vein, thrombosis 

Artery, inflammation, chronic 

Artery, hypertrophy 

Acinus, hyperplasia, focal 

Acinus, atrophy 

Pigmentation, focal 

Autolysis, focal 

Angiectasis 

Palate, inflammation, chronic 

Pharynv 

Thrombosis 

Hyperplasia 

Atrophy 

Salivary glands 

Ulcer 

Inflammation, chronic, focal 

Hyperkeratosis 

Cyst epithelial inclusion 

Stomach, forestomach 

Submucosa, fibrosis 

Mucosa, inflammation, acute 

Ulcer 

Hyperplasia, lymphoid 

Erosion 

Hyperkeratosis, focal 

Cyst 

Pancreas 

Stomach, glandular 

Tongue 

(5) 

1 (20%) 

1 (20%) 

2 (40%) 

(49) 

1 (2%) 

(50) 

1 (2%) 

1 (2%) 

(49) 

1 (2%) 

4 (8%) 

8 (17%) 

3 (6%) 

(48) 

1 (2%) 

21 (42%) 

2 (4%) 

1 (2%) 

(50) 

(1) 

1 (2%) 

1 (2%) 

1 (100%) 

(50) 

2 (4%) 

5 (10%) 

1 (2%) 

1 (2%) 

(50) 

(14) 

1 (7%) 

1 (7%) 

1 (7%) 

10 (71%) 

(49) 

2 (4%) 

1 (2%) 

1 (2%) 

16 (33%) 

(49) 

(50) 

1 (2%) 

(48) 

3 (6%) 

2 (4%) 

(14) 

1 (7%) 

1 (7%) 

1 (7%) 

1 (7%) 

11 (79%) 

(51) 

1 (2%) 

17 (33%) 

1 (2%) 

(51) 

3 (6%) 

1 (2%) 

1 (2%) 

(1) 

1 (100%) 

Heart 

Cardiovascular System 

Ventricle, dilatation 

Atrium, thrombosis 

Atrium, dilatation 

Artery, inflammation, chronic 

Mineralization 

Hypertrophy 

Cardiomyopathy 

(50) (50) 

4 (8%) 

42 (84%) 39 (78%) 

1 (2%) 

1 (2%) 

1 (2%) 

1 (2%) 

1 (2%) 

6 (12%) 

(50) (51) 

1 (2%) 

1 (2%) 

37 (74%) 35 (69%) 

1 (2%) 

1 (2%) 

1 (2%) 

1 (2%) 

1 (2%) 

3 (6%) 
Lesions in Male Rats 107 

of Methylphenidate Hydrochloride (continued) 

Summary of the Incidence of Nonneoplastic Lesions in Male Rats in the 2-Year Feed Study 

TABLE A5 

0 PPm 100 ppm 500 PPm 1,000 ppm 

&Year Study (continued) 

Endocrine System 

Vacuolization cytoplasmic 

Hypertrophy 

Hyperplasia, focal 

Hyperplasia 

Cytoplasmic alteration, focal 

Adrenal cortex 

Hyperplasia, focal 

Hemorrhage 

Adrenal medulla 

Parathyroid gland 

Hyperplasia 

Islets, pancreatic 

Hyperplasia, focal 

Ectopic thymus 

Pars intermedia, hyperplasia, focal 

Pars intermedia, cyst 

Pars distalis, hyperplasia, focal 

Pars distalis, hemorrhage 

Pars distalis, cyst 

Pars distalis, angiectasis 

Follicle, cyst 

C-cell, hyperplasia 

Ultimobranchial cyst 

Pituitary gland 

Thyroid gland 

(50) 

2 (4%) 

1 (2%) 

3 (6%) 

(49) 

1 (2%) 

4 (8%) 

16 (33%) 

(48) 

(49) 

1 (2%) 

1 (2%) 

2 (4%) 

1 (2%) 

(48) 

6 (13%) 

4 (8%) 

(49) 

4 (8%) 

1 (2%) 

2 (4%) 

1 (2%) 

(48) 

12 (25%) 

1 (2%) 

2 (4%) 

1 (2%) 

(46) 

(50) 

9 (18%) 

(49) 

3 (6%) 

(49) 

2 (4%) 

1 (2%) 

6 (12%) 

1 (2%) 

(49) 

16 (33%) 

(49) 

(50) 

1 (2%) 

1 (2%) 

(48) 

1 (2%) 

8 (17%) 

3 (6%) 

(50) 

8 (16%) 

1 (2%) 

(50) 

2 (4%) 

(47) 

(51) 

1 (2%) 

1 (2%) 

1 (2%) 

1 (2%) 

9 (18%) 

(50) 

6 (12%) 

None 

General Body System 

Atrophy 

Epididymis 

Genital System 

Spermatocele 

Fibrosis 

Dilatation 

Depletion cellular 

Abscess 

Preputial gland 

Metaplasia, squamous 

Inflammation, chronic 

Inflammation, acute 

Hyperplasia 

Ectasia 

Cyst 

(50) 

2 (4%) 

(50) 

4 (8%) 

6 (12%) 

1 (2%) 

5 (10%) 

7 (14%) 

(49) 

2 (4%) 

(47) 

2 (4%) 

4 (9%) 

1 (2%) 

5 (11%) 

3 (6%) 

(50) 

2 (4%) 

1 (2%) 

(50) 

2 (4%) 

1 (2%) 

1 (2%) 

1 (2%) 

(51) 

1 (2%) 

1 (2%) 

1 (2%) 

6 (12%) 

(51) 

2 (4%) 

3 (6%) 

3 (6%) 

1 (2%) 

5 (10%) 
108 Methylphenidate Hydrochloride, NTP TR 439 

of Methylphenidate Hydrochloride (continued) 

Summary of the Incidence of Nonneoplastic Lesions in Male Rats in the 2-Year Feed Study 

TABLE A5 

Prostate 

Genital System (continued) 

2-Year Study (continued) 

Inflammation, chronic 

Inflammation, acute 

Hyperplasia, focal 

Dilatation 

Congestion 

Atrophy 

Seminal vesicle 

Hemorrhage, focal 

Dilatation 

Atrophy 

Seminiferous tubule, atrophy 

Interstitial cell, hyperplasia 

Bilateral, interstitial cell, hyperplasia 

Cyst 

Testes 

(49) 

18 (37%) 

(50) 

1 (2%) 

11 (22%) 

(50) 

3 (6%) 

36 (72%) 

(49) 

1 (2%) 

4 (8%) 

4 (8%) 

(49) 

1 (2%) 

1 (2%) 

12 (24%) 

1 (2%) 

(49) 

37 (76%) 

2 (4%) 

1 (2%) 

(50) 

(51) 

18 (35%) 

1 (2%) 

1 (2%) 

(51) 

41 (80%) 

2 (4%) 

(51) 

2 (4%) 

1 (2%) 

Hematopoietic System 

Myelofibrosis 

Hyperplasia 

Granuloma 

Bone marrow 

Renal, lymphatic, angiectasis 

Renal, pigmentation 

Pancreatic, lymphatic, angiectasis 

Pancreatic, hyperplasia, lymphoid 

Mediastinal, lymphatic, angiectasis 

Mediastinal, pigmentation 

Mediastinal, granuloma 

Lumbar, lymphatic, angiectasis 

Inguinal, lymphatic, angiectasis 

Lymphatic, angiectasls 

Infiltration cellular lasma cell 

Depletion lymphoid 

Congestion 

Angiectasis 

Lymph node, mandibular 

Lymphatic, angiectasis 

Hyperplasia, lymphoid 

Depletion lymphoid 

Congestion 

Angiectasis 

Lymph node, mesenteric 

Lymph node 

99 

(49) 

1 (2%) 

22 (45%) 

(11) 

4 (36%) 

2 (18%) 

(49) 

4 (8%) 

2 (4%) 

1 (2%) 

1 (2%) 

5 (10%) 

1 (2%) 

(49) 

18 (36%) 

(18) 

1 (6%) 

1 (6%) 

1 (6%) 

1 (6%) 

4 (22%) 

2 (11%) 

(49) 

1 (2%) 

2 (4%) 

1 (2%) 

2 (4%) 

1 (2%) 

5 (10%) 

(50) 

(50) 

2 (4%) 

1 (2%) 

23 (46%) 

(15) 

1 (7%) 

3 (20%) 

4 (27%) 

1 (7%) 

1 (7%) 

(48) 

4 (8%) 

1 (2%) 

2 (4%) 

(48) 

2 (4%) 

3 (6%) 

1 (2%) 

1 (2%) 

2 (4%) 

20 (39%) 

(11) 

2 (18%) 

2 (18%) 

(51) 

3 (6%) 

3 (6%) 

1 (2%) 

1 (2%) 

(50) 

3 (6%) 

1 (2%) 

1 (2%) 

3 (6%) 
Lesions in Male Rats 

of Methylphenidate Hydrochloride (continued) 

Summary of the Incidence of Nonneoplastic Lesions in Male Rats in the 2-Year Feed Study 

TABLE A5 

Spleen 

Hematopoietic System (continued) 

2-Yew Study (continuat) 

(50) (50) (50) (51) 

Hemorrhage 

Hematopoietic cell proliferation 

Fibrosis 

Depletion lymphoid 

Congestion 

Capsule, fibrosis 

Capsule, congestion, focal 

Thrombosis 

Pigmentation, hemosiderin 

Necrosis, focal 

Inflammation, acute 

Infarct 

Congestion 

Lymphatic, angiectasis 

Hemorrhage, focal 

Depletion lymphoid 

1 (2%) 

1 (2%) 

3 (6%) 

3 (6%) 

1 (2%) 

2 (4%) 

2 (4%) 

1 (2%) 

1 (2%) 

2 (4%) 

2 (4%) 

2 (4%) 1 (2%) 

11 (22%) 

5 (10%) 

1 (2%) 

1 (2%) 

3 (6%) 

1 (2%) 

1 (2%) 

1 (2%) 

9 (18%) 

6 (12%) 

14 (28%) 17 (34%) 

1 (2%) 

Hypertrophy 

7 (14%) 

1 (2%) 1 (2%) 

1 (2%) 

Thymus (41) (47) (47) (49) 

1 (2%) 

1 (2%) 

1 (2%) 

Cyst 

2 (4%) 

2 (4%) 

1 (2%) 

1 (2%) 

Integumentary System 

Lactation 

Mammary gland 

Subcutaneous tissue, hemorrhage 

Hair follicle, cyst 

Ulcer 

Inflammation, focal, granulomatous 

Fibrosis, focal 

Edema 

Cyst epithelial inclusion 

Acanthosis 

Abscess 

Skin 

1 (2%) 

2 (4%) 

1 (2%) 

1 (2%) 

(50) 

(37) 

12 (32%) 

1 (2%) 

1 (2%) 

1 (2%) 

1 (2%) 

1 (2%) 

1 (2%) 

Bone 

Musculoskeletal System 

Proliferation 

Hyperostosis 

Cab3 

Fibrosis 

Skeletal muscle 

(49) 

1 (2%) 

5 (10%) 2 (4%) 3 (6%) 

1 (2%) 

(1) (6) 

2 (33%) 
110 Methylphenidate Hydrochloride, NTP TR 439 

of Methylphenidate Hydrochloride (continued) 

Summary of the Incidence of Nonneoplastic Lesions in Male Rats in the 2-Year Feed Study 

TABLE A5 

0 PPm 100 PPm 500 PPm PPm 

Brain 

Nervous System 

%Year Study (continued) 

Meninges, hemorrhage 

Hemorrhage 

Compression 

Degeneration 

Peripheral nerve 

Hemorrhage, focal 

Degeneration 

Spinal cord (1) 

(1) 

1 (100%) 

1 (100%) 

Lung 

Respiratory System 

Pleura, inflammation, chronic, focal 

Peribronchial, inflammation, chronic 

Infiltration cellular, focal, histiocyte 

Hemorrhage, focal 

Granuloma 

Congestion 

Angiectasis 

Respiratory epithelium, necrosis 

Metaplasia, squamous 

Inflammation, chronic 

Inflammation, acute 

Hyperplasia, basal cell 

Hyperkeratosis 

Fungus 

Nose 

(50) 

3 (6%) 

1 (2%) 

5 (10%) 

1 (2%) 

(50) 

16 (32%) 

2 (4%) 

2 (4%) 

2 (4%) 

1 (2%) 

1 (2%) 

(49) 

14 (29%) 

1 (2%) 

1 (2%) 

1 (2%) 

5 (10%) 

2 (4%) 

1 (2%) 

1 (2%) 

(49) (51) 

16 (33%) 14 (27%) 

1 (2%) 

1 (2%) 

3 (6%) 

1 (2%) 

6 (12%) 

7 (14%) 

Eye 

Special Senses System 

Retina, degeneration 

Cataract 

(1) (3) (3) (3) 

1 (33%) 

1 (33%) 3 (100%) 3 (100%) 

1 (100%) 2 (67%) 

Kidney 

Urinary System 

Autolysis 

Abscess 

Medulla, casts 

Nephropathy 

Necrosis, focal 

Mineralization 

Glomerulosclercpis 

Cyst 

Renal tubule, pigmentation, bile 

Renal tubule, degeneration, granular 

Pelvis, epithelium, hyperplasia 

Papilla, necrosis 

46 (94%) 

1 (2%) 

1 (2%) 

2 (4%) 

1 (2%) 

3 (6%) 

46 (92%) 47 (98%) 
Lesions in Male Rats 111 

of Methylphenidate Hydrochloride (continued) 

Summary of the Incidence of Nonneoplastic Lesions in Male Rats in the 2-Year Feed Study 

TABLE A5 

Ureter 

Urinary System (continued) 

2-Year Study (continued) 

Hyperplasia 

Transitional epithelium, hyperplasia 

Ulcer 

Hemorrhage 

Ektasia 

Calculus microscopic observation only 

Urinaty bladder (43) 

(1) 

1 (2%) 

1 (100%) 

1 (2%) 

1 (2%) 

(44) (43) 

1 (2%) 

1 (2%) 

1 (2%) 

1 (2%) 
112 Methylphenidate Hydrochloride, NTP TR 439 
113 

APPENDIX B 

SUMMARY OF LESIONS IN FEMALE RATS ?' 

.... 

IN THE 2-YEAR FEED STUDY .. 

OF METHYLPHENIDATE HYDROCHLORIDE 

TABLE B1 Summary of the Incidence of Neoplasms in Female Rats 

TABLE B2 Individual Animal Tumor Pathology of Female Rats 

TABLE B3 Statistical Analysis of Primary Neoplasms in Female Rats 

TABLE B4. Historical Incidence of Mammary Gland Fibroadenomas 

TABLE B5 Summary of the Incidence of Nonneoplastic Lesions in Female Rats 

in the 2-Year Feed Study of Methylphenidate Hydrochloride 

in Untreated Female F344/N Rats 

in the 2-Year Feed Study of Methylphenidate Hydrochloride 

in the 2-Year Feed Study of Methylphenidate Hydrochloride 

in the 2-Year Feed Study of Methylphenidate Hydrochloride .................... 

141 

140 

136 

120 

115 

.................... 

.................... 

........................................ 

.................... 
114 Methyiphenidate Hydrochloride, NTP TR 439 
Lesions in Female Rats 115 

Summary of the Incidence of Neoplasms in Female Rats in the 2-Year Feed Study of Methylphenidate Hydrochloridea 

TABLE B1 

Early deaths 

1IMd intaim ewIua&m 

PMd intaim ewIua&mb 

Animals initially in study 

Disposition Summary 

Terminal sacrifice 

Died last week of study 

Natural deaths 

Moribund 

SuMvors 

Animals examined microscopically 

10 

10 

70 

6 

13 

29 

2 

70 

10 

10 

70 

6 

12 

30 

2 

70 

10 

10 

70 

4 

10 

36 

70 

10 

10 

70 

4 

7 

38 

1 

70 

15-Month Interim Evaluation 

Stomach, forestomach 

Alimentary System 

(10) (10) (10) (10) 

Squamous cell papilloma 1 (10%) 

None 

Cardiovascular System 

Thyroid gland 

Pituitary gland 

Endocrine System 

C-cell, adenoma 

Pars distalis, adenoma 

None 

General Body System 

Genital System 

Polyp stromal, two 

Polyp stromal 

Uterus 

None 

Hematopoietic System 

Keratoacanthoma 

Skin 

Integumentary System 
116 Methylphenidate Hydrochloride, NTP TR 439 

(continued) 

Summary of the Incidence of Neoplasms in Female Rats in the 2-Year Feed Study of Methylphenidate Hydrochloride 

TABLE B1 

0 PPm 100 ppm PPm 1,000 ppm 

None 

Musculoskeletal System 

15-Month Interim Evaluation (continued) 

None 

Nervous System 

Lung 

Respiratory System 

Alveolarbronchiolar adenoma 

None 

Special Senses System 

Urinary System 

Adenoma 

Renal tubule 

Kidney 

.,;., . . 

., 

.$.,.j'' ,. ., . . .. .. 

, .. .. Intestine smali duodenum 

Fibmma' . . '. ' '. : 

.Intestine la@, .*I& 

Intestine small, ileum 

Intestine small, jejunum 

Sarcoma stromal, metastatic, uterus 

Liver 

Hepatocellular adenoma 

Sarcoma 

Sarcoma stromal, metastatic, uterus 

Sarcoma stromal, metastatic, uterus 

Sarcoma stromal, metastatic, uterus 

Saliiaty glands 

Pancreas 

Mesentety 

Tongue 

Stomach, glandular 

Stomach, forestomach 

Squamous cell papilloma 

Heart 

Cardiovascular System 
Lesions in Female Rats 117 

(continued) 

Summary of the Incidence of Neoplasms in Female Rats in the 2-Year Feed Study of Methylphenidate Hydrochloride 

TABLE B1 

0 PPm 100 PPm 500 PPm 1,000 ppm 

Adrenal medulla 

Endocrine System 

2-Year Study (continued) 

Pheochromocytoma benign 

Pheochromocytoma malignant 

Adenoma 

Parathyroid gland 

Adenoma 

Islets, pancreatic 

Pars distalis, carcinoma 

Pars distalis, adenoma, multiple 

Pars distalis, adenoma 

Pituitary gland 

Follicular cell, adenoma 

C-cell, carcinoma 

C-cell, adenoma 

Thyroid gland (50) 

3 (6%) 

1 (2%) 

(49) 

1 (2%) 

3 (6%) 

(49) 

(46) 

(49) 

29 (59%) 

1 (2%) 

2 (4%) 

3 (6%) 

(50) 

8 (16%) 

1 (2%) 

2 (4%) 

(50) 

3 (6%) 

(49) 

(46) 

(50) 

2 (4%) 

22 (45%) 

3 (6%) 

(50) 

4 (8%) 

1 (2%) 

None 

General Body System 

Adenoma 

Clitoral gland 

Genital System 

Granulosa cell tumor benign 

Adenoma, tubular 

Sarcoma stromal 

Polyp stromal 

,Leiomyoma 

(50) 

(45) 

(50) 

(48) 

(50) 

(49) 

(50) 

(49) 

1 (2%) 1 (2%) 

1 (2%) 

1 (2%) 

wary 

1 (2%) 

Uterus (50) (50) (50) (50) 

1 (2%) 

1 (2%) 

2 (4%) 

5 (10%) 9 (18%) 7 (14%) 7 (14%) 

1 (2%) 1 (2%) 

Vagina (1) (1) (4) (1) 

Lymph node, mandibular 

Lymph node 

Bone maBlood 

Hematopoietic System 

Spleen 

Lymph node, mesenteric 

(50) 

(8) 

(50) 

(2) 

(48) 

(50) 

(50) 

(50) 

(11) 

(50) 

(1) 

(50) 

(50) 

(50) 

(49) 

(6) 

(50) 

(1) 

(47) 

(50) 

(50) 

(50) 

(6) 

(50) 

(48) 

(49) 

(49) 

Sarcoma stromal, metastatic, uterus 

Fibrosarcoma, metastatic, skin 1 (2%) 

1 (2%) 

Thymus 
118 Methylphenidate Hydrochloride, NTP TR 439 

(continued) 

Summary of the Incidence of Neoplasms in Female Rats in the 2-Year Feed Study of Methylphenidate Hydrochloride 

TABLE B1 

0 PPm 100 ppm 500 ppm 1,000 PPm 

2-Year Study (continued) 

Integumentary System 

Fibrosarcoma 

Fibroadenoma, multiple 

Fibroadenoma 

Adenoma 

Adenocarcinoma 

Mammary gland 

Pinna, neurofibroma 

Trichoepithelioma 

Sarcoma 

Fibrosarcoma 

Fibroma 

Basal cell adenoma 

Skin 

(49) 

1 (2%) 

1 (2%) 

5 (10%) 

10 (20%) 

1 (2%) 

(50) 

1 (2%) 

(50) (48) 

1 (2%) 

12 (24%) 

4 (8%) 

6(13%) ~ 

1 (2%) 

1 (2%) 

(50) (50) 

1 (2%) 

1 (2%) 

2 (4%) 

1 (2%) 

1 (2%) 

Bone 

Musculoskeletal System 

Osteosarcoma 

Brain 

Nervous System 

(50) 

Carcinoma, metastatic, pituitary gland 

Astrocytoma malignant 

Spinal cord 

Lung 

Respiratory System 

(50) (50) (50) 

Pheochromocytoma malignant, metastatic, 

Fibrosarcoma, metastatic, skin 

Carcinoma, metastatic, thyroid gland 

Alveolarbronchiolar adenoma 

Squamous cell carcinoma, metastatic, ear 

1 (2%) 

1 (2%) 

2 (4%) 

1 (2%) adrenal medulla 

1 (2%) 

Zymbal’s gland 

Ear 

Special Senses System 

(1) 

(1) 

Carcinoma 

Squamous cell carcinoma, metastatic, ear 1 (100%) 

(1) (1) 

1 (100%) 

Kidney 

Urinary System 

Papilloma 

Urinary bladder 

Renal tubule, adenoma 

Lipoma 

(48) 

1 (2%) 
Lesions in Female Rats 119 

(continued) 

Summary of the Incidence of Neoplasms in Female Rats in the 2-Year Feed Study of Methylphenidate Hydrochloride 

TABLE B1 

0 PPm 100 ppm 500 ppm 1,000 ppm 

Multiple organs' 

Systemic Lesions 

Leukemia mononuclear 

Total animals with primary neoplasmsd 

Neoplasm Summary 

15-Month interim evaluation 

2-Year study 

15-Month interim evaluation 

2-Year study 

15-Month interim evaluation 

2-Year study 

15-Month interim evaluation 

2-Year study 

2-Year study 

2-Year study 

2-Year study 

2-Year study 

Total primary neoplasms 

Total animals with benign neoplasms 

Total benign neoplasms 

Total metastatic neoplasms 

Total animals with metastatic neoplasms 

Total malignant neoplasms 

Total animals with malignant neoplasms 

46 

3 

74 

3 

56 

3 

40 

3 

7 

2 

18 

18 

47 

4 

44 

4 

101 

4 

76 

4 

3 

25 

22 

4 

45 

5 

37 

5 

71 

6 

50 

6 

21 

20 

43 

3 

72 

3 

54 

3 

35 

3 

17 

18 

primary neoplasms: all neoplasms except metastatic neoplasms 

' Number of animals with any tissue examined microscopically 

No neoplasms were observed at any site in any animal at the 9-month interim evaluation. 

a Number of animals examined microscopically at site and number of animals with neoplasm 
120 Methylphenidate Hydrochloride, NTP TR 439 

0 PPm 

Individual Animal Tumor Pathology of Female Rats in the 2-Year Feed Study of Methylphenidate Hydrochloride: 

TABLE B2 

245556666666666667777'7777 

Number of Days on Study 

00135389000285'70489677777 

6556'714456666778822444444 

3214981769492713353936712 

4041440552336411530922233 

3333.333333333333333233333 

Carcass ID Number 

Alimentary System 

Intestine small, duodenum 

Intestine large, cecum 

Intestine large, rectum 

Intestine large, colon 

Esophagus 

Liver 

Intestine small, ileum 

Intestine small, jejunum 

MesenteIy 

Sarcoma stromal, metastatic, uterus 

Sarcoma stromal, metastatic, uterus 

++++A+++++A+++++A+++-+++++++ 

++++A++++AA+++++A++++++++ 

++++A++++++++++++++++++++ 

++++A++++A++++++A++++++++ 

......................... 

......................... 

++++A++++AA+++++A++++++++ 

++++A+++++A+++++A++++++++ 

X 

+ 

X 

+ + 

Sarcoma stromal, metastatic, uterus 

Sarcoma stromal, metastatic, uterus 

X 

X 

Pancreas 

Stomach, glandular 

Stomach, forestomach 

Salivary glands 

......................... 

......................... 

.......................... 

......................... 

Cardiovascular System 

Heart ......................... 

Adrenal medulla 

Adrenal cortex 

Endocrine System 

Pituitary gland 

Parathyroid gland 

Islets, pancreatic 

Thyroid gland 

Pheochromocytoma benign 

C-cell, carcinoma 

C-cell, adenoma 

Pars distalis, adenoma 

......................... 

+M+++++++++++++++++++++++ 

......................... X ......................... 

......................... 

X x xx xx x xxx ......................... xx 

General Body System 

None 

Genital System 

Granulosa cell tumor benign 

Ovary 

Adenoma 

Clitoral gland 

Vagina 

Sarcoma stromal 

Polyp stromal 

Uterus 

++++++++++++++++M++M+++++ 

X 

.......................... X 

X X ......................... 

xx 

+ 

A Autolysis precludes examination 

+: Tissue examined microscopically 

I: Insufficient tissue 

M: Missing tissue 

Blank: Not examined 

X Lesion present 
- Lesions in Female Rats 121 

0 ppm (continued) 

Individual Animal Tumor Pathology of Female Rats in the 2-Year Feed Study of Methylphenidate Hydrochloride: 

TABLE B2 

7777777777777788888888888 

4444444444444444444444444 

7777777777777777777777777 

3333333333333323333333333 Total 

3344455555666690000011111 Tissues/ 

6124512459014581458926789 Tumors 

Number of Days on Study 

Carcass ID Number 

Intestine small, duodenum 

Intestine large, cecum 

Intestine large, rectum 

Intestine large, colon 

Esophagus 

Alimentary System 

Liver 

Intestine small, ileum 

Intestine small, jejunum 

Salivary glands 

Pancreas 

Mesentery 

Stomach, glandular 

Stomach, forestomach 

......................... 47 

......................... 46 

......................... 49 

......................... 47 

......................... 50 

......................... 50 

......................... 46 

......................... 47 

1 

1 

4 

1 

......................... 50 

......................... 50 

......................... 50 

1 

......................... 50 

Sarcoma stromal, metastatic, uterus 

Sarcoma stromal, metastatic, uterus 

Sarcoma stromal, metastatic, uterus 

Sarcoma stromal, metastatic, uterus 

+ 

Cardiovascular System 

Heart ......................... 50 

Adrenal medulla 

Adrenal cortex 

Endocrine System 

Pituitary gland 

Parathyroid gland 

Islets, pancreatic 

Thyroid gland 

1 

X 3 

......................... 50 

xx xxx 26 

......................... 50 

+++++++M+++++++++++++M+++ 47 

......................... 50 

3 

......................... 50 

......................... 50 

Pheochromocytoma benign X X 

General Body System 

C-cell, carcinoma 

C-cell, adenoma 

Pars distalis, adenoma xxxxxxxxx xx 

X 

None P 

Genital System 

Clitoral gland 

Polyp stromal 

Granulosa cell tumor benign 

Adenoma 

Sarcoma stromal 

1 

2 

xx X 5 

......................... 50 

1 

......................... 50 

1 

++++++M+++M++++M+++++++++ 45 

ovary 

Uterus 

Vagina 
122 Methylphenidate Hydrochloride, NTP TR 439 

0 ppm (continued) 

Individual Animal Tumor Pathology of Female Rats in the 2-Year Feed Study of Methylphenidate Hydrochloride: 

TABLE B2 

0013538900028570489677777 

6556714456666778822444444 

2455566666666666677777777 

Number of Days on Study 

3333333333333333333233333 

Carcass ID Number 

3214987769492713353936712 

4041440552336411530922233 

Hematopoietic System 

Blood ' + + 

Lymph node, mesenteric 

Lymph node, mandibular 

Lymph node 

Bone marrow 

......................... 

......................... 

......................... +++ + ++ ++ 

Sarcoma stromal, metastatic, uterus X 

Spleen 

Thymus +++++++++++++M+++++M+++++ 

......................... 

Integumentary System 

Fibrosarcoma 

Fibroadenoma, multiple 

Fibroadenoma 

Adenocarcinoma 

Mammary gland 

Trichoepithelioma 

Basal cell adenoma 

++++++++++++,++++++M++++++ 

x x x xx 

X 

Skin ......................... X 

X 

Musculoskeletal System 

Skeletal muscle 

Bone ......................... + 

Nervous System 

Brain ......................... 

Respiratory System 

Lung ......................... Squamous cell carcinoma, metastatic, 

Trachea 

Nose 

ear X 

......................... 

......................... 

Special Senses System 

Ear 

Squamous cell carcinoma, metastatic, 

ear 

Eye 

Zymbal's gland 

Harderian gland 

+ + 

+ 

X 

+ 

Urinary bladder 

Kidney 

Urinary System 

++++A+++++A+++++A++++++++ 

......................... 

Systemic Lesions 

Multiple organs 

Leukemia mononuclear 

......................... xxxxx xx xxxxx 
Lesions in Female Rats 123 

0 ppm (continued) 

Individual Animal Tumor Pathology of Female Rats in the 2-Year Feed Study of Methylphenidate Hydrochloride: 

TABLE B2 

11111111111111888888888~8 

4444444444444444444444444 

1111111111111111111111111 

Number of Days on Study 

Carcass ID Number 

3333333333333323333333333 

6124512459014581458926789 Tumors 

3344455555666690000011111 Tissues1 

Total 

Hematopoietic System 

Lymph node, mesenteric 

Lymph node, mandibular 

Lymph node 

Bone marrow 

Blood 

Thymus 

Spleen 

......................... 48 

......................... 50 

1 

......................... 50 

......................... 50 

8 

......................... 50 

2 

Sarcoma stromal, metastatic, uterus 

Integumentary System 

Fibrosarcoma 

Fibroadenoma, multiple 

Fibroadenoma 

Adenocarcinoma 

Mammary gland 

Trichoepithelioma 

Basal cell adenoma 

1 

1 

......................... 50 

1 

5 

xx 10 

1 

......................... 49 

X 

xx X 

X 

X X X X 

Skin 

Musculoskeletal System 

Skeletal muscle 

Bone 

1 

......................... 50 

Nervous System 

Brain ......................... 50 

~~~ ~ ~ ~ 

Respiratory System 

~~~~ _____ ___ ~ 

Lung ......................... 50 

......................... 50 

......................... 50 

1 

Squamous cell carcinoma, metastatic, 

Trachea 

Nose 

ear 

Special Senses System 

Ear 1 

1 

1 

2 

1 

Squamous cell carcinoma, metastatic, 

ear 

Eye 

Zymbal’s gland 

Harderian gland + 

Urinary bladder 

Kidney 

Urinary System 

......................... 50 

........................... 41 

Systemic Lesions 

Multiple organs 

13 

......................... 50 

Leukemia mononuclear X 
124 Methylphenidate Hydrochloride, NTP TR 439 

100 ppm 

Individual Animal Tumor Pathology of Female Rats in the 2-Year Feed Study, of Methylphenidate Hydrochloride: 

TABLE B2 

08499201.15923801891333333 

5897136788911122224444444 

4445666666677~711111177717 

8672208926404566411912357 

6283201911312306808611717 

343444334-3434443343333333 

Number of Days on Study 

Carcass ID Number 

Alimentary System 

Liver 

Intestine small, ileum 

Intestine small, jejunum 

Intestine small, duodenum 

Intestine large, cecum 

Intestine large, rectum 

Intestine large, colon 

Esophagus 

Stomach, glandular 

Stomach, forestomach 

Salivary glands 

Pancreas 

Mesentery 

Hepatocellular adenoma 

......................... 

+AA++++++++A+A+++AA++++++ 

+AA++++++++AAA+++AA++++++ 

+AA++.++++++A++++++A++++++ 

+AA++++++++A+++++AA++++++ 

+A+++++++++A++++++A++++++ 

+++++++++++A+++++AA++++++ 

......................... 

X 

+ ++ 

++++++++++++++++++A++++++ 

++++++++++++++++++A++++++ 

......................... 

++++++++++++++++++A++++++ 

+ 

Cardiovascular System 

Heart ......................... 

Adrenal medulla 

Adrenal cortex 

Endocrine System 

Adenoma 

Islets, pancreatic 

Pheochromocytoma benign 

Pheochromocytoma malignant 

Pituitary gland 

Adenoma 

Parathyroid gland 

Pars distalis, adenoma, multiple 

Pars distalis, adenoma 

Follicular cell, adenoma 

C-cell, carcinoma 

C-cell, adenoma 

Thyroid gland 

++++++++++++++++++A++++++ 

++++++++++++++++++A++++++ 

++++++++++++++++++A++++++ 

X 

X x x x xxx xxx xx X 

++++++++++++++++++A++++++ 

++++++++++++++++M++++++++ 

X 

X ......................... X X 

General Body System 

None 

Genital System 

Adenoma 

Clitoral gland 

Ovary 

Uterus 

Sarcoma stromal 

Polyp stromal 

Vagina 

............................ X 

X ......................... 

......................... 

X X X xx X 

-+ 
Lesions in Female Rats 125 

100 ppm (continued) 

Individual Animal Tumor Pathology of Female Rats in the 2-Year Feed Study of Methylphenidate Hydrochloride: 

TABLE B2 

3344444444444444417177711 

4444444444444444444444444 

1111111111111111111111117 

3433333334444444444444444 Total 

1018889990001112311222233 Tissues/ 

9242380383581563139018903 Tumors 

Number of Days on Study 

Carcass ID Number 

Liver 

Intestine small, ileum 

Intestine small, jejunum 

Intestine small, duodenum 

Intestine large, cecum 

Intestine large, rectum 

Intestine large, colon 

Esophagus 

Alimentary System 

Stomach, glandular 

Stomach, forestomach 

Salivary glands 

Pancreas 

Mesentery 

Hepatocellular adenoma 

......................... 50 

+A+++++++++++++++++++++++ 43 

.......................... 43 

......................... 46 

......................... 45 

......................... 47 

......................... 

......................... 50 

......................... 49 

......................... 49 

......................... 50 

......................... 49 

6 

1 

47 

+ + 

Cardiovascular System 

Heart ......................... 50 

Adrenal medulla 

Adrenal cortex 

Endocrine System 

......................... 49 

......................... 49 

X 1 

1 

2 

xx xx 8 

......................... 50 

3 

xxx xx xxxxxxxxx 29 

......................... 49 

1 

++++++MM+++++M+++++++++++ 46 

2 

......................... 49 

3 

Islets, pancreatic 

Pheochromocytoma benign 

Pheochromocytoma malignant 

Adenoma 

Parathyroid gland 

Adenoma 

Pars distalis, adenoma, multiple 

Pars distalis, adenoma 

Pituitary gland 

Follicular cell, adenoma 

C-cell, carcinoma 

C-cell, adenoma 

X X X 

X 

xx 

X X 

Thyroid gland 

X X 

X X 

X 

General Body System 

None 

Genital System 

Clitoral gland 

Uterus 

ovary 

Adenoma 

Sarcoma stromal 

Polyp stromal 

Vagina 

++++++++++M+++++++++M++++ 48 

1 

1 

9 

......................... 50 

......................... 50 

1 

xx 

X 
126 Methylphenidate Hydrochloride, NTP TR 439 

100 ppm (continued) 

Individual Animal Tumor Pathology of Female Rats in the 2-Year Feed Study of Methylphenidate Hydrochloride: 

TABLE B2 

Number of Days on Study 

084'99201159238'01891333333 

5891136188911122224444444 

4445666666611111111111111 

8612208926404566411912351 

6283201911372306808611111 

3434443343434443343333333 

Carcass ID Number 

Hematopoietic System 

Lymph node, mandibular 

Lymph node 

Bone marrow ......................... + + + ......................... Fibrosarcoma, metastatic, skin X 

Thymus 

Spleen 

Lymph node, mesenteric 

......................... 

......................... 

......................... 

Integumentary System 

Fibroadenoma, multiple 

Fibroadenoma 

Adenocarcinoma 

Mammary gland 

Sarcoma 

Fibrosarcoma 

Fibroma 

Basal cell adenoma 

Skin 

X 

......................... X X 

xx X X 

......................... 

X 

X 

Musculoskeletal System 

Skeletal muscle 

Bone ......................... 

Nervous System 

Brain .......................... Astrocytoma malignant 

Respiratory System 

Lung .......................... 

metastatic, adrenal medulla 

Pheochromocytoma malignant, 

Fibrosarcoma, metastatic, skin 

Carcinoma, metastatic, thyroid gland 

Alveolar/bronchiolar adenoma X 

X 

Trachea 

Nose 

......................... 

......................... 

Zymbal's gland 

Special Senses System 

Eye + 

+ 

Urinary bladder 

Kidney 

Urinary System 

+AA++++++++AA++++AA++++++ 

++A++++++++++++++++++++++ 

Systemic Lesions 

Multiple organs ......................... Leukemia mononuclear x xx, x x xx X 
Lesions in Female Rats 127 

100 ppm (continued) 

Individual Animal Tumor Pathology of Female Rats in the 2-Year Feed Study of Methylphenidate Hydrochloride: 

TABLE B2 

3344444444444444477777777 

4444444444444444444444444 

7777777777777777777777777 

Number of Days on Study 

Carcass ID Number 

9242380383581563139018903 

7078889990001112311222233 

3433333334444444444444444 

Tumors 

Tissues/ 

Total 

Hematopoietic System 

Lymph node, mandibular 

Lymph node 

Bone marrow 

Thymus 

Spleen 

Lymph node, mesenteric 

Fibrosarcoma, metastatic, skin 

......................... ++ + ......................... 

++++M+++++++++++M++++++++ 

......................... 

......................... 

48 

49 

49 

1 

50 

6 

50 

Integumentary System 

Fibroadenoma, multiple 

Fibroadenoma 

Adenocarcinoma 

Mammary gland 

Sarcoma 

Fibrosarcoma 

Fibroma 

Basal cell adenoma 

~~ ~ 

Skin 

xx X X 

......................... X 

X 

xx xx 

......................... X 

X X 

1 

1 

2 

1 

50 

1 

12 

4 

50 

Musculoskeletal System 

Skeletal muscle 

Bone 

1 

......................... 50 

+ 

Nervous System 

Brain 

Astrocytoma malignant 1 

......................... 50 

X 

Respiratory System 

Lung 

1 

1 

2 

......................... 50 

X 1 

......................... 50 

......................... 50 

Pheochromocytoma malignant, 

Fibrosarcoma, metastatic, skin 

Carcinoma, metastatic, thyroid gland 

Alveolarbronchiolar adenoma 

metastatic, adrenal medulla 

X 

X 

Trachea 

Nose 

Zymbal’s gland 

Special Senses System 

Eye 1 

1 

Urinary bladder 

Kidney 

Urinary System 

......................... 49 

......................... 44 

Systemic Lesions 

Multiple organs ......................... 50 

Leukemia mononuclear x xx X xx 14 
128 Methylphenidate Hydrochloride, NTP TR 439 

500 ppm 

Individual Animal Tumor Pathology of Female Rats in the 2-Year Feed Study of Methylphenidate Hydrochloride: 

TABLE B2 

8569678865580022222222222 

8263468347783344444444444 

2445555666667777777777777 

5679834057952204589346789 

6369748803656844444555555 

4444444454444444444444444 

Number of Days on Study 

Carcass ID Number 

Intestine large, colon 

Esophagus 

Alimentary System 

++++++A++++++++++++++++++ 

......................... 

Tongue 

Stomach, glandular 

Stomach, forestomach 

Salivary glands 

Pancreas 

Mesentery 

Liver 

Intestine small, ileum 

Intestine small, jejunum 

Intestine small, duodenum 

Intestine large, cecum 

Intestine large, rectum 

Squamous cell papilloma 

......................... 

A+A+++A++++++++++++++++++ 

A+++++A++++++++++++++++++ 

......................... 

++++++A++++++++++++++++++ 

......................... 

+ + + + 

......................... 

......................... 

......................... 

......................... + 

Cardiovascular System 

Heart ......................... 

Adrenal medulla 

Adrenal cortex 

Endocrine System 

Islets, pancreatic 

Pheochromocytoma benign 

Pheochromocytoma malignant 

Pituitary gland 

Parathyroid gland 

Adenoma 

Pars distalis, carcinoma 

Pars distalis, adenoma, multiple 

Pars distalis, adenoma 

C-cell, adenoma 

Thyroid gland 

......................... 

......................... 

X X ......................... 

......................... 

++M++++++++++++++++++++++ 

X X X X X 

......................... X xx 

General Body System 

None 

Genital System 

Adenoma, tubular 

Ovary 

Adenoma 

Clitoral gland 

Vagina 

Sarcoma stromal 

Polyp stromal 

Uterus 

+++++++M+++++++++++++++++ 

X ......................... X ......................... X ,X X X 

+ + + 
Lesions in Female Rats 129 

TABLE B2 

500 ppm (continued) 

Individual Animal Tumor Pathology of Female Rats in the 2-Year Feed Study of Methylphenidate Hydrochloride: 

2222222222233333333333333 

4444444444444444444444444 

77777111117111111711111~7 

4444444444444444444445555 Total 

6666717188811889999990000 Tissues/ 

0148123468969131256780123 Tumors 

Number of Days on Study 

Carcass ID Number 

Alimentary System 

Tongue 

Stomach, glandular 

Stomach, forestomach 

Salivary glands 

Pancreas 

Mesentery 

Liver 

Intestine small, ileum 

Intestine small, jejunum 

Intestine small, duodenum 

Intestine large, cecum 

Intestine large, rectum 

Intestine large, colon 

Esophagus 

Squamous cell papilloma 

......................... 50 

......................... 49 

......................... 50 

......................... 49 

......................... 50 

......................... 48 

......................... 41 

......................... 50 

+ 9 

.......................... 50 

......................... 50 

......................... 50 

......................... 50 

1 

1 

+ ++ 

X 

+ 

Cardiovascular System 

Heart ......................... 50 

Adrenal medulla 

Adrenal cortex 

Endocrine System 

Pituitary gland 

Parathyroid gland 

Adenoma 

Islets, pancreatic 

Pheochromocytoma benign 

Pheochromocytoma malignant 

Pars distalis, carcinoma 

Pars distalis, adenoma, multiple 

Pars distalis, adenoma 

C-cell, adenoma 

Thyroid gland 

.......................... 

X 7 

......................... 50 

X 1 

5 

X 15 

......................... 50 

l++++++++++++++++M++++++++ 48 

X 1 

......................... 50 

3 

2 

......................... 50 

50 

X X 

X 

xx x xx xxx X 

X X X xx 

xx X 

General Body System 

None 

Genital System 

Clitoral gland 

Polyp stromal 

Adenoma, tubular 

Adenoma 

Sarcoma stromal 

ovary 

Uterus 

Vagina 

50, 

1 

......................... 49 

4 

1 

7 

......................... 50 

1 

......................... 

X X 

+ 

X 

X 
130 Methylphenidate Hydrochloride, NTP TR 439 

TABLE B2 

500 ppm (continued) 

Individual Animal Tumor Pathology of Female Rats in the 2-Year Feed Study of Methylphenidate Hydmf”de: 

8569678865580022222222222 

8263468347783344444444444 

2445555666667777777777777 

5679834057952204589346789 

6369748803656844444555555 

4444444454444444444444444 

Number of Days on Study 

Carcass ID Number 

Hematopoietic System 

Bone marrow 

Blood + ......................... 

Thymus 

Spleen 

Lymph node, mesenteric 

Lymph node, mandibular 

Lymph node + + ++ + 

......................... 

......................... 

......................... 

......................... 

Integumentary System 

Skin 

’ Adenoma 

Mammary gland 

Sarcoma 

Fibroadenoma 

Adenocarcinoma 

++++M++++++++++++++++++++ 

X 

X X 

......................... X 

Musculoskeletal System 

Skeletal muscle 

Bone ......................... + 

Nervous System 

Brain M++++++++++++++++++++++++ 

Respiratory System 

Spinal cord 

, gland 

Carcinoma, metastatic, pituitary 

Trachea 

Nose 

Lung 

......................... 

......................... 

......................... 

Carcinoma 

Zymbal’s gland 

Special Senses System 

X 

+ 

~~~ 

Urinary bladder 

Kidney 

Urinary System 

~~ ~~ 

A++++++++++A+++++++++++++ 

Papilloma 

Lipoma X 

A+++++A++++A+++++++++++++ 

Systemic Lesions 

Multiple organs 

Leukemia mononuclear X ......................... x xx x xx xx 
Lesions in Female Rats 131 

500 ppm (continued) 

Individual Animal Tumor Pathology of Female Rats in the 2-Year Feed Study of Methylphenidate Hydrochloride: 

TABLE B2 

Number of Days on Study 

2222222222233333333333333 

4444444444444444.444444444 

7777777177777717777777717 

Carcass ID Number 

4444444444444444444445555 Total 

6666777788877889999990000 TissUesl 

0148123468969131256180123 Tumors 

Hematopoietic System 

Lymph node, mesenteric 

Lymph node, mandibular 

Lymph node 

Bone marrow 

Blood 

......................... 50 

......................... 50 

11 

......................... 50 

1 

+ + ++ + + 

Spleen ......................... 50 

Thymus ......................... 50 

Mammary gland 

Integumentary System 

1 

1 

+M+++++++++++++++++++++++ 48 

1 

......................... 50 

Fibroadenoma X X X 6 

Adenoma 

Adenocarcinoma 

Sarcoma 

X 

X 

Skin 

Musculoskeletal System 

Skeletal muscle 

Bone 

1 

......................... 50 

Nervous System 

Brain 

1 

X 1 

......................... 49 

Carcinoma, metastatic, pituitary 

Spinal cord 

gland 

+ 

Respiratory System 

Trachea 

NoSe 

Lung ......................... 50 

......................... 50 

......................... 50 

Carcinoma 

Zymbal’s gland 

Special Senses System 

1 

1 

Urinary bladder 

Kidney 

Urinary System 

Papilloma 

Lipoma 

1 

......................... 47 

1 

......................... 48 

X 

Systemic Lesions 

Multiple organs 

Leukemia mononuclear 14 

......................... 50 

xxxx X 
132 Methylphenidate Hydrochloride, NTP TR 439 

1,000 ppm 

Individual Animal Tumor Pathology of Female Rats in the 2-Year Feed Study of Methylphenidate Hydrochloride: 

TABLE B2 

4209197896477777811111111 

0435913567133333344444444 

445556666677777777777777'7 

Number of Days on Study 

Carcass ID Number 

9233086329523459203456789 

0165456476622222511111111 

5555555555555555555555555 

Intestine large, colon 

Esophagus 

Alimentary System 

Intestine small, ileum 

Intestine small, jejunum 

Intestine small, duodenum 

Intestine large, cecum 

Intestine large, rectum 

Fibroma 

fongue 

Stomach, glandular 

Stomach, forestomach 

Salivary glands 

Pancreas 

Mesentery 

Liver 

Sarcoma 

~~ 

+++++A+++++++++++++++++++ 

......................... 

+++++A++++A++++++++++++++ 

......................... 

......................... 

......................... 

......................... 

......................... + ......................... X 

+ 

......................... 

......................... 

......................... 

X 

+ 

Squamous cell papilloma 

Cardiovascular System 

Heart ......................... 

Adrenal medulla 

Adrenal cortex 

Endocrine System 

Islets, pancreatic 

Pheochromocytoma benign 

Pituitary gland 

Parathyroid gland 

Adenoma 

C-cell, carcinoma 

C-cell, adenoma 

Pars distalis, adenoma, multiple 

Pars distalis, adenoma 

Thyroid gland 

......................... 

+++++++++++++++ +++++++++ 

xxx ......................... 

X xx ......................... 

+M+++++++++M+M++++M++++++ 

......................... X 

xx xxx X 

X 

X 

General Body System 

None 

Genital System 

Clitoral gland +++++M+++++++++++++++++++ 

Ovary ......................... 

......................... Uterus 

Sarcoma stromal 

Polyp stromal 

Leiomyoma 

Vagina 

X X 

X 

X 
Lesions in Female Rats 133 

1,000 ppm (continued) 

Individual Animal Tumor Pathology of Female Rats in the 2-Year Feed Study of Methylphenidate Hydrochloride: 

TABLE B2 

1111111111111111122222222 

4444444444444444444444444 

1111717111111111111111111 

8012345861478034562565902 Tumors 

2333333456666117'734445566 Tissues/ 

. .5555555555555555555555555 Total 

Number of Days on Study 

Carcass ID Number 

Esophagus 

Alimentary System 

+++++++++M+++++++++++++++ 49 

Intestine large, colon 

Intestine small, ileum 

Intestine small, jejunum 

Intestine small, duodenum 

Intestine large, cecum 

Intestine large, rectum 

Stomach, forestomach 

Salivary glands 

Pancreas 

Mesentery 

Liver 

Sarcoma 

Fibroma 

......................... 50 

......................... 50 

50 

3 

.......................... 50 

1 

.......................... 48 

......................... 48 

......................... 49 

......................... 48 

......................... 50 

1 

......................... 49 

X 

+ ......................... 

Tongue 

Stomach, glandular 

1 

1 

......................... 50 

Squamous cell papilloma 

Cardiovascular System 

Heart ......................... 50 

Adrenal medulla 

Adrenal cortex 

Endocrine System 

......................... 49 

......................... 50 

Islets, pancreatic 

Pheochromocytoma benign 

Pituitary gland 

Parathyroid gland 

Adenoma 

C-cell, carcinoma 

C-cell, adenoma 

Pars distalis, adenoma, multiple 

Pars distalis, adenoma 

Thyroid gland 

......................... X X 

++++++++++M+++,+++++++++++ 

......................... 

xx x x xxx x x xx 

X X 

......................... X xx 

1 

4 

50 

3 

22 

49 

46 

2 

50 

3 

General Body System 

None 

Uterus 

Ovary 

Clitoral gland 

Genital System 

......................... 49 

......................... 50 

.......................... 50 

1 

1 

X I 

1 

Sarcoma stromal 

Polyp stromal 

Leiomyoma 

X X X 

X 

Vagina + 
134 Methylphenidate Hydrochloride, NTP TR 439 

1,000 ppm (continued) 

Individual Animal Tumor Pathology of Female Rats in the 2-Year Feed Study of Methylphenidate Hydrochloride: 

TABLE B2 

4209197896477777811111111 

0435913567133333344444444 

4455566666777777777777777 

9233086329523459203456789 

0165456476622222511111111 

5555555555555555555555555 

Number of Days on Study 

Carcass ID Number 

Hematopoietic System 

Lymph node 

Bone marrow 

Blood 

Spleen 

Lymph node, mesenteric 

. Lymph node, mandibular 

+ ......................... 

+++++M++++++++++M++++++++ 

......................... 

......................... 

++++++++++++++++M++++++++ 

+ ++ + 

Thymus 

Integumentary System 

Fibroadenoma, multiple 

Fibroadenoma 

Adenocarcinoma 

Mammary gland 

Pinna, neurofibroma 

Basal cell adenoma 

......................... 

X 

X 

X X 

......................... X 

Skin 

X 

Osteosarcoma 

Musculoskeletal System 

Bone ......................... X 

Nei-vous System 

Spinal cord 

Peripheral nerve 

Brain ......................... 

+ 

+ 

Respiratory System 

Trachea 

Nose 

Lung 

......................... 

.......................... 

......................... 

Harderian gland 

Special Senses System 

Eye + 

Kidney 

Urinary System 

+++++A+++++++++++++++++++ 

Papilloma 

Renal tubule, adenoma 

Urinary bladder 

X 

A++++A+++++++++++++++++++ 

Systemic Lesions 

Multiple organs ......................... Leukemia mononuclear xxxxx X X 
Lesions in Female Rats 135 

1,000 ppm (continued) 

Individual Animal Tumor Pathology of Female Rats in the 2-Year Feed Study of Methylphenidate Hydrochloride: 

TABLE B2 

Number of Days on Study 

1111111111111111122222222 

4444444444444444444444444 

1111111171117111111111117 

5555555555555555555555555 Total 

2333333456666111734445566 Tissues/ 

8012345861418034562565902 Tumors 

Carcass ID Number 

Hematopoietic System 

Thymus 

Spleen 

Lymph node, mesenteric 

Lymph node, mandibular 

Lymph node 

Bone marrow 

Blood 

++++++M++++++++++++++++++ 47 

......................... 50 

......................... 50 

......................... 49 

6 

......................... 50 

1 

+ + 

Integumentary System 

Fibroadenoma, multiple 

Fibroadenoma 

Adenocarcinoma 

Mammary gland 

Pinna, neurofibroma 

Basal cell adenoma 

Skin 

2 

3 

1 

......................... 50 

1 

1 

......................... 50 

X 

X 

Osteosarcoma 

Musculoskeletal System 

Bone 

1 

......................... 50 

Nervous System 

Spinal cord 

Peripheral nelve 

Brain 

1 

1 

......................... 50 

Respiratory System 

Trachea 

Nose 

Lung ......................... 50 

......................... 50 

......................... 50 

Harderian gland 

Special Senses System 

Eye + 

+ 

t 2 

2 

Urinary bladder 

Kidney 

Urinary System 

Papilloma 

Renal tubule, adenoma 

1 

......................... 48 

2 

......................... 49 

X 

X ~ 

Systemic Lesions ~~ 

Multiple organs 

Leukemia mononuclear 13 

......................... 50 

x xx X X X 
136 Methylphenidate Hydrochloride, NTP Tk 439 

Statistical Analysis of Primary Neoplasms in Female Rats in the 2-Year Feed Study of Methylphenidate Hydrochloride 

TABLE B3 

Fisher exact test 

Cochran-Armita e testd 

Logistic regression testsd 

Life table tests 

First incidence days 

Terminal rates' 

Adjusted ratesb 

Overall ratesa 

Adrenal Medulla: Benign Pheochromocytoma 

Fisher exact test 

Cochran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

Adrenal'Medulla: Benign or Malignant Pheochromocytoma 

Fisher exact test 

Cochran-Annitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

Mammary Gland: Fibroadenoma 

Fisher exact test 

Cochran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

Mammary Gland: Fibroadenoma or Adenoma 

Fisher exact test 

Cochran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

Mammary Gland: Carcinoma 

3131 (10%) 

9.7% 

3/50 (6%) 

P=0.570N 

P=0.550N 

P=0.449N 

3 

d) ~ 737 (T) 

3/31 (10%) 

9.7% 

3/50 (6%) 

P=0.535N 

P=0.506N 

P=O.396N 

737 (T) 

P=0.003N 

P=0.002N 

Pc0.001N 

680 

13/31 (42%) 

45.3% 

15/50 (30%) 

P=0.004N 

P=0.002N 

P<0.001N 

680 

13/31 (42%) 

45.3% 

15/50 (30%) 

3.2% 

1/50 (2%) 

737 (T) 

1/31 (3%) 

P=0.263N 

P=0.257N 

P=0.212N 

3/31 (10%) 

9.7% 

3/49 (6%) 

P=O.651 

P=O.665 

P =0.665 

737 0 

P=O.500 

P-0.500 

737 0 

4/31 (13%) 

12.9% 

4/49 (8%) 

P=O.489 

38.0% 

13/50 (26%) 

P=0.280N 

P=0.361N 

720 

P=O.412N 

11/32 (34%) 

38.0% 

13/50 (26%) 

P=0.280N 

P=0.361N, 

720 

11/32 (34%) 

P=0.412N 

P=O.202 

P=O.203 

699 

2/32 (6%) 

11.3% 

4/50 (8%) 

P=O.181 

7.6% 

3/50 (6%) 

P-0.661N 

P=0.607N 

546 

P=0.661N 

2/36 (6%) 

13.0% 

5/50 (10%) 

P=O.363 

P=O.427 

546 

P=O357 

4/36 (11%) 

P=O.O14N 

P=O.OlON 

638 

5/36 (14%) 

15.9% 

6/50 (12%) 

P=0.024N 

P=0.026N 

P=0.019N 

638 

6/36 (17%) 

18.6% 

7/50 (14%) 

P=0.045N 

1/50 (2%) 

P=0.753N 

P=0.728N 

P=0.728N 

1/36 (3%) 

2.8% 

737 (T) 

3/39 (8%) 

7.7% 

3/50 (6%) 

P=0.661N 

P=0.553N 

P=0.553N 

737 0 

P-0.553N 

P=O.553N 

737 0 

3/39 (8%) 

7.7% 

3/50 (6%) 

P=0.661N 

P=O.ooSN 

P=O.W3N 

559 

3/39 (8%) 

11.7% 

5/50 (10%) 

P=O.OllN 

P=O.O08N 

P=O.O03N 

559 

3/39 (8%) 

11.7% 

5/50 (10%) 

P=O.OllN 

P=O.755 

P=0,733N 

619 

OB9 (0%) 

2.2% 

1/50 (2%) 

P=0.753N 
Lesions in Female Rats 137 

(continued) 

Statistical Analysis of Primary Neoplasms in Female Rats in the 2-Year Feed Study of Methylphenidate Hydrochloride 

TABLE B3 

Fisher exact test 

Cochran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

Mammary Gland: Adenoma or Carcinoma 

Fisher exact test 

Gxhran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

Mammary Gland Fibroadenoma, Adenoma, or Carcinoma 

Fisher exact test 

Cochran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

Pituitary Gland (Pars Distalis): Adenoma 

Fisher exact test 

Cochran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

Pituitary Gland (Pars Distalis): Adenoma or Carcinoma 

Fisher exact test 

Cochran-hitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

Thyroid Gland (C-cell): Adenoma 

737 (T) 

1/31 (3%) 

1/50 (2%) 

3.2% 

P=0.307N 

P=0.299N 

P=0.244N 

P<0.001N 

P<0.001N 

P<O.OOlN 

680 

14/31 (45%) 

48.3% 

16/50 (32%) 

P=0.174N 

P=0.153N 

P=0.035N 

551 

17/31 (55%) 

64.4% 

26/50 (52%) 

P=0.183N 

P=O.l62N 

P=0.036N 

551 

17/31 (55%) 

64.4% 

26/50 (52%) 

7.7% 

3/50 (6%) 

P=0.443N 

P=0.414N 

P=0.304N 

649 

1/31 (3%) 

P=O.u)2 

P=O.u)3 

699 

2/32 (6%) 

11.3% 

4/50 (8%) 

P=O.181 

P=0.527N 

P=O.561 

699 

13/32 (41%) 

46.9% 

17/50 (34%) 

P=O.500 

P=O.152 

P=O.238 

450 

21/31 (68%) 

75.5% 

32/49 (65%) 

P=O.127 

75.5% 

32/49 (65%) 

P=O.152 

P=O.238 

450 

21/31 (68%) 

P=O.127 

P=O.107 

P=O.124 

660 

6/32 (19%) 

22.5% 

8/50 (16%) 

P=O.loo 

(6%) 

2/50 (4%) 

5.6% 

737 0 

P=O.500 

P=O.552 

P=O.552 

P=O.OUN 

P=0.019N 

638 

7/36 (19%) 

21.3% 

8/50 (16%) 

P=O.O5ON 

P=0.138N 

P=0.074N 

567 

17B6 (47%) 

50.9% 

2W50 (40%) 

P=0.158N 

P=0.188N 

P=O.lOlN 

567 

18/36 (50%) 

53.5% 

21/50 (42%) 

P=O.212N 

P=O.167 

P=O.215 

730 

6/36 (17%) 

18.9% 

7/50 (14%) 

P=O.159 

P=O.755 

P=0.733N 

619 

0139 (0%) 

2.2% 

1/50 (2%) 

P=0.753N 

P-0.004N 

P-0.002N 

559 

3/39 (8%) 

11.7% 

5/50 (10%) 

P=0.006N 

P=0.493N 

P=0.216N 

404 

21/38 (55%) 

59.1% 

25/49 (51%) 

P=0.541N 

P=0.493N 

P=0.216N 

404 

21/38 (55%) 

59.1% 

25/49 (51%) 

P=0.541N 

10.3% 

4/50 (8%) 

737 (T) 

4/39 (10%) 

P=O.500 

P=O.515 

P=O.589 
138 Methylphenidate Hydrochloride, NTP TR 439 

(continued) 

Statistical Analysis of Primary Neoplasms in Female Rats in the 2-Year Feed Study of Methylphenidate Hydrochloride 

TABLE B3 

Fisher exact test 

Cochran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

Thyroid Gland (Csell): Adenoma or Carcinoma 

Fisher exact test 

Cochran-hitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

Uterus: Stromal Polyp 

P=0.364N 

P=0.334N P=O.O85 P=O.276 P=O.516 

P=0.228N P=O.O94 P=O.337 P=O.603 

649 660 730 

u31(6%) 8/32 (25%) 6/36 (17%) 

10.8% 28.5% 18.9% 12.4% 

4/50 (8%) 10/50 (20%) 7/50 (14%) 

P=O.O74 P=O.262 P=O.500 

4/39 (10%) 

5/50 (10%) 

5/50 (10%) 

P=O.510 

P=O.514 P=O.195 P=O.384 P=O.414 

P=0.436N P=O.236 P=O.477 P=O.522 

668 494 466 619 

4/31 (13%) 4/32 (13%) 5/36 (14%) 5/39 (13%)

15.2% 22.8% 17.9% 16.9% 

9/50 (18%) 7/50 (14%) 7/50 (14%) 

P=O.194 P=O.380 P=O.380 

, Uterus: Stromal Polyp or Stromal Sarcoma 

Fisher exact test 

Cochran-+itage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

P=0.490N 

P=0.492N 

P=0.340N 

551 

4/31 (13%) 

18.7% 

7/50 (14%) 10/50 (20%) 7/50 (14%) 8/50 (16%) 

25.5% 17.9% 19.3% 

5/32 (16%) 5/36 (14%) 6/39 (15%) 

494 466 619 

P=O.344 P=0.527N P=0:578N 

P=O.274 P=O.612 P=O.501 

P=O.298 P=0.613N P=O.500 

' All Organs: Mononuclear Cell Leukemia 

Fisher exact test 

Cochran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

P=0.508N 

P=O.435 P=O.301 P=O.497 P=O.229 

P=0.341N P=O.559 P=0.567N P=0.437N 

575 488 425 

3/31 (10%)8/32 (25%)8/36 (22%) 8/39 (21%) 

30.0% 35.1% 32.6% 29.5% 

13/50 (26%) 14/50 (28%) 14/50 (28%) 13/50 (26%) 

P=O.500 P=O.500 P=0.590N 

Fisher yct test 

Cochran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

All Organs: Benign Neoplasms 

40/50 (80%) 44/50 (88%) 37/50 (74%) 35/50 (70%) 

92.9% 93.5% 85.9% 79.4% 

P=0.033N 

P=O.O24N P=O.261 P=0.309N P=0.126N 

P=O.O02N P=O.430 P=0.099N P=0.016N 

450 450 466 

29/32 (91%) 30/36 (83%) 0/39 (77%) 

P=O.207 P=0.318N P=0.178N 

28/31 (90%) 
Lesions in Female Rats 139 

(continued) 

Statistical Analysis of Primacy Neoplasms in Female Rats in the 2-Year Feed Study of Methylphenidate Hydrochloride 

TABLE B3 

Fisher exact test 

Cochran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

All Organs: Malignant Neoplasms 

Fisher exact test 

Cochran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

All Organs: Benign or Malignant Neoplasms 

P=0.260N 

P=0.405N 

P=0.139N 

551 

6/31 (19%) 

41.8% 

19/50 (38%) 

P=O.O7ON 

P=0.065N 

P-0.016N 

450 

29/31 (94%) 

95.9% 

47/50 (94%) 

P=O.179 

P=O.437 

488 

13/32 (41%) 

52.4% 

22/50 (44%) 

P=O.342 

P=0.621N 

P=0.418N 

450 

29/32 (91%) 

94.0% 

47/50 (94%) 

P=0.661N 

44.9% 

20/50 (40%) 

P=O.318 

P=O.SU)N 

425 

12/36 (33%) 

P=O.500 

P=0.357N 

P=O.l56N 

425 

32/36 (89%) 

91.8% 

45/50 (90%) 

P=O.357N 

36.9% 

17/50 (34%) 

P=O.489 

P=0.275N 

442 

10/39 (26%) 

P=O.418N 

87.7% 

43/50 (86%) 

P=O.l36N 

P = 0.033N 

404 

33/39 (85%) 

P=0.159N 

a Number of neoplasm-bearing animals/number of animals examined. Denominator is number of animals examined microscopically for adrenal gland, 

(T)Terminal sacrifice 

exact tests compare directly the overall incidence rates. For all tests, a negative trend or a lower incidence in an exposure group is indicated by N. 

as being (directly or indirectly) the cause of death. The logistic regression test regards these lesions as nonfatal. The Cochran-Armitage and Fisher 

to pairwise comparisons between the controls and that exposed group. The life table test regards neoplasms in animals dying prior to terminal kill 

Beneath the control incidence are the P values associated with the trend test. Beneath the exposed group incidence are the P values corresponding 

Observed incidence at terminal kill 

Kaplan-Meier estimated neoplasm incidence at the end of the study after adjustment for intercurrent mortality 

pituitary gland, thyroid gland, and uterus; for other tissues, denominator is number of animals necropsied. 
140 Methylphenidate Hydrochloride, NTP TR 439 

Historical Incidence of Mammary Gland Fibroadenomas in Untreated Female F344M Rats' 

TABLE B4 

Study Incidence in Controls 

Historical Incidence at TSI Mason Research Institute 

Turmeric oleoresin 

Quercetin 

Pentaerythritol tetranitrate 

HC Yellow 4 

Acetaminophen 

l-Amino-2,4-dibromoanthraquinone 

Overall Historical Incidence 

Range 

Standard deviation 

Total 

13/50 

29/50 

27\50 

28/50 

19/50 

21/50 

8%-58% 

13.5% 

484/1,251(38.7%) 

a Data as of 20 August 1992 
Lesions in Female Rats 141 

of Methylphenidate Hydrochloride' 

Summary of the Incidence of Nonneoplastic Lesions in Female Rats in the 2-Year Feed Study 

TABLE B5 

Early deaths 

ZS-MO?ldl intaim CvalLmiopr 

PMO?ldlintaimt!dUth 

Animals initially in study 

Disposition Summary 

Terminal sacrifice 

Died last week of study 

Natural deaths 

Moribund 

Survivors 

10 

10 

70 

10 

10 

70 

10 

10 

70 

10 

10 

70 

4 

7 

6 

13 

6 

12 

4 

10 

29 

2 

30 

2 

38 

1 

36 

Animals examined microscopically 70 70 70 70 

Intestine large, colon 

Alimentary System 

9-Month Interim Evaluation 

Parasite metazoan 

Intestine small, ileum 

Parasite metazoan 

Intestine large, cecum 

Parasite metazoan 

Intestine large, rectum 

Parasite metazoan 

Bile duct, hyperplasia 

Hepatodiaphragmatic nodule 

Granuloma 

Basophilic focus 

Liver 

Acinus, atrophy 

Inflammation, chronic, focal 

Fat, necrosis 

Pancreas 

Mesentery 

1 (10%) 

(10) 

(1) 

1 (100%) 

1 (10%) 

(10) 

1 (10%) 

2 (20%) 

Heart 

Cardiovascular System 

Inflammation, chronic, focal 

Hypoplasia 

Islets, pancreatic 

Endocrine System 

Pars distalis, hyperplasia, focal 

Pars distalis, cyst 

Pituitary gland 

Inflammation, chronic, focal 

Thyroid gland 

a Number of animals examined microscopically at site and number of animals with lesion 
142 Methylphenidate Hydrochloride, NTP TR 439 

of Methylphenidate Hydrochloride (continued) 

Summary of the Incidence of Nonneoplastic Lesions in Female Rats in the 2-Year Feed Study 

TABLE B5 

0 PPm 100 ppm SO0 ppm 1,000 ppm 

None 

General Body System 

9-Month Interim Evaluation (continued) 

Inflammation, chronic, focal 

AbScesS 

Clitoral gland 

Genital System 

Cyst 

ovary 

Cyst 

Uterus 

Dilatation 

Lymph node 

Bone marrow 

Hematopoietic System 

Pancreatic, pigmentation, hemosiderin 

Pancreatic, giant cell 

Myelofibrosis 

Giant cell 

Congestion 

Lymph node, mandibular 

Giant cell 

Lymph node, mesenteric 

None 

Integumentary System 

None 

Musculoskeletal System 

Brain 

Nervous System 

(10) 

Choroid plexus, inflammation, chronic 

Lung 

Respiratory System 

(10) (10) (10) (10) 

Metaplasia, squamous 

Inflammation, chronic, focal 

Peribronchial, inflammation, chronic 

Granuloma 

2 (20%) 1 (10%) 1 (10%) 

10 (100%) 10 (100%) 9 (100%) 8 (80%) 

10 (100%) 10 (100%) 10 (100%) 

1 (10%) 

9 (90%) 

Nose (10) (10) (9) (10) 
Lesions in Female Rats 143 

of Methylphenidate Hydrochloride (continued) 

Summary of the Incidence of Nonneoplastic Lesions in Female Rats in the 2-Year Feed Study 

TABLE B5 

~~ 

100 ppm 500 PPm 1,000 ppm 

None 

Special Senses System 

9-Month Interim Evaluation (continued) 

Kidney 

Urinary System 

Renal tubule, regeneration 

Nephropathy 

Mineralization, focal 

(10) (10) (10) (10) 

1 (10%) 2 (20%) 1 (10%) 

1 (10%) 

2 (20%) 5 (50%) 7 (70%) 

2 (20%) 

15-Month Interim Evaluation 

Parasite metazoan 

Intestine large, colon 

Alimentary System 

Parasite metazoan 

Intestine large, cecum 

Parasite metazoan 

Intestine large, rectum 

Bile duct, hyperplasia 

Hepatodiaphragmatic nodule 

Granuloma 

Developmental malformation 

Clear cell focus 

Basophilic focus 

Angiectasis, focal 

Liver 

Inflammation, chronic, focal 

Acinus, atrophy . 

(10) 

(10) 

(10) 

(10) 

(10) 

(10) 

(10) 

(10) 

(10) 

(10) 

(10) 

(10) 

(10) 

(10) 

(10) 

(10) 

3 (30%) 

2 (20%) 3 (30%) 

1 (10%) 

1 (10%) 

2 (20%) 1 (10%) 4 (40%) 

2 (20%) 

7 (70%) 9 (90%) 5 (50%) 7 (70%) 

1 (10%) 

1 (10%) 

1 (10%) 4 (40%) 

1 (10%) 

2 (20%) 2 (20%) 

1 (10%) 

1 (10%) 2 (20%) 1 (10%) 

1 (10%) 

2 (20%) 

3 (30%) 

Salivary glands 

Pancreas 

(10) 

(10) 

(10) 

(10) 

(10) 

(10) 

(10) 

(10) 

1 (10%) 

Heart 

Cardiovascular System 

(10) (10) (10) (10) 

Myocardium, inflammation, chronic, focal 

Coronary artery, inflammation, chronic 

Cardiomyopathy 3 (30%) 

2 (20%) 

1 (10%) 

1 (10%) 1 (10%) 

1 (10%) 

Congestion 

Adrenal cortex 

Endocrine System 

Hyperplasia, focal 

Adrenal medulla 

Pars distalis, hyperplasia, focal 

Pars distalis, hyperplasia 

Pars distalis, cyst 

Pars distalis, angiectasis, focal 

Pars distalis, angiectasis 

Pituitaxy gland 
144 Methylphenidate Hydrochloride, NTP TR 439 

of Methylphenidate Hydrochloride (continued) 

Summary of the Incidence of Nonneoplastic Lesions in Female Rats in the 2-Year Feed Study 

TABLE B5 

0 PPm 100 PPm 500 ppm 1,000 ppm 

Thyroid gland 

Endocrine System (continued) 

15-Month Interim Evaluation (continued) 

(10) (10) (10) (10) Cell, hyperplasia 2 (20%) 3 (30%) 2 (20%) 

None 

General Body System 

Genital System 

Inflammation, chronic 

Dilatation 

AbSceSS 

Clitoral gland 

Endometrium, fibrosis 

Dilatation 

Inflammation, chronic, focal 

ovary 

Uterus 

Lymph node 

Hematopoietic System 

Mediastinal, congestion 

Cyst 

Thymus (8) 

1 (13%) 

None 

Integumentary System 

None 

Musculoskeletal System 

Brain 

Nervous System 

Capillary, inflammation, chronic 

(10) 

2 (20%) 

Nose 

Respiratory System 

Metaplasia, squamous 

Inflammation, chronic 

Inflammation, acute 

Fungus 

(10) 

1 (10%) 

9 (90%) 

1 (10%) 

1 (10%) 

10 (100%) 10 (100%) 

1 (10%) 1 (10%) 

8 (80%) 

Harderian gland 

Special Senses System 

Hyperplasia 

(1) 

1 (100%) 
Lesions in Female Rats 145 

of Methylphenidate Hydrochloride (continued) 

Summary of the Incidence of N~~e~plastic Lesions in Female Rats in the 2-Year Feed Study 

TABLE B5 

0 PPm 100 ppm 500 ppm 1,000 ppm 

Kidney 

Urinary System 

15-Month Interim Evaluation (continued) 

Inflammation, chronic, focal 

Urinary bladder 

Nephropathy 

(10) 

(10) 

(10) 

(10) 

(10) 

(10) 

(10) 

(10) 

1 (10%) 

8 (80%) 7 (70%) 6 (60%) 7 (70%) 

1 (10%) 

2-Year Study 

Intestine large, colon 

Angiectasis 

Esophagus 

Mimentary System 

Intestine large, cecum 

Parasite metazoan 

Intestine large, rectum 

Parasite metazoan 

Parasite metazoan 

'Inflammation, chronic 

Dilatation 

Autolysis 

Abscess 

Intestine small, ileum 

Bile duct, hyperplasia 

Pigmentation, bile 

Necrosis, focal 

Mineralization, focal 

Hepatodiaphragmatic nodule, multiple 

Hepatodiaphragmatic nodule 

Hemorrhage 

Granuloma 

Fatty change 

Eosinophilic focus 

Developmental malformation 

Depletion glycogen 

Clear cell focus 

Basophilic focus 

Atrophy 

Angiectasis 

Abscess 

Liver 

Fat, necrosis 

Inflammation, granulomatous 

Accessory spleen 

Artery, inflammation, chronic 

Acinus, hyperplasia, focal 

Acinus, atrophy 

Ectopic liver 

Mesentery 

Pancreas 

(46) 

(49) 

(47) 

(50) 

5 (11%) 

4 (8%) 

1 (2%) 

1 (2%) 

3 (7%) 

(50) 

(46) 

1 (2%) 

2 (4%) 

35 (70%) 

1 (2%) 

10 (20%) 

6 (12%) 

3 (6%) 

8 (16%) 

1 (2%) 

1 (2%) 

1 (2%) 

1 (2%) 

(4) 

11 (22%) 

(45) 

(47) 

(47) 

(50) 

1 (2%) 

3 (6%) 

2 (4%) 

1 (2%) 

1 (2%) 

8 (16%) 

39 (78%) 

6 (12%) 

3 (6%) 

1 (2%) 

2 (4%) 

5 (10%) 

(6) 

5 (83%) 

1 (17%) 

(49) 

1 (2%) 

1 (2%) 

9 (18%) 

2 (4%) 

2 (4%) 

(50) 

(47) 

4 (8%) 

36 (72%) 

4 (8%) 

1 (2%) 

5 (10%) 

1 (2%) 

4 (8%) 

8 (89%) 

(50) 

15 (30%) 

(48) 

(50) 

(49) 

(49) 

1 (2%) 

3 (6%) 

1 (2%) 

1 (2%) 

5 (10%) 

1 (2%) 

(50) 

(48) 

4 (8%) 

39 (78%) 

10 (20%) 

7 (14%) 

4 (8%) 

6 (12%) 

1 (2%) 

1 (2%) 

1 (2%) 

(3) 

1 (33%) 

2 (67%) 

(50) 

11 (22%) 
146 Methylphenidate Hydrochloride, NTP TR 439 

Of Methylphenidate Hydrochloride (continued) 

Summary of the Incidence of Nonneoplastic Lesions in Female Rats in the &Year Feed Study 

TABLE B5 

0 PPm 100 ppm 500 ppm 1,000 ppm 

2-Year Study (continued) 

Alimentary System (continued) 

Inflammation, chronic, focal 

Hypoplasia 

Hyperplasia 

Depletion cellular 

Salivary glands 

Ulcer 

Inflammation, subacute 

Hyperplasia, squamous 

Hyperkeratosis 

Diverticulum 

Acanthosis 

Ulcer 

Hypoplasia 

Erosion 

Edema, focal 

Depletion cellular 

Stomach, glandular 

Stomach, forestomach 

(50) 

1 (2%) 

1 (2%) 

2 (4%) 

1 (2%) 

(49) 

1 (2%) 

2 (4%) 

1 (2%) 

(50) 

1 (2%) 

5 (10%) 

1 (2%) 

1 (2%) 

1 (2%) 

(49) 

8 (16%) 

(50) 

1 (2%) 

(50) 

(50) 

1 (2%) 

1 (2%) 

1 (2%) 

1 (2%) 

(50) (50) 

5 (10%) 

1 (2%) 

1 (2%) 

3 (6%) 

1 (2%) 

Heart 

Cardiovascular System 

Perivascular, inflammation 

Artery, mineralization 

Pigmentation 

Mineralization 

Dilatation 

Cardiomyopathy 

(50) 

1 (2%) 

22 (44%) . (50) (50) (50) 22 (44%) 23 (46%) 26 (52%) 

1 (2%) 

1 (2%) 

1 (2%) 

1 (2%) 

1 (2%) 

Endocrine System 

Vacuolization cytoplasmic 

Mineralization, focal 

Hyperplasia, focal 

Cytoplasmic alteration, focal 

Atrophy 

Adrenal cortex 

Necrosis 

Hyperplasia, focal 

Fibrosis 

Hypoplasia 

Hyperplasia 

Islets, pancreatic 

Hyperplasia, focal 

Hyperplasia 

Parathyroid gland 

Adrenal medulla 

(50) 

3 (6%) 

1 (2%) 

3 (6%) 

(50) 

7 (14%) 

(50) 

(47) 

2 (4%) 

(49) 

8 (16%) 

(49) 

1 (2%) 

3 (6%) 

(49) 

1 (2%) 

1 (2%) 

1 (2%) 

1 (2%) 

(46) 

(50) 

3 (6%) 

8 (16%) 

2 (4%) 

(50) 

3 (6%) 

(50) 

(49) 

1 (2%) 

3 (6%) 

2 (4%) 

1 (2%) 

(50) 
Lesions in Female Rats 147 

of Methylphenidate Hydrochloride (continued) 

Summary of the Incidence of Nonneoplastic Lesions in Female Rats in the 2-Year Feed Study 

TABLE B5 

&Year Study (continued) 

Pituitary gland 

Endocrine System (continued) 

Pars distalis, hyperplasia, focal 

Pars distalis, cyst 

Pars distalis, angiectasis 

Hemorrhage 

Cell, hyperplasia 

Thyroid gland 

(50) (49) (50) (49) 

1 (2%) 

2 (4%) 

2 (4%) 

1 (2%) 

7 (14%) 

4 (8%) 

12 (24%) 9 (18%) 12 (24%) 12 (24%) 

12 (24%) 12 (24%) 10 (20%) 

5 (10%) 

1 (2%) 1 (2%) 

6 (12%) 

13 (27%) 

(50) (50) (50) (50) 

None 

General Body System 

AbScesS 

Clitoral gland 

Genital System 

Inflammation, chronic 

Inflammation, acute 

Dilatation 

Depletion cellular 

Atrophy 

Angiectasis 

Cyst 

ovary 

Cyst 

Uterus 

Atrophy 

Angiectasis 

Abscess 

Endometrium, hyperplasia, cystic 

Endometrium, fibrosis 

Endometrium, cyst 

Thrombosis 

Dilatation 

Ewdate 

Dilatation 

Cyst 

Vagina 

(45) 

4 (9%) 

5 (11%) 

4 (9%) 

9 (20%) 

(50) 

1 (2%) 

1 (2%) 

(50) 

1 (100%) 

2 (4%) 

(1) 

(4) 

2 (4%) 

2 (4%) 

2 (4%) 

2 (4%) 

4 (8%) 

4 (8%) 

(50) 

4 (8%) 

1 (2%) 

2 (4%) 

(1) 

1 (100%) 

(49) 

3 (6%) 

5 (10%) 

1 (2%) 

4 (8%) 

1 (2%) 

5 (10%) 

(50) 

(50) 

1 (2%) 

1 (2%) 

3 (6%) 

1 (25%) 

1 (25%) 

1 (2%) 

2 (4%) 

1 (2%) 

(4) 

(49) 

2 (4%) 

9 (18%) 

2 (4%) 

2 (4%) 

2 (4%) 

1 (2%) 

1 (2%) 

(50) 

(50) 

2 (4%) 

2 (4%) 

1 (2%) 

1 (2%) 

5 (10%) 

Blood 

Hematopoietic System 

Hypochromasia 

Bacterium 

Myelofibrosis 

Hyperplasia 

Bone marrow 
148 Methylphenidate Hydrochloride, NTP TR 439 

of Methylphenidate Hydrochloride (continued) 

Summary of the Incidence of Nonneoplastic Lesions in FemaIe Rats in the 2-Year Feed Study 

TABLE B5 

Lymph node 

Hematopoietic System (continued) 

2-Year Study (continued) 

Pancreatic, lymphatic, angiectasis 

Pancreatic, infiltration cellular, histiocyte 

Pancreatic, granuloma 

Pancreatic, congestion 

Pancreatic, angiectasis 

Mediastinal, lymphatic, angiectasis 

Mediastinal, hematopoietic cell proliferation 

Mediastinal, congestion 

Mediastinal, angiectasis 

Lumbar, hyperplasia 

Lumbar, congestion 

Inguinal, congestion 

Congestion 

Lymphatic, angiectasis 

Inflammation, acute 

Infiltration cellular, histiocyte 

Infiltration cellular, plasma cell 

Granuloma 

Giant cell 

Depletion lymphoid 

Congestion 

Lymph node, mesenteric 

Capsule, fibrosis 

Pigmentation, hemosiderin 

Necrosis, focal 

Infarct 

Hematopoietic cell proliferation 

Granuloma 

Fibrosis, focal 

Depletion lymphoid 

Congestion 

Autolysis 

Lymph node, mandibular 

Cyst 

Spleen 

Cyst 

Thymus 

Lymphatic, angiectasis 

Hyperplasia 

Depletion lymphoid 

(8) 

1 (13%) 

1 (13%) 

(50) 

1 (2%) 

1 (2%) 

1 (2%) 

(50) 

3 (6%) 

1 (2%) 

1 (2%) 

1 (2%) 

1 (2%) 

1 (2%) 

1 (2%) 

1 (2%) 

1 (2%) 

1 (2%) 

1 (2%) 

(50) 

4 (8%) 

4 (8%) 

(48) 

2 (4%) 

(6) 

1 (17%) 

1 (17%) 

(50) 

1 (2%) 

1 (2%) 

(49) 

1 (2%) 

1 (2%) 

2 (4%) 

1 (2%) 

(48) 

1 (2%) 

2 (4%) 

(11) 

1 (9%) 

1 (9%) 

1 (9%) 

1 (9%) 

1 (9%) 

1 (2%) 

1 (2%) 

1 (9%) 

1 (9%) 

(50) 

1 (2%) 

(50) 

3 (6%) 

(50) 

4 (8%) 

3 (6%) 

6 (12%) 

1 (2%) 

1 (2%) 

(50) 

1 (2%) 

1 (2%) 

(6) 

1 (17%) 

1 (17%) 

1 (17%) 

1 (17%) 

1 (17%) 

1 (2%) 

2 (4%) 

2 (33%) 

2 (4%) 

1 (2%) 

(49) 

(50) 

4 (8%) 

1 (2%) 

1 (2%) 

(50) 

9 (18%) 

1 (2%) 

3 (6%) 

1 (2%) 

2 (4%) 

1 (2%) 

(47) 

Mammary gland 

Integumentary System 

(49) (50) (48) (50) 

Lactation 

Galactocele, multiple 

Galactocele 

35 (71%) 

9 (18%) 

1 (2%) 

5 (10%) 2 (4%) 1 (2%) 

1 (2%) 

36 (72%) 27 (56%) 25 (50%) 
Lesions in Female Rats 149 

of Methylphenidate Hydrochloride (continued) 

Summary of the Incidence of Nonneoplastic Lesions in Female Rats in the 2-Year Feed Study 

TABLE B5 

0 PPm 100 PPm 500 PPm 1,000 ppm 

2-Year Study (continued) 

Skin 

Integumentary System (continued) 

Perivascular, inflammation, chronic 

Hyperkeratosis 

Fibrosis 

Cyst epithelial inclusion 

Acanthosis (50) (50) (50) 

1 (2%) 

1 (2%) 

1 (2%) 

1 (2%) 

1 (2%) 

1 (2%) 

Bone 

Musculoskeletal System 

Ectopic tissue 

Skeletal muscle 

Hyperostosis 

Brain 

Nervous System 

Hemorrhage 

Congestion 

Compression 

Abscess (49) 

4 (8%) 

6 (12%) 4 (8%) 

2 (4%) 

(50) 

1 (2%) 

4 (8%) 

4 (8%) 

Lung 

Respiratory System 

Pleura, fibrosis, focal 

Alveolar epithelium, metaplasia 

Necrosis, focal 

Mineralization, focal 

Hemorrhage, focal 

Emphysema, focal 

Congestion 

Angiectasis 

Inflammation, chronic 

Inflammation, acute 

Fungus 

Nose (50) 

3 (6%) 

1 (2%) 

1 (2%) 

(50) (50) (50) 

1 (2%) 

1 (2%) 

1 (2%) 

2 (4%) 2 (4%) 

1 (2%) 

1 (2%) 

1 (2%) 

1 (2%) 

(50) (50) (50) 

4 (8%) 

6 (12%) 

4 (8%) 

3 (6%) 2 (4%) 

2 (4%) 

1 (2%) 

6 (12%) 

9 (18%) 

Eye 

Special Senses System 

Retina, degeneration 

Cataract 

(2) 

1 (50%) 
150 Methylphenidate Hydrochloride, NTP TR 439 

of Methylphenidate Hydrochloride (continued) 

Summary of the Incidence of Nonneoplastic Lesions in Female Rats in the 2-Year Feed Study 

TABLE B5 

Kidney 

Urinary System 

&Year Study (continued) 

Bacterium 

AbSCeSS 

Renal tubule, pigmentation, bile 

Renal tubule, necrosis, focal 

Renal tubule, degeneration, granular 

Pigmentation 

Nephropathy 

Mineralization 

Glomerulosclerosis 

Hyperplasia, focal 

Hemorrhage 

Urinary bladder 

Cyst 1 (2%) 

37 (74%) 

19 (38%) 22 (45%) 

2 (4%) 

1 (2%) 

1 (2%) 

42 (86%) 

1 (2%) 

4 (8%) 6 (12%) 

(47) (44) 

1 (2%) 
151 

OF METHYLPHENIDATE HYDROCHLORIDE 

SUMMARY OF LESIONS IN MALE MICE 

APPENDIX C 

IN THE 2-YEAR FEED STUDY 

TABLE C3 Statistical Analysis of Primary Neoplasms in Male Mice 

in the 2-Year Feed Study of Methylphenidate Hydrochloride 

TABLE C2 Individual Animal Tumor Pathology of Male Mice 

in the 2-Year Feed Study of Methylphenidate Hydrochloride 

TABLE C1 Summary of the Incidence of Neoplasms in Male Mice 

TABLE C5 Summary of the Incidence of Nonneoplastic Lesions in Male Mice 

TABLE C4 Historical Incidence of Liver Neoplasms in Untreated Male B6C3Fl Mice 

in the 2-Year Feed Study of Methylphenidate Hydrochloride 

in the 2-Year Feed Study of Methylphenidate Hydrochloride 

.................... 

176 

156 

152 

181 

180 

.................... 

.................... .......... 

.................... 
152 Methylphenidate Hydrochloride, NTP TR 439 

0 PPm 50 PPm 250 ppm 500 ppm 

Early deaths 

IS-M& intaim emhtian 

PManrlrintaimCb"## 

Animals initially in study 

Disposition Summary 

Terminal sacrifice 

Died last week of study 

Natural deaths 

Moribund 

SuMvors 

10 

10 

70 

3 

2 

45 

10 

10 

70 

3 

2 

45 

10 

10 

70 

2 

4 

43 

1 

10 

10 

70 

-5 

4 

41 

Animals examined microscopically 70 70 70 70 

9-Month Interim Evaluation 

Liver 

Alimentary Systemb 

(10) 

Hepatocellular adenoma 

15-Month Interim Evaluation 

Liver 

Alimentary System' 

(10) (10) 

Hepatocellular adenoma, multiple 

Hepatocellular adenoma 

Hepatocellular carcinoma 

2 (20%) 

(10) (10) 

1 (10%) . 

1 (10%) 

1 (10%) 

1 (10%) 

Lung 

Respiratory System 

Alveolarbronchiolar adenoma 

Intestine small, ileum 

Intestine small, jejunum 

Intestine small, duodenum 

Intestine large, cecum 

Alimentary System 

2-Year Study 

Liver 

Sarcoma 

Sarcoma 

Histiocytic sarcoma 

Hepatocellular adenoma, multiple 

Hepatocellular adenoma 

Hepatocellular carcinoma, multiple 

Hepatocellular carcinoma 

Hepatoblastoma, multiple 

Hepatoblastoma 

Hemangiosarcoma 

Hemangioma 

Sarcoma 

Hepatoblastoma, metastatic, liver 

Mesentery 

13 (26%) . 

8 (16%) 

5 (10%) 

2 (4%) 

8 (16%) 

8 (16%) 

1 (2%) 

(3) 

1 (2%) 

1 (2%) 

10 (20%) 

1 (33%) 

(48) 

(47) 

(48) 

(48) 

(50) 

1 (2%) 

2 (4%) 

1 (2%) 

1 (2%) 

,10 (20%) 

15 (30%) 

6 (12%) 

4 (8%) 

1 (2%) 

14 (28%) 

15 (30%) 

1 (2%) 

10 (20%) 

1 (2%) 

(2) 

1 (50%) 
Lesions in Male Mice 153 

(continued) 

Summary of the Incidence of Neoplasms in Male Mice in the 2-Year Feed Study of Methylphenidate Hydrochloride 

TABLE C1 

2-Yeur Study (continued) 

Pancreas 

Alimentary System (continued) 

Hemangiosarcoma, metastatic, spleen 

Stomach, forestomach 

Salivary glands 

Sarcoma 

Tongue 

Stomach, glandular 

Squamous cell papilloma 

Sarcoma 

Squamous cell papilloma 

Heart 

Cardiovascular System 

(50) 

Hemangiosarcoma 

Adenocarcinoma, metastatic, prostate 

Endocrine System 

Capsule, adenoma 

Adenoma 

Adrenal cortex 

Adenoma 

Islets, pancreatic 

Pheochromocytoma benign 

Adrenal medulla 

Pars intennedia, carcinoma 

Pars intermedia, adenoma 

Pituitary gland 

Follicular cell, adenoma 

Thyroid gland 

None 

General Body System 

Prostate 

Epididymis 

Genital System 

Adenocarcinoma 

Sarcoma 

Seminal vesicle 

Sarcoma 

Interstitial cell, adenoma 

Testes 

Hematopoietic System 

Mast cell tumor NOS 

Histiocytic sarcoma 

Hemangiosarcoma 

Bone marrow 
154 Methylphenidate Hydrochloride, NTP TR 439 

(continued) 

Summary of the Incidence of Neoplasms in Male Mice in the 2-Year Feed Study of Methylphenidate Hydrochloride 

TABLE C1 

0 PPm 50 PPm 250 ppm 500 ppm 

Lymph node 

Hematopoietic System (continued) 

%Year Study (continued) 

Pancreatic, sarcoma 

Mediastinal, sarcoma 

Mediastinal, histiocytic sarcoma 

Histiocytic sarcoma 

Lymph node, mesenteric 

Lymph node, mandibular 

Sarcoma 

Sarcoma 

Mast cell tumor NOS 

Histiocytic sarcoma 

Hemangiosarcoma 

Sarcoma 

Spleen 

Thymus 

(5) 

1 (20%) 

1 (2%) 

1 (2%) 

(41) 

Skin 

Integumentary System 

Sarcoma 

Lipoma 

Hemangiosarcoma 

Fibroma 

1 (2%) 

2 (4%) 

(50) 

1 (2%) 

1 (2%) 

None 

Musculoskeletal System 

Brain 

Nervous System 

Carcinoma, metastatic, pituitary gland 

Lung 

Respiratory System 

(50) 

Sarcoma, metastatic, mesentery 

Sarcoma 

Histiocytic sarcoma 

Hepatocellular carcinoma, metastatic, liver 

Hepatoblastoma, metastatic, liver 

Carcinoma, metastatic, harderian gland 

Alveolarbronchiolar carcinoma 

Alveolarbronchiolar adenoma, multiple 

Alveolarbronchiolar adenoma 

Adenocarcinoma, metastatic, prostate 

4 (8%) 

13 (26%) 

4 (8%) 

1 (2%) 

1 (2%) 

Nose (50) 

(50) (50) 

1 (2%) 

6 (12%) 

5 (10%) 2 (4%) 

2 (4%) 

5 (10%) 

4 (8%) 

1 (2%) 

1 (2%) 

1 (2%) 

(50) (50) 

(50) 

5 (10%) 

1 (2%) 

1 (2%) 

1 (2%) 

1 (2%) 

Special Senses System 

Carcinoma 

Adenoma 

Harderian gland (5) (2) 

4 (80%) 1 (50%) 

1 (20%) 

(2) 

1 (50%) 

1 (50%) 
Lesions in Male Mice 155 

(continued) 

Summary of the Incidence of Neoplasms in Male Mice in the 2-Year Feed Study of Methylphenidate Hydrochloride 

TABLE C1 

0 PPm 50 PPm 250 ppm 

Kidney 

Urinary System 

&Year Study (continued) 

Urinary bladder 

Histiocytic sarcoma 

Multiple organsd 

Systemic Lesions 

Lymphoma malignant mixed 

Lymphoma malignant lymphocytic 

Histiocytic Sarcoma 

(50) (50) (50) (50) 

1 (2%) 

1 (2%) 

1 (2%) 

1 (2%) 

3 (6%) 4 (8%) 3 (6%) 8 (16%) 

Total animals with primary neoplasmse 

Neoplasm Summary 

2-Year study 

15-Month interim evaluation 

9-Month interim evaluation 

2-Year study 

15-Month interim evaluation 

9-Month interim evaluation 

2-Year study 

15-Month interim evaluation 

9-Month interim evaluation 

2-Year study 

15-Month interim evaluation 

9-Month interim evaluation 

15-Month interim evaluation 

2-Year study 

15-Month interim evaluation 

2-Year study 

2-Year study 

2-Year study 

Total primary neoplasms 

Total animals with benign neoplasms 

Total benign neoplasms 

Total animals with malignant neoplasms 

Total malignant neoplasms 

Total animals with uncertain neoplasms 

Total metastatic neoplasms 

Total animals with metastatic neoplasms 

benign or malignant 

2-Year study 

2-Year study 

Total uncertain neoplasms 

33 

1 

1 

41 

2 

43 

3 

35 

1 

56 

,1 

1 

67 

2 

72 

1 

74 

3 

23 

1 

1 

31 

2 

23 

1 

33 

2 

29 

1 

1 

43 

2 

38 

2 

30 

1 

24 

1 

19 24 22 

34 

1 

5 

5 

24 

3 

2 

42 27 

5 4 

5 4 

1 

2 

Number of animals with any tissue examined microscopically 

No neoplasms were observed at any other site in any animal at the 15-month interim evaluation. 

No neoplasms were observed at any other site in any animal at the 9-month interim evaluation. 

Number of animals examined microscopically at site and number of animals with neoplasm 

e Primary neoplasms: all neoplasms except metastatic neoplasms 
156 Methylphenidate Hydrochloride, NTP TR 439 

5666677777777777777777777 

Number of Days on Study 

7790911111111111111111~111 

3134144444444444444444444 

6077012359457890123457923 

1606100000111112222222233 

0000000000000000000000000 

Carcass ID Number 

Liver 

Intestine small, ileum 

Intestine small, jejunum 

Intestine small, duodenum 

Intestine large, cecum 

Intestine large, rectum 

Intestine large, colon 

Gallbladder 

Esophagus 

Alimentary System 

Hepatocellular adenoma, multiple 

Hepatocellular adenoma 

Hepatocellular carcinoma, multiple 

Hepatocellular carcinoma 

Hemangiosarcoma 

Stomach, forestomach 

Salivary glands 

Pancreas 

Mesentery 

Tongue 

Stomach, glandular 

Squamous cell papilloma 

Squamous cell papilloma 

......................... 

A++A+++++M+++++++++++++++ 

......................... 

......................... 

......................... 

......................... 

A++A++++++++++++++++++++M 

M++AM+++++++++++M++++++++ 

......................... 

xxx 

+ 

xx 

X xxx xx xx xx 

.......................... 

......................... 

......................... 

......................... 

X 

+ 

Cardiovascular System 

Heart ......................... 

Endocrine System 

Capsule, adenoma 

Adenoma 

Adrenal cortex 

Islets, pancreatic 

Pheochromocytoma benign 

Adrenal medulla 

Thyroid gland 

Pituitary gland 

Parathyroid gland 

Adenoma 

Follicular cell, adenoma 

+M+++++++++++++++++++++++ 

+M+M+++++++++++++++++++++ 

......................... 

......................... 

M++++++++++++++++++++++++ 

+++M+++++++M+++++++M+++M+ 

General Body System 

None 

Genital System 

Testes 

Seminal vesicle 

Prostate 

Preputial gland 

Epididymis 

......................... 

......................... 

......................... 

......................... 

......................... 

A: Autolysis precludes examination 

+: Tissue examined microscopically 

I: Insufficient tissue 

M: Missing tissue 

Blank Not examined 

X. Lesion present 
Lesions in Male Mice 157 

(continued) 

Individual Animal Tumor Pathology of Male Mice in the 2-Year Feed Study of Methylphenidate Hydrochloride: 0 ppm 

TABLE C2 

Number of Days on Study 

1111111111111111111111111 

4444444444444444444444444 

11111111111171111111,11111 

0000000,000000000000000000 

6890234518913451891234689 Tumors 

3334444444455555556666666 Tissues/ 

Total 

Carcass ID Number 

Liver 

Intestine small, ileum 

Intestine small, jejunum 

Intestine small, duodenum 

Intestine large, cecum 

Intestine large, rectum 

Intestine large, colon 

Gallbladder 

Esophagus 

Alimentary System 

Hepatocellular adenoma, multiple 

Hepatocellular adenoma 

Hepatocellular carcinoma, multiple 

Hepatocellular carcinoma 

Hemangiosarcoma 

+++++++++++M+++++++++++++ 49 

......................... 46 

......................... 41 

......................... 50 

......................... 41 

......................... 48 

......................... 48 

......................... 48 

' ......................... 49 

1 

5 

13 

2 

8 

X X X 3 

......................... 50 

X 

xx 

xxxx 

xx 

X X 

X 

X 

Pancreas 

Mesentery 

Tongue 

Stomach, glandular 

Stomach, forestomach 

Salivary glands 

Squamous cell papilloma 

......................... 50 

......................... 49 

X 1 

.......................... 48 

+ +< 3 

Squamous cell papilloma 1 

Cardiovascular System 

Heart ......................... 50 

Adrenal cortex 

Endocrine System 

......................... 49 

Islets, pancreatic 

Pheochromocytoma benign 

Adrenal medulla 

Capsule, adenoma 

Adenoma 

Thyroid gland 

Pituitary gland 

Parathyroid gland 

Adenoma 

Follicular cell, adenoma 

X 

......................... 48 

X 1 

1 

1 

......................... 50 

++++M++++++++++++++++++++ 48 

++++++++M+MMM++++MM++++M+ 39 

1 

......................... 50 

X 1 

X 

X 

General Body System 

None 

Genital System 

Testes 

Seminal vesicle 

Prostate 

Preputial gland 

Epididymis ......................... 50 

......................... 50 

......................... 50 

......................... 50 

......................... 50 
158 Methylphenidate Hydrochloride, NTP TR 439 

TABLE C2 

(continued) 

Individual Animal Tumor Pathology of Male Mice in the 2-Year Feed Study of Methylphenidate Hydrochloride: 0 ppm 

5666677777777777777777777 

Number of Days on Study 

7790911111111111111111111 

3134744444444444444444444 

6077012359457890123457923 

1606100000111112222222233 

0000000000000000000000000 

Carcass ID Number 

Hematopoietic System 

Spleen 

Lymph node, mesenteric 

Lymph node, mandibular 

Lymph node 

Bone marrow 

Blood 

Hemangiosarcoma 

+++++++++++++++++ ......................... 

......................... 

+++M+++++++++++++++++++++ 

+M+++++++++++++++++++++++ 

++ + 

Thymus ++MM++++++I++++++M+++++++ 

Skin 

Mammary gland 

Integumentary System 

......................... 

MMMMMMMMMMMMMMMMMMMMMMMMM 

Sarcoma X 

Musculoskeletal System 

Bone ......................... 

Nervous System 

Brain ......................... 

Respiratory System 

Lung 

xx 

......................... 

Hepatocellular carcinoma, metastatic, 

Carcinoma, metastatic, harderian 

Alveolarbronchiolar carcinoma 

Alveolarbronchiolar adenoma, 

Alveolarbronchiolar adenoma X X X xx 

multiple X 

gland 

Trachea 

Nose 

liver 

......................... 

......................... 

Special Senses System 

Carcinoma 

Adenoma 

Harderian gland 

X 

+ 

Urinary bladder 

Kidney 

Urinary System 

A++A+++++++++++++++++++++ 

......................... 

Systemic Lesions 

Multiple organs ......................... Lymphoma malignant mixed X X 
Lesions in Male Mice 159 

(continued) 

Individual Animal Tumor Pathology of Male Mice in the 2-Year Feed Study of Methylphenidate Hydrochloride: 0 ppm 

TABLE C2 

1111111171111111111111111 

Number oP Days on Study 

1111111111111111111111111 

4444444444444444444444444 

Carcass ID Number 

0000000000000000000000000 Total 

3334444444455555556666666 TissUesl 

6890234578913457891234689 Tumors 

Hematopoietic System 

Spleen 

Lymph node, mesenteric 

Lymph node, mandibular 

Lymph node 

Bone marrow 

Blood 

Thymus 

Hemangiosarcoma 

+++++M+M++MM++M+M++M++M++ 38 

1 

......................... 50 

+++++M+++++++++++++++++++ 48 

......................... 49 

3 

......................... 50 

11 

X 

~~ ~ ~ ~ ~~~ ~ ~~~ ~ 

Skin 

Mammary gland 

Integumentary System 

~~~ 

2 

......................... 50 

MMMMMMMMMMMMMMMMMMMMMMMMM 

Sarcoma X 

Musculoskeletal System 

Bone ......................... 50 

Nervous System 

Brain ......................... 50 

Respiratory System 

Lung 

1 

X 13 

......................... 50 

4 

1 

4 

......................... 50 

......................... 50 

Hepatocellular carcinoma, metastatic, 

Carcinoma, metastatic, harderian 

Alvmlar/bmnchiolar carcinoma 

Alveolarbronchiolar adenoma, 

Alveolarbmnchiolar adenoma xx X x .x 

multiple 

X xx X 

gland 

Trachea 

NOS? 

liver 

X 

X X X X 

Special Senses System 

Carcinoma 

Adenoma 

Harderian gland 

X 

+ ++ + 

X X 

1 

4 

5 

X 

Urinary bladder 

Kidney 

Urinary System 

......................... 50 

......................... 48 

Systemic Lesions 

Multiple organs 

Lymphoma malignant mixed 3 

......................... 50 

X 
160 Methylphenidate Hydrochloride, NTP TR 439 

Individual Animal Tumor Pathology of Male Mice in the 2-Year Feed Study of Methylphenidate Hydrochloride: 50 ppm 

TABLE C2 

8478000000000000000000000 

2700244444444444444444444 

6677777777777777777777777 

Number of Days on Study 

Carcass ID Number 

6195823482345789045123564 

7871277778888888999000001 

0001100000000000000111111 

Intestine small, ileum 

Intestine small, jejunum 

Intestine small, duodenum 

Intestine large, cecum 

Intestine large, rectum 

Intestine large, colon 

Gallbladder 

Esophagus 

Alimentary System 

Liver 

Sarcoma 

Sarcoma 

Histiocytic sarcoma 

Hepatocellular adenoma, multiple 

Hepatocellular adenoma 

Hepatocellular carcinoma, multiple 

Hepatocellular carcinoma 

Hepatoblastoma 

Hemangiosarcoma 

Sarcoma 

Pancreas 

Sarcoma 

Mesentery 

Stomach, glandular 

Stomach, forestomach 

Salivary glands 

Sarcoma 

Squamous cell papilloma 

A+A++++++++++++++++++++++ 

......................... 

A+A++++++++++++++++++++++ 

A++++++++++++++++++++++++ 

A++++++++++++++++++++++++ 

A++++++++++++++++++++++++ 

A+M+++++++++++++++++M++++ 

......................... 

......................... X X 

X X X X 

X 

X xx 

xx X X 

X 

t 

A++++++++++++++++++++++++ 

......................... 

......................... 

A++++++++++++++++++++++++ 

Cardiovascular System 

Heart ......................... 

Hemangiosarcoma 

Adenocarcinoma, metastatic, prostate X 

X 

Islets, pancreatic 

Adrenal medulla 

Adrenal cortex 

Endocrine System 

Capsule, adenoma 

A++++++++++++++++++++++++ 

A+++M++++++++++++++++++++ 

A++++M+++++++++++++++++++ 

Thyroid gland 

Pituitary gland 

Parathyroid gland 

Adenoma 

......................... 

M+++++++++++++++M++++++++ 

MM++M++M++M+++++++M++++++ 

Follicular cell, adenoma X 

General Body System 

None 
Lesions in Male Mice 161 

(continued) 

Individual Animal Tumor Pathology of Male Mice in the 2-Year Feed Study of Methylphenidate Hydrochloride: 50 ppm 

TABLE C2 

0011111111111111111111111 

4444444444444444444444444 

1111111111111111111111111 

1111111111111111111111111 Total 

1100011112222233333333334 Tissues/ 

6818901231234501234561890 Tumors 

Number of Days on Study 

Carcass ID Number 

Intestine small, ileum 

Intestine small, jejunum 

Intestine small, duodenum 

Intestine large, cecum 

Intestine large, rectum 

Intestine large, colon 

Gallbladder 

Esophagus 

Alimentary System 

Liver 

Sarcoma 

Sarcoma 

Histiocytic sarcoma 

Hepatocellular adenoma, multiple 

Hepatocellular adenoma 

Hepatocellular carcinoma, multiple 

Hepatocellular carcinoma 

Hepatoblastoma 

Hemangiosarcoma 

Sarcoma 

Pancreas 

Sarcoma 

Mesentery 

Stomach, glandular 

Stomach, forestomach 

Salivary glands 

Sarcoma 

Squamous cell papilloma 

.......................... 50 

......................... 41 

......................... 49 

......................... 49 

......................... 49 

.......................... 48 

......................... 48 

......................... 48 

xx X 10 

8 

1 

8 

X 1 

2 

......................... 50 

X 1 

xx xx 

xx 

X xxxx 

X 1 

X 

1 

3 

1 

1 

......................... 49 

1 

......................... 50 

......................... 50 

1 

........................... 49 

X 

++ 

X 

X 

X 

Cardiovascular System 

Heart 

1 

1 

......................... 50 

Hemangiosarcoma 

Adenocarcinoma, metastatic, prostate 

Islets, pancreatic 

Adrenal medulla 

Adrenal cortex 

Endocrine System 

Thyroid gland 

Pituitary gland 

Parathyroid gland 

Adenoma 

1 

......................... 50 

......................... 48 

M+++++++++++MM+M+++++++MM 38 

1 

......................... 48 

......................... 48 

2 

......................... 49 

Capsule, adenoma X X 

X 

Follicular cell, adenoma 

General Body System 

None 
162 Methylphenidate Hydrochloride, NTP TR 439 

(continued) 

Individual Animal Tumor Pathology of Male Mice in the 2-Year Feed Study of Methylphenidate Hydrochloride: 50 ppm 

TABLE C2 

Number of Days on Study 

8478000000000000000000000 

2700244444444444444444444 

6677777777777777777777777 

Carcass ID Number 

6195823482345789045123564 

7871277778888888999000001 

0001100000000000000111111 

Genital System 

Prostate 

Preputial gland 

Epididymis 

Sarcoma 

Sarcoma 

Adenocarcinoma 

Testes 

Seminal vesicle 

X 

......................... 

......................... 

......................... 

A++++++++++++++++++++++++ 

......................... 

Histiocytic sarcoma 

Hemangiosarcoma 

Hematopoietic System 

Pancreatic, sarcoma 

Mediastinal, sarcoma 

Mediastinal, histiocytic sarcoma 

Lymph node, mandibular 

Sarcoma 

Histiocytic sarcoma 

Lymph node, mesenteric 

Sarcoma 

Sarcoma 

Histiocytic sarcoma 

. Bone marrow 

Lymph node 

Spleen 

Thymus 

......................... X 

+ 

X 

+ A 

A+++++M++++++++++++++++++ 

++++M+++++++I++M+++++++++ 

X 

A++++++++++++++++++++++++ 

X 

AM++M++++++++++++++++++++ 

~ 

Skin 

Mammaly gland 

Integumentary System 

......................... 

MMMM+MMMMMMMMMMMMMMMMMMMM 

Musculoskeletal System 

Bone ......................... 

Nervous system 

Brain ......................... 

Respiratory System 

Lung 

Sarcoma, metastatic, mesentery 

Sarcoma 

Histiocytic sarcoma 

Alveolarbronchiolar carcinoma 

Alveolarbronchiolar adenoma 

Adenocarcinoma, metastatic, prostate X 

......................... 

X 

X 

X X X 

X 

X 

Trachea 

Nose 

......................... 

......................... 
Lesions in Male Mice 163 

(continued) 

Individual Animal Tumor Pathology of Male Mice in the 2-Year Feed Study of Methylphenidate Hydrochloride: 50 ppm 

TABLE C2 

0011111111111111111111111 

4444444444444444444444444 

7777777777777777777777777 

Number of Days on Study 

Carcass ID Number 

1111111111111111111111111 Total 

1100011112222233333333334 Tissues/ 

6878901231234501234567890 Tumors 

Genital System 

Prostate 

Preputial gland 

Epididymis 

Sarcoma 

Sarcoma 

Adenocarcinoma 

Testes 

Seminal vesicle 

......................... 50 

......................... 50 

......................... 50 

......................... 50 

2 

......................... 49 

1 

1 

xx 

X 

Histiocytic sarcoma 

Hemangiosarcoma 

Hematopoietic System 

Bone maw 

1 

1 

......................... 50 

Lymph node + ++ -5 

Pancreatic, sarcoma 

Mediastinal, Sarcoma 

Mediastinal, histiocytic sarcoma 

Lymph node, mandibular 

Sarcoma 

Histiocytic sarcoma 

Lymph node, mesenteric 

X 

xx 

......................... 

......................... 

xx 

Spleen ......................... 49 

2 

1 

48 

47 

1 

2 

1 

Sarcoma 

Sarcoma 

Histiocytic sarcoma 

Thymus 

1 

+++MM+M+++++++++M+++M++M+ 41 

1 

1 

X 

X 

Skin 

Mammary gland 

Integumentary System 

MMMMMMMMMMMMMMMMMMMMMMMMM 1 

......................... 50 

Musculoskeletal System 

Bone ......................... 50 

Nervous System 

Brain ......................... 50 

Respiratory System 

Lung ......................... 50 

Sarcoma, metastatic, mesentery 

Sarcoma 

Histiocytic sarcoma 

Alveolarbronchiolar carcinoma 

Alveolarbronchiolar adenoma 

Adenocarcinoma, metastatic, prostate 

Trachea 

Nose 

1 

1 

1 

5 

6 

1 

......................... 50 

......................... 50 

X X 

X X X 

X 

X 
164 Methylphenidate Hydrochloride, NTP TR 439 

(continued) 

Individual Animal Tumor Pathology of Male Mice in the %Year Feed Study of Methylphenidate Hydrochloride: 50 ppm 

TABLE C2 

Number of Days on Study 

8478000000000000000000000 

2700244444444444444444444 

66777777777777777777777.77 

Carcass ID Number 

6195823482345789045123564 

7871277778888888999000001 

0001100000000000000111111 

Harderian gland 

Ear 

Special Senses System 

Adenoma 

+ 

X 

+ 

Urinary bladder 

Kidney 

Urinary System 

~~~ ~~ ~ ~~ ~~ 

......................... 

......................... Histiocytic sarcoma X 

Systemic Lesions 

Multiple organs ......................... 

Lymphoma malignant mixed 

Lymphoma malignant lymphocytic 

Histiocytic sarcoma X 

X X 
Lesions in Male Mice 165 

(continued) 

Individual Animal Tumor Pathology of Male Mice in the 2-Year Feed Study of Methylphenidate Hydrochloride: 50 ppm 

TABLE C2 

0011111111111111111111111 

4444444444444444444444444 

1111171111717111111171711 

1111111111111111111111111 Total 

1100011112222233333333334 Tissues/ 

6818901231234501234561890 Tumors 

Number of Days on Study 

Carcass ID Number 

Harderian gland 

Ear 

Special Senses System 

Adenoma 

+ 

1 

2 

1 

Kidney 

Urinary System 

Histiocytic sarcoma 

Urinary bladder ......................... 48 

1 

......................... 50 

Systemic Lesions 

Multiple organs 

1 

1 

......................... 50 

Lymphoma malignant mixed X 4 

Lymphoma malignant lymphocytic 

Histiocytic sarcoma 

X 

X 
166 Methylphenidate Hydrochloride, NTP TR 439 

Individual Animal Tumor Pathology of Male Mice in the 2-Year Feed Study of Methylphenidate Hydrochloride: 250 ppm 

TABLE C2 

1510601666666777777777700 

5566677777777777777777777 

Number of Days on Study 4801213333333333333333344 

Carcass ID Number 

7519473925689.156791234001 

6500007566.666444445555677 

1122221111111111111111111 

Liver 

Intestine small, ileum 

Intestine small, jejunum 

Intestine small, duodenum 

Intestine large, cecum 

Intestine large, rectum 

Intestine large, colon 

Gallbladder 

Esophagus 

Alimentary System 

Hepatocellular adenoma, multiple 

Hepatocellular adenoma 

Hepatocellular carcinoma, multiple 

Hepatocellular carcinoma 

Hepatoblastoma, multiple 

Hemangiosarcoma 

Hemangioma 

Tongue 

Stomach, glandular 

Stomach, forestomach 

Salivary glands 

Pancreas 

Mesentery 

......................... 

......................... 

......................... 

.......................... 

......................... 

......................... 

++A++A+++++++++++++++++++ 

++AMM++++++++++MMM+++++++ 

++M++++++++++++++++++++++ 

X 

X 

x xxxxxx 

X 

X xx X 

X X 

X 

X 

X X 

X 

X 

......................... 

......................... 

.......................... 

......................... 

+ 

Cardiovascular System 

Heart ......................... 

Adrenal medulla 

Adenoma 

Adrenal cortex 

Endocrine System 

+++++++++++M+++++++++++++ 

......................... X 

Islets, pancreatic 

Pituitary gland 

Parathyroid gland 

Adenoma 

Thyroid gland ++M++++++++++++++++++++++ 

+++++++M+++M++M+M+M++M++.+ 

++MM+MM+MMM++++++++++MM++ 

......................... X 

Pars intermedia, carcinoma X 

General Body System 

None 

Genital System 

Testes 

Seminal vesicle 

Prostate 

Preputial gland 

Penis 

Epididymis 

Interstitial cell, adenoma 

......................... 

......................... 

......................... 

++A++++++++++++++++++++++ 

++++++++++++++++++M++++++ 
Lesions in Male Mice 167 

(continued) 

Individual Animal Tumor Pathology of Male Mice in the 2-Year Feed Study of Methylphenidate Hydrochloride: 250 ppm 

TABLE C2 

0000000000000000000000000 

4444444444444444444444444 

1711111711171117171111711 

1111111111111111111122222 Total 

7111788888888999999900001 TirsUf.31 

5618902345689245618903580 Tumors 

Number of Days on Study 

Carcass ID Number 

Intestine large, colon 

Gallbladder 

Esophagus 

Alimentary System 

......................... 49 

......................... 44 

......................... 48 

Liver 

Intestine small, ileum 

Intestine small, jejunum 

Intestine small, duodenum 

Intestine large, cecum 

Intestine large, rectum 

Hepatocellular adenoma, multiple 

Hepatocellular adenoma 

Hepatocellular carcinoma, multiple 

Hepatocellular carcinoma 

Hepatoblastoma, multiple 

Hemangiosarcoma 

Hemangioma 

Tongue 

Stomach, glandular 

Stomach, forestomach 

Salivary glands 

Pancreas 

Mesentery 

......................... 48 

......................... 48 

......................... 48 

++++++++++++++++++++++++M 47 

......................... 48 

......................... 50 

1 

1 

1 

1 

......................... 50 

......................... 50 

......................... 50 

......................... 50 

1 

6 

X 10 

2 

xx 15 

X 

X X X 

X X X 

X xx X 

+ 

Cardiovascular System ~~ 

Heart ......................... 50 

Adrenal cortex 

Endocrine System 

......................... 50 

Adenoma 

Islets, pancreatic 

Adrenal'medulla 

Pituitary gland 

Parathyroid gland 

Adenoma 

Thyroid gland 

Pars intermedia, carcinoma 

......................... 50 

......................... 49 

1 

......................... 44 

++M+M+++++MM+++++++++M++M 35 

1 

......................... 49 

1 

General Body System 

None 

Genital System 

Testes 

Seminal vesicle 

Prostate 

Preputial gland 

Penis 

Epididymis 

......................... 49 

......................... 49 

1 

......................... 50 

2 

......................... 50 

......................... 

+ 

50 

Interstitial cell, adenoma X X 
168 Methylphenidate Hydrochloride, NTP TR 439 

TABLE C2 

151.0601666666777777777700 

4801213333333333333333344 

5566677777777777777777777 

Number of Days on Study 

1122221111111111111111111 

Carcass ID Number 

7519473925689156791234001 

6500007566666444445555677 

Hemangiosarcoma 

Hematopoietic System 

Bone marrow 

Spleen 

Lymph node, mesenteric 

Lymph node, mandibular 

Lymph node 

Thymus 

......................... X 

.+++++++++++++++++++M+++++ 

++MM+M+++++++++++++M+++++ 

+++M+++++++++++++++++++++ 

Hemangiosarcoma X 

M++M++M++M+M+++++M++M++++ 

Skin 

Mammary gland 

Integumentary System 

......................... 

MMMMMMMMMMMMMMMMMMMMMMMMM 

Lipoma X, 

Musculoskeletal System 

Bone. ......................... 

Nervous System 

Brain ......................... Carcinoma, metastatic, pituitary 

gland X 

Respiratory System 

Lung ......................... 

Hepatocellular carcinoma, metastatic, 

Alveolar/bronchiolar carcinoma 

Alveolar/bronchiolar adenoma, 

Alveolar/bronchiolar adenoma X .x X X 

multiple 

X 

Trachea 

Nose 

liver X X X X 

++M+++M++++++++++++++++++ 

......................... 

Special Senses System 

None 

Urinary Bladder 

Kidney 

Urinary System 

++A++A+++++++++++++++++++ 

......................... 

Systemic Lesions 

Multiple organs 

Lymphoma malignant mixed 

......................... X 
Lesions in Male Mice 169 

TABLE C2 

(continued) 

Individual Animal Tumor Pathology of Male Mice in the 2-Year Feed Study of Methylphenidate Hydrochloride: 250 ppm 

0000000000000000000000000 

4444444444444444444444444 

1171111171111117117771177 

1111111111111111111122222 Total 

1711788888888999999900001 Tissues/ 

5618902345689245618903580 Tumors 

Number of Days on Study 

Carcass ID Number 

Hemangiosarcoma 

Hematopoietic System 

Lymph node 

Bone marrow 

1 

1 

......................... 50 

+ 

Spleen 

Lymph node, mesenteric 

Lymph node, mandibular 

Thymus 

Hemangiosarcoma 

......................... 49 

+++++++++++M+++++++++++++ 45 

......................... 49 

+M+++++++++++M+M+++M+++M+ 38 

1 

Skin 

Mammary gland 

Integumentary System 

......................... 50 

MMMMMMMMMMMMMMMMMMMMMMMMM 

Lipoma 1 

Musculoskeletal System 

Bone ......................... 50 

Nervous System 

Brain 

1 

......................... 50 

Carcinoma, metastatic, pituitary 

Respiratory System 

gland 

Lung 

2 

X 2 

5 

......................... 50 

......................... 48 

......................... 50 

4 

Hepatocellular carcinoma, metastatic, 

Alveolarbronchiolar carcinoma 

Alveolarbronchiolar adenoma, 

Alveolarbronchiolar adenoma X 

multiple X 

X 

Trachea 

Nose 

liver 

Special Senses System 

None 

Urinary bladder 

Kidney 

Urinary System 

......................... 50 

......................... 48 

Systemic Lesions 

Multiple organs 

Lymphoma malignant mixed 3 

......................... 50 

X X 
170 Methylphenidate Hydrochloride, NTP TR 439 

Number of Days on Study 

4867447070003333333333333 

5666666777771777171777177 

I124588003333333333333333 

2222222222222222222222222 

Carcass ID Number 

1150017392465567891385689 

1417261771111222223335555 

Alimentary System 

Liver 

Intestine small, ileum 

Intestine small, jejunum 

Intestine small, duodenum 

Intestine large, cecum 

Intestine large, rectum 

Intestine large, colon 

Gallbladder 

Esophagus 

Histiocytic sarcoma 

Hepatocellular adenoma, multiple 

Hepatocellular adenoma 

Hepatocellular carcinoma, multiple 

Hepatocellular carcinoma 

Hepatoblastoma, multiple 

Hepatoblastoma 

Mesentery 

......................... 

AA++A+++A++++++++++++++++ 

AA++A+++A++++++++++++++++ 

......................... 

+A++A+++A++++++++++++++++ 

+++++++MA++++++++++++++++ 

+A++A+++A++++++++++++++++ 

AA++A+A+A+++++++++M++++++ 

......................... 

X xx 

X 

xxx X 

X 

xxx X xx x X 

.x xx X 

X 

Hemangiosarcoma, metastatic, spleen 

Hepatoblastoma, metastatic, liver 

Salivary glands 

Pancreas 

......................... 

......................... X 

Tongue 

Stomach, glandular 

Stomach, forestomach 

+ 

AA++A++++++++++++++++++++ 

......................... 

+ 

Cardiovascular System 

Heart ......................... 

Endocrine System 

Islets, pancreatic 

Adrenal medulla 

Adrenal &rtex 

Pituitary gland 

Parathyroid gland 

Adenoma 

Thyroid gland 

Pars intermedia, adenoma 

.......................... 

++++++++M++++++++++++++++ 

.......................... 

A 

+M+++++M++++.++++++++++M++ 

IM++++++++++++M++++++++++ 

X ......................... 

General Body System 

None 

Genital System 

Testes 

Seminal vesicle 

Prostate 

Preputial gland 

Epididymis 

......................... 

......................... 

+++++++++++++++++++++M+++ 

++++++++M++++++++++++++++ 

......................... 
Lesions in Male Mice 171 

(continued) 

Individual Animal Tumor Pathology of Male Mice in the 2-Year Feed Study of Methylphenidate Hydrochloride: 500 ppm 

TABLE C2 

Number of Days on Study 

3333333444444555566666666 

3333333333333333333333333 

1111111111111111111111111 

Carcass ID Number 

2222222222222222222222222 Total 

6666118361117444512234446 Tissues/ 

0468480591261239283490572 Tumors 

Liver 

Intestine small, ileum 

Intestine small, jejunum 

Intestine small, duodenum 

Intestine large, cecum 

Intestine large, rectum 

Intestine large, colon 

Gallbladder 

Esophagus 

Alimentary System 

Histiocytic sarcoma 

Hepatocellular adenoma, multiple 

Hepatocellular adenoma 

Hepatocellular carcinoma, multiple 

Hepatocellular carcinoma 

Hepatoblastoma, multiple 

Hepatoblastoma 

Hemangiosarcoma, metastatic, spleen 

Hepatoblastoma, metastatic, liver 

Salivary glands 

Pancreas 

Mesentery 

Tongue 

Stomach, glandular 

Stomach, forestomach 

......................... 

......................... 

......................... 

......................... 

......................... 

......................... 

......................... 

......................... 

......................... 

X xx X 

X xx 

xxx X xx X 

X xx xx xxx X X 

X 

++ 

......................... 

.......................... 

......................... 

......................... 

2 

41 

50 

50 

1 

50 

1 

2 

1 

14 

15 

1 

10 

1 

4 

50 

46 

46 

48 

41 

48 

41 

44 

50 

Cardiovascular System 

~~~~ 

Heart ......................... 50 

Islets, pancreatic 

Adrenal medulla 

Adrenal cortex 

Endocrine System 

Pituitary gland 

Parathyroid gland 

Adenoma 

General Body System 

Thyroid gland 

......................... 50 

M++++++++++++++++++++++++ 48 

......................... 50 

++++++++++++++M+MM+++++++ 44 

M+++++++M+M+M+MMM++M+MM++ 31 

1 

......................... 50 

Pars intermedia, adenoma 1 

None 

Genital System 

Testes 

Seminal vesicle 

Prostate 

Preputial gland 

Epididymis ......................... 50 

......................... 49 

++++++++++++++++M++++++++ 48 

......................... 50 

......................... 50 
172 Methylphenidate Hydrochloride, NTP TR 439 

(continued) 

Individual Animal Tumor Pathology of Male Mice in the 2-Year Feed Study of Methylphenidate Hydrochloride: 500 ppm 

TABLE C2 

4867447070003333333333333 

7124588003333333333333333 

5666666777777777777777777 

Number of Days on Study 

2222222222222222222,222222 

Carcass ID Number 

1150017392465567891385689 

1477261771111222223335555 

Hematopoietic System 

Bone marrow 

Blood ++++ ......................... Hemangiosarcoma 

Spleen 

Lymph node, mesenteric 

Lymph node, mandibular 

Lymph node 

Mast cell tumor NOS 

X 

X 

+ + 

......................... 

+++++M++A++++++++++++++++ 

'++++++++A++++++++++++++++ 

Mast cell tumor NOS 

Hemangiosarcoma X X 

X 

Thymus ++"++"MI +++I +M+MM++++++ 

Skin 

Mammary gland 

Integumentary System 

Hemangiosarcoma 

Fibroma 

......................... 

MMM+MMMMMMMMMMMMMMMMMMMMM 

X 

Musculoskeletal System 

Bone ......................... 

Nervous System 

Spinal cord 

Peripheral nerve 

Brain ......................... 

+ 

+ 

Respiratory System 

Lung 

Carcinoma, metastatic, harderian 

Alveolarbronchiolar carcinoma 

Alveolarbronchiolar adenoma 

Histiocytic sarcoma 

Hepatoblastoma, metastatic, liver 

gland 

Trachea 

Nose 

......................... X X 

X 

X 

X 

X 

......................... 

......................... 

Special Senses System 

Carcinoma 

Adenoma 

Harderian gland 

X 

+ 

Urinary bladder 

Kidney 

Urinary System 

AA++++++A++++++++++++++++ 

......................... 
Lesions in Male Mice 173 

(continued) 

Individual Animal Tumor Pathology of Male Mice in the 2-Year Feed Study of Methylphenidate Hydrochloride: 500 ppm 

TABLE C2 

3333333444444555566666666 

3333333333333333333333333 

7777777777777777777777777 

Number of Days on Study 

Carcass ID Number 

2222222222222222222222222 Total 

6666778367777444512234446 Tissues/ 

0468480591267239283490572 Tumors 

Hematopoietic System 

Bone marrow 

Blood 

Hemangiosarcoma 

Spleen 

Lymph node, mesenteric 

Lymph node, mandibular 

Lymph node 

Mast cell tumor NOS 

Mast cell tumor NOS 

Hemangiosarcoma 

Thymus 

+++ 

X 2 

......................... 49 

7 

1 

......................... 49 

++++++++++++++++M++++++++ 47 

......................... 50 

X 3 

1 

........................ 38 

Skin 

Mammary gland 

Integumentary System 

Hemangiosarcoma 

Fibroma 

1 

1 

50 

MMMM+MMMMMMMMMMMMMMMMMMMM 2 

......................... X 

Musculoskeletal System 

Bone 

~~_____ ~~~~~ ~ ~ ~~ ~~ 

......................... 50 

Nervous System 

Spinal cord 

Peripheral nerve 

Brain 

1 

1 

......................... 50 

Respiratory System 

Lung 

1 

X 5 

......................... 50 

1 

1 

1 

......................... 50 

......................... 50 

Carcinoma, metastatic, harderian 

Alveolar/bronchiolar carcinoma 

Alveolarbronchiolar adenoma 

Histiocytic sarcoma 

Hepatoblastoma, metastatic, liver 

X X 

gland 

Trachea 

Nose 

Special Senses System 

Carcinoma 

Adenoma 

Harderian gland 

X 

+ 

1 

1 

2 

Urinary bladder 

Kidney 

Urinary System 

......................... 50 

......................... 47 
174 Methylphenidate Hydrochloride, NTP TR 439 

(continued) 

Individual Animal Tumor Pathology of Male Mice in the 2-Year Feed Study of Methylphenidate Hydrochloride: 500 ppm 

TABLE C2 

4867447070003333333333333 

7124588003333333333333333 

5666666777777777777777777 

1150017392465567891385689 

1477261771111222223335555 

2222222222222222222222222 

Number of Days on Study 

Carcass ID Number 

Systemic Lesions 

Multiple organs ......................... 

Lymphoma malignant mixed 

Lymphoma malignant lymphocytic 

Histiocytic sarcoma X 

X 

X X xx X 
Lesions in Male Mice 175 

(continued) 

Individual Animal Tumor Pathology of Male Mice in the 2-Year Feed Study of Methylphenidate Hydrochloride: 500 ppm 

TABLE C2 

3333333444444555566666666 

3333333333333333333333333 

1117111111111111111111111 

2222222222222222222222222 Total 

6666718367111444512234446 Tissues/ 

0468480591261239283490512 Tumors 

Number of Days on Study 

Carcass ID Number 

~~ 

Systemic Lesions 

~~~~~~~ ~~~ 

Multiple organs 

8 

1 

1 

......................... 50 

Lymphoma malignant mixed 

Lymphoma malignant lymphocytic 

Histiocytic sarcoma 

X xx 

I 
176 Methylphenidate Hydrochloride, NTP TR 439 

Statistical Analysis of Primary Neoplasms in Male Mice in the 2-Year Feed Study of Methylphenidate Hydrochloride 

TABLE C3 

0 PPm 50 PPm 250 ppm 500 ppm 

Fisher exact test 

Cochran-Armita e testd 

Logistic regression testsd 

Life table tests 

First incidence days 

Terminal rates' 

Adjusted ratesb 

Overall ratesa 

Harderian Gland: Adenoma 

Fisher exact test 

Cochran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

Harderian Gland: Adenoma or Carcinoma 

Fisher exact test 

Cochran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

Liver: Hemangiosarcoma 

Fisher exact test 

Cochran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

Liver: Hepatocellular Adenoma 

Fisher exact test 

Cochran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

Liver: Hepatocellular Carcinoma 

i 

J) 

8.9% 

4/50 (8%) 

P=0.134N 

P=O.l52N 

P=0.152N 

73O'(T) 

4/45 (9%) 

730 (9 

5/45 (11%) 

5/50 (10%) 

11.1% 

P=0.218N 

P=0.247N 

P=0.247N 

6.7% 

3/50 (6%) 

730 (9 

3/45 (7%) 

P=O.O63N 

P=0.073N 

P=0.073N 

P=O.O12 

P=O.O09 

P=O.O04 

679 

17/45 (38%) 

39.1% 

18/50 (36%) 

P=O.284 

P=O.396 

P=O.224 

537 

7/45 (16%) 

20.7% 

10/50 (20%) 

1/50 (2%) 

P=0.181N 

P=0.180N 

P=0.180N 

1/45 (2%) 

2.2% 

730 (T) 

1/50 (2%) 

P=O.l02N 

P=0.104N 

P=0.104N 

1/45 (2%) 

2.2% 

730 (9 

2/45 (4%) 

4.4% 

2/50 (4%) 

P=0.500N 

P=0.5O0N 

P=0.500N 

730 (9 

P=0.524N 

P=0.579N 

720 

17/45 (38%) 

39.1% 

18/50 (36%) 

P=O.582N 

P=0.598N 

P=0.494N 

707 

8/45 (18%) 

19.5% 

9/50 (18%) 

P=0.500N 

0/50 (0%) 

P=O.O59N 

P=0.066N 

P=0.066N 

e 

0/44 (0%) 

0.0% 

- 

0/50 (0%) 

P=0.028N 

P=0.036N 

P=0.036N 

0/44 (0%) 

0.0% 

- 

1/50 (2%) 

P=0.309N 

P=0.314N 

P=0.314N 

1/44 (2%) 

2.3% 

730 (9 

P=0.437N 

P=0.449N 

610 

15/44 (34%) 

35.5% 

16/50 (32%) 

P=0.417N 

P=O.101 

P=O.o95 

541 

12/44 (27%) 

34.7% 

17/50 (34%) 

P=O.O88 

P=0.209N 

P=0.209N 

730 (T) 

1/41 (2%) 

2.4% 

1/50 (2%) 

P=0.181N 

730 (T) 

2/41 (5%) 

4.9% 

2/50 (4%) 

P=0.256N 

P=0.256N 

P=0.218N 

0/50 (0%) 

P=0.138N 

P=0.138N 

0/41 (0%) 

0.0% 

- 

P=0.121N 

P=O.O20 

P=O.OlO 

618 

25/41 (61%) 

64.2% 

29/50 (58%) 

P=O.O22 

P=O.564 

P=O.442 . 

574 

6/41 (15%) 

23.4% 

11/50 (22%) 

P=O.500 
Lesions in Male Mice 177 

(continued) 

Statistical Analysis of Primary Neoplasms in Male Mice in the 2-Year Feed Study ofMethylphenidate Hydrochloride 

TABLE C3 

250 ppm 500 ppm 

Fisher exact test 

Cochran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

Liver: Hepatocellular Adenoma or Carcinoma 

P=O.O12 

P=O.O16 P=0.505N 

P=O.O06 P=0.494N 

537 707 

21/45 (47%) 21/45 (47%) 

49.9% 48.9% 

24/50 (8%) 23/50 (46%) 

P=0.500N 

P=O.444 

P=O.389 

541 

21/44 (48%) 

53.0% 

26/50 (52%) 

P=O.O37 

P=O.O22 

574 

27/41 (66%) 

70.7% 

34/50 (68%) 

P=O.421 P=O.O34 

Fisher exact test 

Cochran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

Liver: Hepatoblastoma 

0/50 (0%) 1/50 (2%) 

0.0% 2.2% 

0/45 (0%) 1/45 (2%) 

P=O.O06 

P=O.O04 P=O.500 

P=O.O04 P=O.500 

- 730 (T> 

P=O.500 

P=O.496 

P=O.496 

730 0 

1/44 (2%) 

2.3% 

1/50 (2%) 

5/41 (12%) 

12.2% 

5/50 (10%) 

P=O.O26 

P=O.O26 

730 (T) 

P=O.500 P=O.O28 

Fisher exact test 

Cochran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

Liver: Hepatocellular Carcinoma or Hepatoblastoma 

P=O.o68 

P=O.O67 

541 

13/44 (30%) 

36.7% 

18/50 (36%) 

P=O.274 

P=O.206 

574 

9/41 (22%) 

30.0% 

14/50 (28%) 

P=O.114 

P=O.171 P=O.509 

P =0.084 P=0.589N 

537 707 

7/45 (16%) 

20.7% 21.7% 

10/50 (20%) 10/50 (20%) 

9/45 (20%) 

P=0.598N P=O.O59 P=O.241 

Fisher exact test 

Cochran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

Liver: Hepatocellular Adenoma, Hepatocellular Carcinoma, or Hepatoblastoma 

P=O.O12 

P=O.O16 P=0.505N 

P=O.O06 P=0.494N 

537 707 

21/45 (47%) 21/45 (47%) 

49.9% 48.9% 

24/50 (8%) 23/50 (46%) 

P=0.500N 

P=O.444 

P=O.389 

541 

21/44 (48%) 

53.0% 

26/50 (52%) 

P=O.O37 

P=O.O22 

574 

27/41 (66%) 

70.7% 

34/50 (68%) 

P=O.421 P=O.O34 

Fisher exact test 

Cochran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

Lung: Alveolarlbronchiolar Adenoma 

P=0.045N 

P=0.046N P=0.053N 

P=0.068N P=0.042N 

537 

12/45 (7%) 6/45 (13%) 

29.6% 13.3% 

14/50 (28%) 6/50 (12%) 

730 (T) 

P=0.039N 

7/44 (16%) 

15.9% 

7/50 (14%) 

P=O.o68N 

P=O.O82N 

730 (T) 

5/41 (12%) 

12.2% 

5/50 (10%) 

P=0.020N 

P=0.035N 

730 0 

P=0.070N P=0.020N 
17% Methylphenidate Hydrochloride, NTP TR 439 

TABLE C3 

(continued) 

Statistical Analysis of Primary Neoplasms in Male Mice in the 2-Year Feed Study of Methylphenidate Hydrochloride 

Fisher exact test 

Gxhran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

Lung: Alveolarbronchiolar Carcinoma 

Fisher exact test 

Gxhran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

Lung: Alveolar/bronchiolar Adenoma or Carcinoma 

Fisher exact test 

Cochran-Annitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

Spleen: Hemangiosarcoma 

Fisher exact test 

Cochran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

All Organs: Hemangiosarcoma 

Fisher exact test 

Cochran-Annitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

All Organs: Hemangioma or Hemangiosarcoma 

8.9% 

4/50 (8%) 

P=0.061N 

P=0.067N 

P=0.075N 

730 0 

4/45 (9%) 

P=0.019N 

P=0.021N 

P=0.033N 

537 

14/45 (31%) 

33.9% 

16/50 (32%) 

1/45 (2%) 

2.2% 

1/50 (2%) 

P=O.O77 

P=O.O75 

P=O.o65 

730 0 

8.9% 

4/50 (8%) 

730 0 

4/45 (9%) 

P=0.391N 

P=0.413N 

P=0.436N 

8.9% 

4/50 (8%) 

730 (T> 

4/45 (9%) 

P=0.425N 

P=0.450N 

P=O.473N 

730 (?? 

5/45 (11%) 

5/50 (10%) 

11.1% 

P =os00 

P=O.500 

P=O.500 

10/50 (20%) 

P=O.lUN 

P=O.l48N 

P=O.l3ON 

10/45 (22%) 

22.2% 

730 (T) 

0145 (0%) 

0.0% 

0/49 (0%) 

P=0.500N 

P=0.500N 

- 

P=0.505N 

6.7% 

3/50 (6%) 

P=0.500N 

P=0.500N 

730 (T) 

3/45 (7%) 

P=O.5OON 

6.7% 

3/50 (6%) 

730 (T) 

3/45 (7%) 

P=0.500N 

P=0.500N 

P=O.S00N 

' J. 

730 0 

a44 (5%) 

2/50 (4%) 

4.5% 

P=0.339N 

P=0.348N 

P=O.348N 

20.5% 

9/50 (18%) 

730 (?? 

9/44 (20%) 

P=O.O83N 

P=O.O83N 

P=O.O97N 

1/43 (2%) 

2.3% 

1/49 (2%) 

P=O.751 

P=O.751 

730 0 

P=O.747 

1/50 (2%) 

P=0.181N 

P=O.l87N 

P=0.187N 

1/44 (2%) 

2.3% 

730 0 

730 0 

2/44 (5%) 

4.5% 

2/50 (4%) 

P=O.339N 

P=0.348N 

P=O.348N 

P=0.181N 

P=O.U)5N 

684 

0/41 (0%) 

2.2% 

1/50 (2%) 

P=0.181N 

P=O.O14N 

P=0.028N 

684 

5/41 (12%) 

14.1% 

6/50 (1 2%) 

P=0.014N 

7.0% 

3/50 (6%) 

P=O.304 

P=O.283 

684 

P=O.309 

2l41 (5%) 

P=OSlON 

P=0.543N 

684 

2/41 (5%) 

7.0% 

3/50 (6%) 

P=OSOON 

P=0.510N 

P=O.543N 

684 

2/41 (5%) 

7.0% 

3/50 (6%) 

P-OSOON 
Lesions in Male Mice 179 

(continued) 

Statistical Analysis of Primary Neoplasms in Male Mice in the 2-Year Feed Study of Methylphenidate Hydrochloride 

TABLE C3 

50 PPm 250 ppm 

Fisher exact test 

Cochran-Annitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

All Organs: Malignant Lymphoma (Lymphocytic or Mixed) 

6.4% 

3/50 (6%) 

P=O.O50 

P=O.O56 

P=O.O38 

617 

2/45 (4%) 

10.8% 

5/50 (10%) 

P=O.307 

P=O.363 

708 

4/45 (9%) 

6.6% 

3/50 (6%) 

P=0.639N 

P=O.645 

626 

2/44 (5%) 

P=O.O64 

P=O.O52 

654 

7/41 (17%) 

20.7% 

9/50 (18%) 

P=O.357 P=0.661N P=O.o61 

Fisher exact test 

Cochran-Annitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

All Organs: Benign Neoplasms 

P=O.179 

P=O.150 

P=O.O75 

537 

28/45 (62%) 

64.5% 

31/50 (62%) 

P=0.074N 

P=0.086N 

720 

22/45 (49%) 

50.0% 

23/50 (46%) 

P=0.086N 

P=0.106N 

610 

22/44 (50%) 

51.1% 

23/50 (46%) 

P=O.411 

P=O.239 

618 

29/41 (71%) 

73.1 % 

33/50 (66%) 

P=0.080N P=0.080N P=O.418 

Fisher exact test 

Cochran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

All Organs: Malignant Neoplasms 

P=O.158 

P=O.244 

628 

20/45 (44%) 

48.9% 

24/50 (48%) 

P=O.383 

P=O.329 

541 

16/44 (36%) 

44.0% 

22/50 (44%) 

P=O.274 

P=O.166 

574 

17/41 (41%) 

49.8% 

24/50 (48%) 

P=O.288 

P=O.453 

P=O.198 

537 

14/45 (31%) 

38.0% 

19/50 (38%) 

P=O.210 P=O.342 P=O.210 

Fisher exact test 

Cochran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

All Organs: Benign or Malignant Neoplasms 

P=O.206 

P=O.282 

P=O.O94 

537 

36/45 (80%) 

82.0% 

41/50 (82%) 

P=0.118N 

P=0.163N 

628 

30/45 (67%) 

70.0% 

35/50 (70%) 

P=0.045N 

P=0.129N 

541 

27/44 (61%) 

66.0% 

33/50 (66%) 

P=O.434 

P=O.195 

574 

35/41 (85%) 

87.7% 

43/50 (86%) 

P=0.121N P=0.055N P=O.393 

a Number of neoplasm-bearing animals/number of animals examined. Denominator is number of animals examined microscopically for liver, lung, 

(T)Terminal sacrifice 

exact tests compare directly the overall incidence rates. For all tests, a negative trend or a lower incidence in an exposure group is indicated by N. 

as being (directly or indirectly) the cause of death. The logistic regression test regards these lesions as nonfatal. The Cochran-Armitage and Fisher 

to paitwise comparisons between the controls and that exposed group. The life table test regards neoplasms in animals dying prior to terminal kill 

Beneath the control incidence are the P values associated with the trend test. Beneath the exposed group incidence are the P values corresponding 

Observed incidence at terminal kill 

Kaplan-Meier estimated neoplasm incidence at the end of the study after adjustment for intercurrent mortality 

and spleen; for other tissues, denominator is number of animals necropsied. 

e Not applicable; no neoplasms in animal group 
180 Methylphenidate Hydrochloride, NTP TR 439 

Historical Incidence of Liver Neoplasms in Untreated Male B6C3F, Micea 

TABLE C4 

Study 

Incidence in Controls 

Adenoma 

Hepatocellular Hepatocellular 

or Hepatoblastoma 

Hepatocellular Adenoma, 

Carcinoma . Hepatoblastoma Hepatocellular Carcinoma, 

Historical Incidence at TSI Mason Research Institute 

Turmeric oleoresin 

Pentaerythritol tetranitrate 

HC Yellow 4 

Acetaminophen 

l-Amino-2,4-dibrornoanthraquinone 

25/50 

9/48 

8/49 

11/50 

10/50 

12/50 

3/48 

5/49 

1/50 

9/50 

0/50 

0148 

0/49 

0/50 

O/SO 

30/50 

11/48 

13/49 

16/50 

18/50 

Overall Historical Incidence 

Range 

Standard deviation 

Total 312/1,366 (22.8%) 223/1,366 (16.3%) 0/1,366 

14.3% 

485/1,366 (35.5%) 

13.8% 7.2% 

4%-60% 3%-29% 10%-68% 

a Data as of 20 August 1992 
Lesions in Male Mice 181 

of Methylphenidate Hydrochloride' 

Summary of the Incidence of Nonneoplastic Lesions in Male Mice in the 2-Year Feed Study 

TABLE C5 

0 PPm 50 PPm 250 ppm 500 ppm 

Early deaths 

IS-MO?Uh inraim ntolkrrhopl 

PMO?UhinraimC?VdUfh 

Animals initially in study 

Disposition Summary 

Terminal sacrifice 

Died last week of study 

Natural deaths 

Moribund 

Survivors 

10 

10 

70 

3 

2 

45 

10 

10 

70 

3 

2 

45 

10 

10 

70 

2 

4 

43 

1 

10 

10 

70 

5 

4 

41 

Animals examined microscopically 70 70 70 70 

9-Month Interim Evaluation 

Alimentary System 

Stomach, glandular 

Salivary glands 

Mesentery 

Liver 

Perivascular, inflammation, chronic 

Inflammation, chronic, focal 

Fat, necrosis 

Fatty change 

None 

Cardiovascular System 

Endocrine System 

Hyperplasia 

Islets, pancreatic 

Atrophy 

Adrenal cortex 

None 

General Body System 

Abscess 

Preputial gland 

Genital System 

Cyst 

Prostate 

Inflammation, chronic, focal 

1 (100%) 

(9) 

~~~~ ~~ ~~ 

a Number of animals examined microscopically at site and number of animals with lesion 
182 Methylphenidate Hydrochloride, NTP TR 439 

of Methylphenidate Hydrochloride (continued) 

Summary of the Incidence of Nonneoplastic Lesions in Male Mice in the 2-Year Feed Study 

TABLE C5 

0 PPm 50 PPm 250 PPm 500 ppm 

i 

None 

Hematopoietic System 

9-Month Interim Evaluation (continued) 

None 

Musculoskeletal System 

Brain 

Nervous System 

Mineralization, focal 

Lung 

Respiratory System 

(10) (10) (10) (10) 

Peribronchial, inflammation, chronic 

Congestion 

Metaplasia, squamous 

Inflammation, chronic, focal 

Degeneration, hyaline 

1 (10%) 

4 (40%) 4 (40%) 

3 (30%) 

7 (70%) 3 (30%) 

Nose (10) (10) (10) (10) 

1 (10%) 1 (10%) 1 (10%) 

10 (100%) 10 (100%) 

2 (20%) 

10 (100%) 8 (80%) 

None 

Special Senses System 

Kidney 

Urinary System 

(10) (10) (10) (10) 

Inflammation, chronic, focal 

Calculus micro observation only 

Renal tubule, regeneration 

Inflammation, chronic, focal 1 (10%) 

3 (30%) 3 (30%) 2 (20%) 

1 (10%) 

1 (10%) 

Urinary bladder (10) (10) (10) (10) 

3 (30%) 

15-Month Interim Evaluation 

Alimentary System 

Fatty change 

Eosinophilic focus 

Clear cell focus 

Basophilic focus 

Liver 

Inflammation, chronic 

Inflammation, chronic, focal 

Inflammation, chronic, focal 

Stomach, glandular 

Salivary glands 

Pancreas 

(10) 

1 (10%) 

1 (10%) 

4 (40%) 

(10) 
Lesions in Male Mice 183 

of Methylphenidate Hydrochloride (continued) 

Summary of the Incidence of Nonneoplastic Lesions in Male Mice in the 2-Year Feed Study 

TABLE C5 

0 PPm 50 PPm 250 ppm 500 ppm 

None 

Cardiovascular System 

15-Month Interim Evaluation (continued) 

Hyperplasia 

Islets, pancreatic 

Hyperplasia, focal 

Adrenal coitex 

Endocrine System 

None 

General Body System 

Genital System 

Atrophy 

Abscess 

Preputial gland 

Inflammation, chronic 

Inflarpmation, acute 

Inflammation, chronic 

Dilatation 

Cyst 

Prostate 

3 (100%) 

(9) 

(2) (5) (4) 

1 (20%) 

1 (20%) 

1 (20%) 

1 (20%) 

1 (50%) 2 (40%) 2 (50%) 

1 (50%) 2 (50%) 

(10) (10) (8) 

1 (13%) 

1 (10%) 2 (20%) 2 (25%) 

Hyperplasia, lymphoid 

Lymph node, mesenteric 

Hematopoietic System 

Spleen 

Cyst 

Hyperplasia, lymphoid 

Hematopoietic cell proliferation 

Cyst 

Thymus 

Hyperplasia, lymphoid 

None 

Integumentary System 

None 

Musculoskeletal System 

Mineralization 

Brain 

Nervous System 
184 Methylphenidate Hydrochloride, NTP TR 439 

of Methylphenidate Hydrochloride (continued) 

Summary of the Incidence of Nonneoplastic Lesions in Male Mice in the 2-Year Feed Study 

TABLE C5 

0 PPm 50 PPm 250 PPm 500 ppm 

- 

Nose 

Respiratory System 

15-Month Interim Evaluation (continued) 

(10) (10) (10) (10) 

Inflammation, chronic 8 (80%) 8 (80%) 8 (80%) 7 (70%) 

None ' 

Special Senses System 

Kidney 

Urinary System 

Renal tubule, regeneration 

Mineralization 

casts 

Inflammation, chronic, focal 

Urinary bladder 

2-Year Study 

Intestine large, cecum 

Ulcer 

Gallbladder 

Alimentary System 

Hyperplasia, lymphoid 

Intestine small, jejunum 

Hyperplasia, lymphoid 

Inflammation, acute 

Angiectasis 

Hyperplasia, lymphoid 

Ulcer 

Artery, inflammation, acute 

Thrombosis 

Necrosis, focal 

Inflammation, chronic, focal 

Fatty change, focal 

Fatty change 

Eosinophilic focus 

Clear cell focus 

Basophilic focus 

Liver 

Intestine small, ileum 

Mesentery 

Fat, necrosis 

Mineralization 

Hemorrhage, focal 

Cyst 

Inflammation, chronic, focal 

Hyperplasia, focal 

Salivary glands 

Pancreas 

(48) 

(48) 

(46) 

1 (2%) 

3 (6%) 

33 (69%) 

1 (2%) 

(50) 

(47) 

1 (2%) 

4 (8%) 

2 (4%) 

7 (14%) 

6 (12%) 

4 (8%) 

1 (2%) 

3 (6%) 

1 (2%) 

1 (100%) 

(47) 

(48) 

(49) 

18 (37%) 

1 (2%) 

1 (2%) 

(48) 

(50) 

2 (4%) 

2 (4%) 

7 (14%) 

8 (16%) 

3 (6%) 

1 (2%) 

1 (2%) 

2 (67%) 

(50) 

(49) 

1 (2%) 

2 (4%) 

(47) 

(48) 

(44) 

2 (4%) 

23 (48%) 

(1) 

1 (100%) 

15 (30%) 

14 (28%) 

6 (12%) 

1 (2%) 

1 (2%) 

1 (2%) 

2 (4%) 

6 (12%) 

(2) 

1 (50%) 

1 (50%) 

(50) 

(50) 
Lesions in Male Mice 185 

of Methylphenidate Hydrochloride (continued) 

Summary of the Incidence of Nonneoplastic Lesions in Male Mice in the 2-Year Feed Study 

TABLE C5 

%Year Study (continued) 

Stomach, forestomach 

Alimentary System (continued) 

Ulcer 

Hyperkeratosis, focal 

Foreign body 

Mucosa, hyperplasia, focal 

Inflammation, chronic 

Inflammation, acute 

Hyperplasia 

Erosion 

Stomach, glandular 

Pigmentation, focal 

Hyperkeratosis, focal 

Hemorrhage, focal 

Tongue 

2 (4%) 

1 (2%) 

(3) 

1 (33%) 

1 (33%) 

1 (2%) 

1 (2%) 1 (2%) 

(1) 

1 (100%) 

1 (2%) 

2 (4%) 

2 (4%) 

(47) 

2 (4%) 

(2) 

1 (50%) 

1 (50%) 

Heart 

Cardiovascular System 

Ventricle, hypertrophy 

Mineralization 

Inflammation, chronic, focal 

Endocrine System 

Capsule, hyperplasia, focal 

Capsule, hyperplasia 

Hyperplasia, focal 

Fibrosis 

Atrophy 

Adrenal cortex 

Hyperplasia, focal 

Hyperplasia 

Adrenal medulla 

Hyperplasia 

Atrophy 

Islets, pancreatic 

Pars distalis, cyst 

Pituitaly gland 

Follicular cell, hyperplasia 

Follicle, cyst 

Thyroid gland 

(49) 

1 (2%) 

13 (27%) 

1 (2%) 

(50) 

18 (36%) 

(50) 

(48) 

2 (4%) 

1 (2%) 

1 (2%) 

(49) 

16 (33%) 

1 (2%) 

1 (2%) 

(48) 

(48) 

22 (46%) 

(50) 

(48) 

1 (2%) 

1 (2%) 

15 (30%) 

(50) 

1 (2%) 

1 (2%) 

13 (26%) 

(50) 

1 (2%) 

17 (34%) 

(44) 

None 

General Body System 
186 Methylphenidate Hydrochloride, NTP TR 439 

of Methylphenidate Hydrochloride (continued) 

Summary of the Incidence of Nonneoplastic Lesions in Male Mice in the 2-Year Feed Study 

TABLE C5 

Atrophy 

Epididymis 

Genital System 

Spermatocele 

Inflammation, chronic 

Inflammation, chronic 

Inflammation, acute 

Infiltration cellular, plasma cell 

Hemorrhage, focal 

Dilatation 

Depletion cellular 

Cyst 

Atrophy 

Prostate 

Fibrosis 

Dilatation 

Depletion cellular 

Seminal vesicle 

Seminiferous tubule, atrophy 

Interstitial cell, hyperplasia 

Hypospermia 

Preputial gland 

Testes 

9 (18%) 

6 (12%) 

(50) 

(50) 

5 (10%) 

4 (8%) 

(50) 

1 (2%) 

1 (2%) 

(50) 

24 (48%) 

40 (80%) 

8 (16%) 

8 (16%) 

(50) 

(49) 

5 (10%) 

2 (4%) 

(50) 

1 (2%) 

(49) 

39 (80%) 

24 (49%) 

8 (16%) 

7 (14%) 

(50) 

(49) 

1 (2%) 

1 (2%) 

1 (2%) 

3 (6%) 

2 (4%) 

7 (14%) 

(50) 

(49) 

32 (65%) 

1 (2%) 

26 (53%) 

1 (2%) 

6 (12%) 

4 (8%) 

(50) 

(48) 

2 (4%) 

1 (2%) 

3 (6%) 

(50) 

2 (4%) 

1 (2%) 

2 (4%) 

Bone marrow 

Hematopoietic System 

Hyperplasia, neutrophil 

Pancreatic, hyperplasia 

Mediastinal, infiltration cellular, plasma 

Myelofibrosis 

Infiltration cellular, plasma cell 

Lymph node, mandibular 

Renal, lymphatic, angiectasis 

Thrombosis 

Infiltration cellular, plasma cell 

Hyperplasia 

Fibrosis 

Congestion 

Lymph node, mesenteric 

Infiltration cellular, plasma cell 

Hyperplasia, lymphoid 

Hematopoietic cell proliferation 

Fibrosis, focal 

Depletion lymphoid 

Congestion 

cell 

Lymph node 

Spleen 

1 (2%) 

(3) 

2 (67%) 

(48) 

(49) 

1 (2%) 

1 (2%) 

2 (4%) 

2 (4%) 

5 (10%) 

1 (2%) 

(50) 

6 (12%) 

(49) 

1 (2%) 

7 (14%) 

3 (6%) 

(45) 

(49) 

1 (2%) 

3 (7%) 

(49) 

4 (8%) 

1 (2%) 

9 (18%) 

2 (4%) 

1 (2%) 

1 (50%) 

1 (2%) 

1 (2%) 

(47) 

(49) 

(50) 

1 (2%) 

7 (14%) 

1 (2%) 

1 (2%) 
Lesions in Male Mice 187 

of Methylphenidate Hydrochloride (continued) 

Summary of the Incidence of Nonneoplastic Lesions in Male Mice in the 2-Year Feed Study 

TABLE C5 

0 PPm 50 PPm 250 ppm 500 ppm 

Skin 

Integumentary System 

&Year Study (continued) 

Ulcer 

Inflammation, chronic 

(50) 

1 (2%) 

Bone 

Musculoskeletal System 

Hyperostosis (50) 

1 (2%) 

(50) 

1 (2%) 

Nervous System 

Mineralization 

Hemorrhage, focal 

Compression 

Brain (50) 

31 (62%) 34 (68%) 30 (60%) 

Lung 

Respiratory System 

Alveolar epithelium, hyperplasia 

Inflammation, chronic 

Infiltration cellular, histiocyte 

Hemorrhage, focal 

Congestion 

Angiectasis 

Olfacto~y epithelium, hyperplasia 

Inflammation, chronic, focal 

Inflammation, chronic 

Nose 

(50) 

1 (2%) 

5 (10%) 

1 (2%) 

1 (2%) 

1 (2%) 

1 (2%) 

3 (6%) 

(50) (50) 

1 (2%) 

47 (94%) 45 (90%) 

1 (2%) 

1 (2%) 

1 (2%) 

44 (88%) 

4 (8%) 3 (6%) 

(50) (50) 

45 (90%) 

1 (2%) 

Hyperplasia 

Harderian gland 

Special Senses System 

(2) 

1 (50%) 

Kidney 

Urinary System 

Renal tubule, regeneration 

Renal tubule, degeneration, granular 

Nephropathy 

Mineralization 

Metaplasia, osseous 

Inflammation, chronic, focal 

Infarct 

Hyperplasia, lymphoid 

Hemorrhage 

Glomerulosclerosis 

Crst 

(50) 

1 (2%) 

1 (2%) 

1 (2%) 

2 (4%) 

14 (28%) 

30 (60%) 

1 (2%) 

1 (2%) 

(50) 

1 (2%) 

1 (2%) 

1 (2%) 

1 (2%) 

2 (4%) 

14 (28%) 

28 (56%) 

(50) 

1 (2%) 

1 (2%) 

1 (2%) 

33 (66%) 

2 (4%) 

1 (2%) 

1 (2%) 

13 (26%) 

1 (2%) 

1 (2%) 

18 (36%) 

30 (60%) 

2 (4%) 

1 (2%) 
188 Methylphenidate Hydrochloride, NTP TR 439 

of Methylphenidate Hydrochloride (continued) 

Summary of the Incidence of Nonneoplastic Lesions in Male Mice in the 2-Year Feed Study 

TABLE C5 

Urinary bladder 

Urinary System (continued) 

2-Year Study (continued) 

Perivascular, inflammation, chronic 

Ectasia 

Concretion 

Calculus micro observation only 
189 

OF METHYLPHENIDATE HYDROCHLORIDE 

SUMMARY OF LESIONS IN FEMALE MICE 

APPENDIX D 

IN THE 2-YEAR FEED STUDY 

TABLE D2 Individual Animal Tumor Pathology of Female Mice 

in the 2-Year Feed Study of Methylphenidate Hydrochloride 

TABLE Dl Summary of the Incidence of Neoplasms in Female Mice 

in the 2-Year Feed Study of Methylphenidate Hydrochloride 

TABLE D3 Statistical Analysis of Primary Neoplasms in Female Mice 

in the 2-Year Feed Study of Methylphenidate Hydrochloride 

in the 2-Year Feed Study of Methylphenidate Hydrochloride 

TABLE D5 Summary of the Incidence of Nonneoplastic Lesions in Female Mice 

TABLE D4 Historical Incidence of Liver Neoplasms in Untreated Female B6C3Fl Mice 

.................... 

218 

196 

191 

224 

223 

.................... 

.................... ........ 

.................... 
Methylphenidate Hydrochloride, NTP TR 439 
Lesions in Female Mice 191 

Summary of the Incidence of Neoplasms in Female Mice in the 2-Year Feed Study of Methylphenidate Hydrochloridea 

TABLE Dl 

0 PPm 50 PPm 250 ppm 500 ppm 

Early deaths 

IS-Montf~ intairn evalkaticRI 

9-"iintcrlmevabrmionb 

Animals initially in study 

Disposition Summary 

Natural deaths 

Moribund 

Accidental deaths 

Terminal sacrifice 

Died last week of study 

survivors 

Animals examined microscopically 

Missing 

10 

10 

69 

5 

6 

1 

36 

1 

69 

10 

9 

69 

7 

7 

1 

34 

1 

68 

10 

10 

70 

6 

7 

37 

70 

10 

10 

70 

6 

44 

70 

15-Month Interim Evaluation 

Liver 

Alimentary System' 

(101 (10) (10) (10) 

Hemangioma 1 (10%) 1 (10%) 1 (10%) 1 (10%) 

Pituitary gland 

Endocrine System 

Pars distaliis, adenoma 

Cystadenoma 

Genital System 

Ovary 

Lung 

Respiratory System 

Alveolarbronchiolar adenoma 

Intestine small, duodenum 

Intestine large, cecum 

Intestine large, rectum 

Gallbladder 

Alimentary System 

2-Year Study 

Adenocarcinoma 

Intestine small, jejunum 

Polyp adenomatous 

Intestine small, ileum 

Hemangioma 
192 Methylphenidate Hydrochloride, NTP TR 439 

TABLE Dl 

(continued) 

Summary of the Incidence of Neoplasms in Female Mice in the 2-Year Feed Study of Methylphenidate Hydrochloride 

Liver 

Alimentary System (continued) 

ZYear Study (continued) 

Histiocytic sarcoma, metastatic, uterus 

Histiocytic sarcoma 

Hepatocellular adenoma, multiple 

Hepatocellular adenoma 

Hepatocellular carcinoma, multiple 

Hepatocellular carcinoma 

Hemangiosarcoma 

Hemangioma 

Mesentery 

Stomach, forestomach 

Salivary glands 

Pancreas 

Sarcoma 

Stomach, glandular 

Squamous cell papilloma 

(49) 

15 (30%) 

13 (26%) 

1 (2%) 

5 (10%) 

Adrenal cortex 

Endocrine System 

Adenocarcinoma, metastatic, uterus 

Pheochromocytoma malignant 

Capsule, adenoma 

Alveolarbronchiolar carcinoma, metastatic, 

Adenoma 

Islets, pancreatic 

Pheochromocytoma benign 

Pars intermedia, adenoma 

Pars distalis, adenoma 

Pituitary gland 

Follicular cell. carcinoma 

Follicular cell, adenoma 

Adrenal medulla 

lung 

Thyroid gland 

(49) (49) (50) 

1 (2%) 

1 (2%) 

(49) 

1 (2%) 

(49) 

(49) 

2 (4%) 

15 (31%) 

1 (2%) 

(49) (47) (50) 

1 (2%) 

1 (2%) 

(47) 

(50) 

8 (17%) 

4 (8%) 

1 (2%) 

(49) 

(48) 

(48) 

1 (2%) 

7 (15%) 

1 (2%) 

(49) (48) 

6 (13%) 

(49) 

1 (2%) 

Hemangiosarcoma 

Tissue NOS 

General Body System 

(2) 

1 (50%) 
Lesions in Female Mice 193 

(continued) 

Summary of the Incidence of Neoplasms in Female Mice in the 2-Year Feed Study of Methylphenidate Hydrochloride 

TABLE Dl 

0 PPm 50 PPm 250 ppm 500 ppm 

2-Year Study (continued) 

Genital System 

Teratoma NOS 

Histiocytic sarcoma, metastatic, uterus 

Cystadenoma, multiple 

Cystadenoma ovary 

Endometrium, adenocarcinoma 

Polyp stromal 

Leiomyoma 

Histiocytic sarcoma 

Hemangioma 

Uterus 

Bone marrow 

Hematopoietic System 

Histiocytic sarcoma 

Hemangiosarcoma 

Adenocarcinoma, metastatic, uterus 

Lumbar, sarcoma, metastatic, skin 

Lumbar, histiocytic sarcoma, metastatic, 

Histiocytic sarcoma, metastatic, uterus 

Histiocytic sarcoma 

Carcinoma, metastatic, harderian gland 

Lymph node, mandibular 

Histiocytic sarcoma, metastatic, uterus 

Histiocytic sarcoma 

Lymph node, mesenteric 

Histiocytic sarcoma 

Hemangiosarcoma 

Hemangioma 

Histiocytic sarcoma, metastatic, uterus 

Histiocytic sarcoma 

Alveolarbronchiolar carcinoma, metastatic, 

Adenocarcinoma, metastatic, uterus 

Lymph node 

uterus 

Spleen 

Thymus 

lung 

(49) (49) 

1 (2%) 

(7) 

(45) (47) 

(48) 

1 (2%) 

(8) 

1 (13%) 

1 (13%) 

(49) 

1 (2%) 

1 (2%) 

1 (2%) 

1 (2%) 

1 (2%) 

1 (2%) 

1 (2%) 

(47) 

(49) 

(49) 

1 (2%) 

1 (2%) 

1 (2%) 

(50) 

1 (2%) 

(49) 

1 (2%) 

(47) 

(49) 

1 (2%) 

Mammary gland 

integumentary System 

Adenoma 

Adenocarcinoma, metastatic, uterus 

Adenocarcinoma 

Sarcoma 

Histiocytic sarcoma 

Hemangiosarcoma 

Skin 

(40) (43) (46) (44) 

1 (2%) 

1 (2%) 

1 (2%) 

1 (2%) 

1 (2%) 

(49) (49) (50) (50) 

1 (2%) 

1 (2%) 

1 (2%) 
194 Methylphenidate Hydrochloride, NTP TR 439 

0 PPm 50 ppm . 

~ 

250 ppm 500 ppm 

Bone 

Musculoskeletal System 

%Year Study (continued) 

(49) Alveolarbronchiolar carcinoma, metastatic, 

Skeletal muscle 

lung 

(1) 

Brain 

Nervous System 

Adenocarcinoma, metastatic, uterus (50) 

1 (2%) 

Lung 

Respiratory System 

Alveolarbronchiolar carcinoma, metastatic, 

Alveolarbronchiolar carcinoma 

Alvedarbronchiolar adenoma 

Adenocarcinoma, metastatic, uterus 

Osteosarcoma, metastatic, uncertain primary 

Histiocytic sarcoma, metastatic, uterus 

Hepatocellular carcinoma, metastatic, liver 

Carcinoma, metastatic, thyroid gland 

Carcinoma, metastatic, harderian gland 

Histiocytic sarcoma, metastatic, uterus 

Carcinoma, metastatic, harderian gland 

Sarcoma, metastatic, skin 

lung 

site 

Nose 

1 (2%) 

2 (4%) 

1 (2%) 

1 (2%) 

2 (4%) 

4 (8%) 

1 (2%) 

1 (2%) 

1 (2%) 

1 (2%) 

(49) (49) (50) 

1 (2%) 

(50) 

2 (4%) 

1 (2%) 

6 (12%) 

1 (2%) 

1 (2%) 

(50) 

1 (2%) 

Special Senses System 

Carcinoma 

Adenoma 

Harderian gland (2) (1) (4) (5) 

1 (50%) 3 (75%) 

3 (60%) 

1 (20%) 

1 (100%) 

Hemangioma 

Urinary bladder 

Adenocarcinoma, metastatic, uterus 

Kidney 

Urinary System 

(43) 

(49) 

Multiple organsd 

Systemic Lesions 

Lymphoma malignant mixed 

Lymphoma malignant lymphocytic 

Histiocytic sarcoma 

(49) (49) (50) (50) 

2 (4%) 1 (2%) 

1 (2%) 1 (2%) 

11 (22%) 12 (24%) 

2 (4%) 

2 (4%) 

14 (28%) 

3 (6%) 

2 (4%) 

6 (12%) 
Lesions in Female Mice 195 

(continued) 

Summary of the Incidence of Neoplasms in Female Mice in the 2-Year Feed Study of Methylphenidate Hydrochloride 

TABLE Dl 

0 PPm 50 PPm 250 PPJQ 500 PPJQ 

Total animals with primary neoplasmse 

Neoplasm Summary 

2-Year Study (continued) 

15-Month interim evaluation 

2-Year study 

15-Month interim evaluation 

2-Year study 

15-Month interim evaluation 

2-Year study 

15-Month interim evaluation 

2-Year study 

2-Year study 

2-Year study 

2-Year study 

2-Year study 

Total primary neoplasms 

Total animals with benign neoplasms 

Total benign neoplasms 

Total animals with malignant neoplasms 

Total metastatic neoplasms 

Total animals with metastatic neoplasms 

Total malignant neoplasms 

Total animals with malignant neoplasms 

of uncertain primary site 

2-Year study 

Total animals with uncertain neoplasms 

benign or malignant 

2-Year study 

2-Year study 

Total uncertain neoplasms 

34 

3 

35 

1 

40 

1 

41 

3 

50 

3 

30 

1 

68 

1 

86 

3 

57 

1 

19 

3 1% 

25 35 

3 

25 

3 

46 

1 

54 

3 

35 

1 

22 

21 

20 16 26 

24 22 32 

2 1 4 3 

2 1 15 11 

1 

1 

1 

e Primary neoplasms: all neoplasms except metastatic neoplasms 

Number of animals with any tissue examined microscopically 

No neoplasms were observed at any other site in any animal at the 15-month interim evaluation. 

No neoplasms were observed at any site in any animal at the 9-month interim evaluation. 

a Number of animals examined microscopically at site and number of animals with neoplasm 
196 Methylphenidate Hydrochloride, NTP TR 439 

Individual Animal Tumor Pathology of Female Mice in the 2-Year Feed Study of Methylphenidate Hydrochloride: 0 ppm 

TABLE D2 

I 

0355666667777777777777777 

Number of Days on Study 6478227880004444444444444 

0642110835702983458136702 

3333333'333333323333333333 

7811183458886677777777777 

Carcass ID Number 022340154334.0090000111122' 

Intestine small, duodenum 

Intestine large, cecum 

Intestine large, rectum 

Intestine large, colon 

Gallbladder 

Esophagus 

Alimentary System 

Liver 

Intestine small, ileum 

Intestine small, jejunum 

Polyp adenomatous 

Hepatocellular adenoma, multiple 

Hepatocellular adenoma 

Hepatocellular carcinoma, multiple 

Hepatocellular carcinoma 

Hemangiosarcoma 

Hemangioma 

Mesentery 

Stomach, forestomach 

Salivary glands 

Pancreas 

Sarcoma 

Tongue 

Stomach, glandular 

Squamous cell papilloma 

++A++A++A++++++++++++++++ 

++A+++++A++++++++++++++++ 

++A++A++A++++++++++++++++ 

++A++A++A++++++++++++++++ 

++A++AA+A++++++++++++++++ 

......................... 

X 

......................... 

++A++AA+A++++++++++++++++ 

++A++AA+A++++++++++++++++ 

X 

X 

X 

X 

X 

+ 

++A++++M+++++++++++++++++ 

.......................... 

++A++++++++++++++++++++++ 

++A++++++++++++++++++++++ 

X 

+ + 

Cardiovascular System 

Heart +++++++++++++M+++++++++++ 

Islets, pancreatic 

Adrenal medulla 

Adrenal cortex 

Endocrine System 

Pituitary gland 

Parathyroid gland 

Adenoma 

++A++++++++++++++++++++++ 

......................... 

......................... 

X 

++++++++M++++++++++++++++ 

M+MM+++M+++++M+M++M++++++ 

Pars intermedia, adenoma 

Pals distalis, adenoma X X X 

Hemangiosarcoma 

General Body System 

Thyroid gland .......................... 

Tissue NOS 

A: Autolysis precludes examination 

f: Tissue examined microscopically 

I: Insufficient tissue 

M. Missing tissue 

Blank Not examined 

X: Lesion present 
Lesions in Female Mice 197 

(continued) 

Individual Animal Tumor Pathology of Female Mice in the 2-Year Feed Study of Methylphenidate Hydrochloride: 0 ppm 

TABLE D2 

111111111111111111111111 

444444444444444444444444 

111111117111111111111111 

Number of Days on Study 

Carcass ID Number 

333333333333333333333333 Total 

222333333444445555666666 Tissues/ 

358013689245680569012345 Tumors 

Intestine small, duodenum 

Intestine large, cecum 

Intestine large, rectum 

Intestine large, colon 

Gallbladder 

Esophagus 

Alimentary System 

Liver 

Intestine small, ileum 

Intestine small, jejunum 

Polyp adenomatous 

Hepatocellular adenoma, multiple 

Hepatocellular adenoma 

Hepatocellular carcinoma, multiple 

Hepatocellular carcinoma 

Hemangiosarcoma 

Hemangioma 

Pancreas 

Sarcoma 

Mesentery 

Tongue 

Stomach, glandular 

Stomach, forestomach 

Salivary glands 

Squamous cell papilloma 

........................ 

........................ 

........................ 

........................ 

+++M++++++++++++++++++++ 

........................ 

........................ 

........................ 

........................ 

X X 

X X X 

X 

++ 

X 

++ 

X 

+ 

........................ 

......................... 

........................ 

........................ + 3 

48 

1 

41 

49 

48 

1 

6 

2 

4 

2 

3 

1 

1 

49 

45 

45 

1 

46 

41 

46 

46 

44 

49 

Cardiovascular System 

Heart ........................ 48 

Islets, pancreatic 

Adrenal medulla 

Adrenal cortex 

Endocrine System 

Pituitary gland 

Parathyroid gland 

Adenoma 

Pars intermedia, adenoma 

Pars distalis, adenoma 

Thyroid gland 

........................ 48 

........................ 49 

........................ 49 

........................ 48 

+++M+M+++M++++++++++++++ 39 

1 

........................ 49 

1 

I 

X 

X X X 

X 

Hemangiosarcoma 

General Body System 

Tissue NOS 

X 

+ + 

1 

2 
198 Methylphenidate Hydrochloride, NTP TR 439 

Number of Days on Study 

7811183458886677777777777 

6478227880004444444444444 

0355666667777777777777777 

0223401543340090000111122 

3333333333333323333333333 

Carcass ID Number 

0642110835702983458136702 

Genital System 

Clitoral gland 

ovary 

Teratoma NOS 

Cystadenoma 

Polyp stromal 

Leiomyoma 

Histiocytic sarcoma 

Hemangioma 

Uterus 

+++++++++++M+M+++++++++++ 

+++++++M+M++M+++++++M++ 

X ......................... .. 

X 

X 

X 

Hematopoietic System 

Lymph node 

Bone marrow ......................... ++ -+ + 

Spleen 

Lymph node, mesenteric 

Lymph node, mandibular 

Hemangiosarcoma 

Thymus 

++++++++++M++++++++++++++ 

++M++M++M++++++++++++++++ 

......................... 

++++++M++++++M+++++++++++ 

X 

Skin 

Mammary gland 

Integumentary System 

......................... 

++M+++++++++M+++M++M+++++ 

Musculoskeletal System 

Skeletal muscle 

Bone 

+ ......................... 

Nervous System 

Brain 

Respiratory System 

Lung +++++++++++++M+++++++++++ 

Hepatocellular carcinoma, metastatic, 

Alveolaribronchiolar adenoma 

Trachea 

NOS2 

liver 

......................... 

......................... 

Harderian gland 

Ear 

Special Senses System 

~ ~_____ 

Adenoma 

+ 

t 

Urinary bladder 

Kidney 

Urinary System 

++A++AA+A++++++++++++++++ 

......................... 
Lesions in Female Mice 199 

(continued) 

Individual Animal Tumor Pathology of Female Mice in the 2-Year Feed Study of Methylphenidate Hydrochloride: 0 ppm 

TABLE D2 

Number of Days on Study 

777777777777777777777777 

444444444444444444444444 

777777777777777777777777 

333333333333333333333333 Total 

222333333444445555666666 Tissues/ 

358013689245680569012345 Tumors 

Carcass ID Number 

Genital System 

Clitoral gland ++++++++M+++++++++++++++ 42 

ovary 

Teratoma NOS 

Cystadenoma 

Polyp stromal 

Leiomyoma 

Histiocytic sarcoma 

Hemangioma 

Uterus 

1 

1 

++++++++M+++++++++++++++ 46 

2 

1 

........................ 49 

X 

X 

X 

X 2 

1 

Hematopoietic System _____~~~ _____~~~~ 

Spleen 

Lymph node, mesenteric 

Lymph node, mandibular 

Lymph node 

Bone marrow 

Hemangiosarcoma 

Thymus ........................ 47 

2 

......................... 48 

+++++++M++++++++++++++++ 45 

.......................... 48 

7 

........................ 49 

+ ++ 

X 

Skin 

Mammary gland 

Integumentary System 

+++++++++M++++MM++M+M+++ 40 

........................ 49 

Musculoskeletal System 

Skeletal muscle 

Bone 

1 

........................ 49 

Nervous System 

Brain ........................ 49 

Respiratory System 

Lung 

1 

........................ 48 

........................ 49 

........................ 49 

2 

Hepatocellular carcinoma, metastatic, 

Alveolarbronchiolar adenoma X 

Trachea 

Nose 

liver X x 

Harderian gland 

Ear 

Special Senses System 

1 

2 

1 

X 

+ 

Adenoma 

Urinary bladder 

Kidney 

Urinary System 

........................ 49 

+++++++++M+++++M++++++++ 43 
200 Methylphenidate Hydrochloride, NTP TR 439 

(continued) 

Individual Animal Tumor Pathology of Female Mice in the &Year Feed Study of Methylphenidate Hydrochloride: 0 ppm 

TABLE D2 

Number of Days on Study 

7811183458886677777777777 

6478227880004444444444444 

0355666667777777777777777 

Carcass ID Number 

0642110835702983458136702 

0223401543340090000111122 

3333333333333323333333333 

Systemic Lesions 

Multiple organs 

X 

......................... 

Lymphoma malignant mixed 

Lymphoma malignant lymphocytic 

Histiocytic sarcoma 

X xxx xx 

X 
Lesions in Female Mice 201 

(continued) 

Individual Animal Tumor Pathology of Female Mice in the 2-Year Feed Study of Methylphenidate Hydrochloride: 0 ppm 

TABLE D2 

Number of Days on Study 

777777777777777777777777 

444444444444444444444444 

777777777777777777777777 

333333333333333333333333 Total 

222333333444445555666666 Tissues/ 

358013689245660569012345 Tumors 

Carcass ID Number 

Systemic Lesions 

Multiple organs 

11 

1 

2 

........................ 49 

Lymphoma malignant mixed 

Lymphoma malignant lymphocytic 

Histiocytic sarcoma X 

X xx x X 
202 Methylphenidate Hydrochloride, NTP TR 439 

Individual Animal Tumor Pathology of Female Mice in the 2-Year Feed Study of Methylphenidate! Hydrochloride: 50 ppm 

TABLE D2 

358128358100901333333333 

045968022899934444444444 

111345666666677777777777 

685299971444650891278926 

021189092813638667777788 

444433434344343333333333 

Number of Days on Study 

Carcass ID Number 

Intestine small, jejunum 

Intestine small, duodenum 

Intestine large, cecum 

Intestine large, rectum 

Intestine large, colon 

Gallbladder 

Esophagus 

Alimentary System 

Liver 

Intestine small, ileum 

Adenocarcinoma 

++A++AA+A++A++++++++++++ 

A+A++AA+A++A++++++++++++ 

++A++AA+A++A++++++++.++++ 

+++++AA+A+++++++++++++++ 

+++++AA+A+++++++++++++++ 

A+A++AAAAM+A++M+++++++++ 

++++++M+++++++++++++++++ 

++++++++A+++++++++++++++ 

A+A++AAAA++A++++++++++++ 

Histiocytic sarcoma 

Hepatocellular adenoma 

Hepatocellular carcinoma 

Hemangiosarcoma X 

X 

X X. X 

X 

Stomach, forestomach 

Salivary glands 

Pancreas 

Stomach, glandular 

........................ 

........................ 

++++++++A+++++,++++++++++ 

A+++++++A++A++++++++++++ 

Squamous cell papilloma X 

Cardiovascular System 

Heart ........................ 

Islets, pancreatic 

Adrenal medulla 

Adrenal cortex 

Endocrine System 

Pituitary gland 

Parathyroid gland 

Adenoma 

Thyroid gland 

++++++++A+++++++++++++++ 

+++++M++A+++++++++++++++ 

++++++++A+++++++++++++++ 

++++++M+++++++++++++++++ 

X xx X 

........................ 

+MMM++MMM++MM+M++++++M++ 

X X 

Follicular cell, adenoma 

Pars distalis, adenoma 

General Body System 

ovary 

Genital System 

None 

Clitoral gland ++M+++++++++M++++M++ 

++++++++A+++++++++++++++ 

Teratoma NOS 

Cystadenoma, multiple 

Cystadenoma xx X 

X 

........................ 

X 

Uterus 
Lesions in Female Mice 203 

(continued) 

Individual Animal Tumor Pathology of Female Mice in the 2-Year Feed Study of Methylphenidate Hydrochloride: 50 ppm 

TABLE D2 

3336666666666666666666666 

4444444444444444444444444 

1111111111111111111111111 

3343333444444444444444444 Total 

8908999000000011122222233 Tissues1 

1608245123451816134567923 Tumors 

Number of Days on Study 

Carcass ID Number 

Intestine small, jejunum 

Intestine small, duodenum 

Intestine large, cecum 

Intestine large, rectum 

Intestine large, colon 

Gallbladder 

Esophagus 

Alimentary System 

Liver 

Intestine small, ileum 

Adenocarcinoma 

Histiocytic sarcoma 

Hepatocellular adenoma 

Hepatocellular carcinoma 

Hemangiosarcoma 

Stomach, forestomach 

Salivary glands 

Pancreas 

Stomach, glandular 

Squamous cell papilloma 

......................... 

......................... 

......................... 

......................... 

......................... 

......................... 

......................... 

X 

......................... 

......................... 

xx x 

X 

X xx X 

X 

......................... 

......................... 

......................... 

......................... 46 

1 

49 

49 

48 

1 

10 

3 

1 

48 

42 

1 

44 

43 

44 

46 

46 

40 

48 

Cardiovascular System 

Heart ......................... 49 

Adrenal medulla 

Adrenal cortex 

Endocrine System I 

......................... 48 

......................... 41 

Islets, pancreatic 

Pituitary gland 

Parathyroid gland 

Adenoma 

Thyroid gland 

Follicular cell, adenoma 

Pars distalis, adenoma 

X X xx X 6 

......................... 48 

xx 10 

+++++++++++++++++++M+++++ 48 

++++++M+++’++M++++++MMM++M 33 

2 

......................... 48 

xx x x 

X 

General Body System 

0-v 

Genital System 

None 

Clitoral gland +++++M+++++++++++++++++++ 41 

......................... 48 

X 4 

......................... 49 

1 

1 

Teratoma NOS 

Cystadenoma, multiple 

Cystadenoma 

Uterus 
204 Methylphenidate Hydrochloride, NTP TR 439 

TABLE D2 

(continued) 

Individual Animal Tumor Pathology of Female Mice in the 2-Year Feed Study of Methylphenidate Hydrochloride: 50 ppm 

358128358100901333333333 

045968022899934444444444 

111345666666677777777777 

Number of Days on Study 

685299971444650891278926 

021189092813638667777788 

444433434344343333333333 

Carcass ID Number 

Hematopoietic System 

Bone marrow 

Spleen 

Lymph node, mesenteric 

Lymph node, mandibular 

Lymph node 

Histiocytic sarcoma 

Histiocytic sarcoma 

Thymus 

........................ X 

+++ + 

++++++++A+++++++++++++++ 

++A+++++A+++++++++++++++ 

++++++++AM++++++++++M+++ 

++++++++A++++M++++++++++ 

X 

Integumentary System 

Skin 

Mammary gland 

Sarcoma 

........................ 

++++++M++++++M+M+++++M++ 

Musculoskeletal System 

Bone ........................ 

Nervous System 

Spinal cord 

Brain ........................ + 

Respiratory System 

Lung ........................ 

Osteosarcoma, metastatic, uncertain 

Alveolarbronchiolar adenoma X 

primary site X 

Trachea 

NOS?. ........................ 

........................ 

Carcinoma 

Harderian gland 

Special Senses System 

Eye + 

X 

+ 

Urinary bladder 

Kidney 

Urinary System 

A+A++AAAA++A++A+++++++++ 

........................ 

Systemic Lesions 

Multiple organs ........................ Histiocytic sarcoma X 

Lymphoma malignant mixed 

Lymphoma malignant lymphocytic X 

xx X X 
Lesions in Female Mice 205 

(continued) 

Individual Animal Tumor Pathology of Female Mice in the 2-Year Feed Study of Methylphenidate Hydrochloride: 50 ppm 

TABLE D2 

1111111111111111111111111 

Number of Days on Study 

3336666666666666666666666 

4444444444444444444444444 

Carcass ID Number 

3343333444444444444444444 Total 

8908999000000011122222233 Tissues/ 

I608245123451816134561923 Tumors 

Hematopoietic System 

Bone marrow ......................... 49 

Histiocytic sarcoma 

Spleen 

Lymph node, mesenteric 

Lymph node, mandibular 

Lymph node 

Histioqtic sarcoma 

Thymus ......................... 41 

1 

48 

......................... 41 

+++++++++M+++++++++++++++ 45 

1 

1 

+ ++ 

.......................... 

Skin 

Mammary gland 

Integumentary System 

Sarcoma 1 

......................... 49 

++++++-t++++M+++++++++M+++ 43 

X 

Musculoskeletal System 

Bone ......................... 49 

Nervous System 

Respiratory System 

Spinal cord 

Brain 

1 

......................... 49 

Lung 

1 

......................... 49 

......................... 49 

......................... 49 

1 

Osteosarcoma, metastatic, uncertain 

Aiveolar/bkchiolar adenoma 

primary site 

Trachea 

Nose 

Carcinoma 

Harderian gland 

Special Senses System i 

Eye 

1 

1 

1 

Urinary bladder 

Kidney 

Urinary System 

......................... 48 

+++++++++++++++++++M+++++ 40 

Systemic Lesions 

Multiple organs 

12 

1 

1 

......................... 49 

Lymphoma malignant mixed 

Lymphoma malignant lymphocytic 

Histiocytic sarcoma 

xxx X xx x x 
206 Methylphenidate Hydrochloride, NTP TR 439 

TABLE D2 

Individual Animal Tumor Pathology of Female Mice in the 2-Year Feed Study of Methylphenidate Hydrochloride: 250 ppm 

7398766975898222222222222 

5867058890012444444444444 

0145666667777177777777777 

Number of Days on Study 

4444444444444444444444444 

Carcass ID Number 

1925928806778359234561303 

5586665447436444555556678 

Intestine small, jejunum 

Intestine small, duodenum 

Intestine large, cecum 

Intestine large, rectum 

Intestine large, colon 

Gallbladder 

Esophagus 

Alimentary System 

A+++AA+++A+A+++++++++++++ 

A+++AA+++A+A+++++++++++++ 

A+++AA+++A+A+++++++++++++ 

++++AA+++++A+++++++++++++ 

++++AA+++++A+++++++++++++ 

A++MAA+++A+A+++++++M+++++ 

......................... 

Hemangioma X 

Intestine small, ileum 

Histiocytic sarcoma, metastatic, 

Histiocytic sarcom' 

Hepatocellular adenoma, multiple 

Hepatocellular adenoma 

Hepatocellular carcinoma 

Hemangiosarcoma 

Liver 

Pancreas 

Mesentery 

uterus 

++++A++++++++++++++++++++ 

A+++AA+++A+A+++++++++++++ 

x xx 

X 

xx 

X 

X 

x + 

++++A++++++++++++++++++++ 

Salivary glands ......................... 

Stomach, glandular 

Stomach: forestomach 

Squamous cell papilloma 

++++AA+++++++++++++++++++ 

......................... X 

Cardiovascular System 

Heart ......................... 

Adrenal cortex 

Endocrine System 

++++A++++++++++++++++++++ 

X 

++++A++++++++++++++++++++ 

Alveolarbronchiolar carcinoma, 

metastatic, lung 

Islets, pancreatic 

Pheochromocytoma malignant 

Adrenal medulla 

Pituitary gland 

Parathyroid gland 

Adenoma 

Thyroid gland ++++M++++++++++++++++++++ 

......................... 

+++MMMM++++++M++++++++M++ 

......................... xx 

Follicular cell, carcinoma 

Pars distalii, adenoma xx x xx X 

General Body System 

None 
Lesions in Female Mice 207 

(continued) 

Individual Animal Tumor Pathology of Female Mice in the 2-Year Feed Study of Methylphenidate Hydrochloride: 250 ppm 

TABLE D2 

2222222222233333333333333 

4444444444444444444444444 

7777777777777777777777777 

Number of Days on Study 

Carcass ID Number 

4444444445544444444444455 Total 

8888999990033345567179900 Tissues/ 

4579017894568940770354612 Tumors 

Intestine small, jejunum 

Intestine small, duodenum 

Intestine large, cecum 

Intestine large, rectum 

Intestine large, colon 

Gallbladder 

Esophagus 

Alimentary System 

Intestine small, ileum 

Histiocytic sarcoma, metastatic, 

Histiocytic sarcoma 

Hepatocellular adenoma, multiple 

Hepatocellular adenoma 

Hepatocellular carcinoma 

Hemangiosarcoma 

Liver 

Hemangioma 

UteNS 

Stomach, forestomach 

Salivary glands 

Pancreas 

Mesentery 

Stomach, glandular 

Squamous cell papilloma 

......................... 45 

......................... 45 

......................... 45 

......................... 47 

......................... 47 

......................... 43 

......................... 50 

......................... 49 

......................... 45 

1 

1 

3 

7 

2 

X 1 

X 

X X 

X X 

1 

1 

......................... 49 

......................... 50 

......................... 49 

......................... 48 

1 

Cardiovascular System 

Heart ......................... 50 

Adrenal cortex 

Endocrine System 

49 

1 

......................... 49 

Alveolar/bronchiolar carcinoma, 

metastatic, lung 

Adrenal medulla ......................... 

Islets, pancreatic 

Pheochromocytoma malignant 

Pituitary gland 

Parathyroid gland 

Adenoma 

Thyroid gland 

Follicular cell, carcinoma 

Pars distalis, adenoma 

X 

1 

......................... 49 

xxx xx. x X X 15 

+++++++++++++++++++++++M+ 49 

++++M+++M+M+++++++++++++M 40 

2 

......................... 49 

1 

X 

X 

General Body System 

None 
208 Methylphenidate Hydrochloride, NTP TR 439 

TABLE D2 

(continued) 

Individual Animal Tumor Pathology of Female Mice in the 2-Year Feed Study of Methylphenidate Hydrochloride: 250 ppm 

73987669,75898222222222222 

5867058890.012444444444444 

014566666777777777'7777777 

Number of Days on Study 

Carcass ID Number 

1925928806778359234561383 

5586665'447436444555556678 

444444444'444444444'4444444 

maIy 

Genital System 

Clitoral gland 

++++M++++++++++++++++++++ 

++A++++++++++++++++++++ 

Histiocytic sarcoma, metastatic, 

Cystadenoma 

uterus X 

Uterus ......................... 

Polyp stromal 

Histiocytic sarcoma 

Hemangioma X 

X 

X X 

Histiocytic sarcoma 

Lumbar, sarcoma, metastatic, skin 

Lumbar, histiocytic sarcoma, 

Hemangiosarcoma 

Hematopoietic System 

Histiocytic sarcoma, metastatic, 

Lymph node 

Bone marrow 

Lymph node, mandibular 

metastatic, uterus 

uterus 

Histiocytic sarcoma, metastatic, 

Histiocytic sarcoma 

Lymph node, mesenteric 

Spleen , 

uterus 

Histiocytic sarcoma 

Hemangiosarcoma 

Hemangioma 

Histiocytic sarcoma, metastatic, 

Histiocytic sarcoma 

metastatic, lung 

Alveolar/bronchiolar carcinoma, 

Thymus 

uterus 

X 

++++AA+++++++++++++++++++ 

++ + 

X 

++++A++++++++++++++++++++ 

X 

X 

++++A+++++++M+++++++-+++++ 

X 

X 

++++M++++++++++++++++++++ 

++++M++++++++++++++++++++ 

X 

X 

X 

X 

X 

Mammary gland 

Integumentary System 

Adenoma 

Adenocarcinoma 

Skin 

+M++M++++++++++++++++++++ 

X 

......................... 

Sarcoma 

Hemangiosarcoma X .. 
Lesions in Female Mice 209 

(continued) 

Individual Animal Tumor Pathology of Female Mice in the 2-Year Feed Study of Methylphenidate Hydrochloride: 250 ppm 

TABLE D2 

‘2222222222233333333333333 

4444444444444444444444444 

7777777777777777777777777 

4444444445544444444444455 Total 

8888999990033345567779900 Tissues/ 

4579017894568940770354612 Tumors 

Number of Days on Study 

Carcass ID Number 

ovary 

Genital System 

Clitoral gland 

Histiocytic sarcoma, metastatic, 

Cystadenoma 

uterus 

Uterus 

Polyp stromal 

Histiocytic sarcoma 

Hemangioma 

1 

......................... 49 

++++M+M++++++++M+++++++++ 44 

X 

......................... 49 

1 

X X X X 6 

1 

1 

Hemangiosarcoma 

Hematopoietic System 

Lymph node 

Bone mam 

8 

1 

......................... 48 

1 

......................... 49 

1 

1 

1 

++++++++++++++++M++++++++ 47 

1 

......................... 49 

1 

1 

1 

......................... 49 

1 

++ ++ + 

’ Lumbar, histiocytic sarcoma, 

Lymph node, mandibular 

metastatic, uterus 

Histiocytic sarcoma, metastatic, 

Histiocytic sarcoma 

Lumbar, sarcoma, metastatic, skin X 

uterus 

Histiocytic sarcoma, metastatic, 

Histiocytic sarcoma 

Lymph node, mesenteric 

uterus 

Spleen 

Histiocytic sarcoma 

Hemangiosarcoma 

Hemangioma X 

Thymus 

Histiocytic sarcoma, metastatic, 

Histiocytic sarcoma 

metastatic, lung 

Abeolar/bronchiolar carcinoma, 

uterus 

1 

1 

1 

Mammary gland 

Integumentary System 

......................... 50 

X 1 

1 

++++M++++++++++++++M+++++ 46 

Adenoma 

Adenocarcinoma 

Skin 

Sarcoma 

Hemangiosarcoma 

X 1 

1 
210 Methylphenidate Hydrochloride, NTP TR 439 

(continued) 

Individual Animal Tumor Pathology of Female Mice in the 2-Year Feed Study of Methylphenidate Hydrochloride: 250 ppm 

TABLE D2 

7398766975898222222222222 

5867058890012444444444444 

0145666667777777777777777 

1925928806778359234561383 

5586665447436444555556678 

4444444444444444444444444 

Number of Days on Study 

Carcass ID Number 

Musculoskeletal System 

Bone 

X 

......................... Alveolaribronchiolar carcinoma, 

metastatic, lung 

Nervous System 

Brain ......................... 

'Respiratory System 

Lung 

Alveolaribionchiolar carcinoma, 

Alveolaribronchiolar carcinoma 

Alveolaribronchiolar adenoma 

Carcinoma, metastatic, thyroid gland 

Histiocytic sarcoma, metastatic, 

Sarcoma, metastatic, skin 

Histiocytic sarcoma, metastatic, 

metastatic, lung 

uterus 

NoSe 

uterus 

Trachea 

X 

X ......................... X 

X 

X 

......................... 

X 

.......................... 

Harderian gland 

Ear 

special se- system 

Adenoma X 

+ 

X +' + 

Urinary bladder 

KidnG 

Urinary System 

A+++AA+++A+A+++M+++++++++ 

.......................... 

Systemic Lesions .. 

Multiple organs ......................... 

Lymphoma malignant mixed 

Lymphoma malignant lymphocytic 

Histiocytic sarcoma xx 

X 

X 
Lesions in Female Mice 211 

(continued) 

Individual Animal Tumor Pathology of Female Mice in the 2-Year Feed Study of Methylphenidate Hydrochloride: 250 ppm 

TABLE D2 

2222222222233333333333333 

4444444444444444444444444 

1111111111111111111711111 

Number of Days on Study 

Carcass ID Number 

4444444445544444444444455 Total 

8888999990033345561719900 Tipsuest 

4519011894568940170354612 Tumors 

Musculoskeletal System 

Bone 

Alveolar/bronchiolar carcinoma, 

metastatic, lung 1 

......................... 50 

Nervous System 

Brain ......................... 50 

Respiratory System 

Alveolarbronchiolar carcinoma, 

' Alveolarbronchiolar carcinoma 

Alveolarbronchiolar adenoma 

Lung 

Carcinoma, metastatic, thyroid gland 

Histiocytic sarcoma, metastatic, 

Sarcoma, metastatic, skin 

Histiocytic sarcoma, metastatic, 

2 

X 4 

......................... 50 

1 

1 

......................... 50 

1 

1 

......................... 50 

1 

X 

X 

metistatic, lung 

X 

uterus 

X 

NO.% 

uterus 

Trachea 

Harderian gland 

Ear 

Special Senses System 

3 

4 

++ 2 

X 

+ 

Adenoma 

Urinaty bladder 

Kidney 

Urinary System 

......................... 50 

......................... 44 

Systemic Lesions 

Multiple organs 

6 

2 

2 

......................... 50 

Lymphoma malignant mixed 

Lymphoma malignant lymphocytic 

Histiocytic sarcbma 

X 

X X xx X 
212 Methylphenidate Hydrochloride, NTP TR 439 

Individual Animal Tumor Pathology of Female Mice in the 2-Year Feed Study of Methylphenidate Hydrochloride: 500 ppm 

TABLX D2 

80070591111111111111lllll 

4667993444444444444444444 

6666667777777777777777777 

5555555555555555555555555 

Number of Days on Study 

Carcass ID Number 

9701913680256702478035901 

2561327012222233333444455 

Esophagus 

Alimentary System 

......................... 

Liier 

Intestine small, ileum 

Intestine small, jejunum 

Intestine small, duodenum 

Intestine large, cecum 

Intestine large, rectum 

Intestine large, colon 

Gallbladder 

......................... 

......................... 

......................... 

......................... 

++++M++++++++++++++++++++ 

x xx X .x xx 

X 

......................... 

......................... 

......................... 

Hepatocellular adenoma, multiple 

Hepatocellular adenoma 

Hepatocellular carcinoma, multiple 

Hepatocellular carcinoma X 

X xx X X' x 

Pancreas 

Mesentery + ......................... 

Tongue 

Stomach, glandular 

Stomach, forestomach 

Salivary glands 

......................... 

.......................... 

.......................... 

+ 

Cardiovascular System 

HIXrt 

.. 

......................... 

Adrenal cortex 

Endocrine System 

......................... 

Islets, pancreatic 

Pheochromocytoma benign 

Adrenal medulla 

Capsule, adenoma 

Adenocarcinoma, metastatic, uterus 

Pituitary gland 

Parathyroid gland 

Adenoma 

Follicular cell, adenoma 

Pars intermedia, adenoma 

Pars distalis, adenoma 

Thyroid gland 

X 

......................... X 

......................... 

+++++++++++++++++++M+++++ 

xx 

+++M++++++++++M+++++++++M 

+M+++M++M+M++++++MMM+++++ 

X 

X 

X 

X X 

General Body System 

ovav 

Genital System 

None 

Clitoral gland 

+++++M+++++++++++++++++++ 

+++M++++++++++++++++++M++ 

Cystadenoma 

Endometrium, adenocarcinoma 

Polyp stromal 

Histiocytic sarcoma 

X 

Uterus .......................... 

x 

X 
Lesions in Female Mice 213 

(continued) 

Individual Animal Tumor Pathology of Female Mice in the 2-Year Feed Study of Methylphenidate Hydrochloride: 500 ppm 

TABLE D2 

Number of Days on Study 

1111111111111112222222222 

4444444444444444444444444 

1111111111111111111111111 

Carcass ID Number 

5555555555555555555555555 Total 

5555566666661170011111366 Tissues/ 

3568913456180121834561529 Tumors 

Liver 

Intestine small, ileum 

Intestine small, jejunum 

Intestine small, duodenum 

Intestine large, cecum 

Intestine large, rectum 

Intestine large, colon 

Gallbladder 

Esophagus 

Alimentary System 

~ ~~~ ~~~ ~ 

Hepatocellular adenoma, multiple 

Hepatocellular adenoma 

Hepatocellular carcinoma, multiple 

Hepatocellular carcinoma 

Tongue 

Stomach, glandular 

Stomach, forestomach 

Salivary glands 

Pancreas 

Mesentery 

......................... 50 

++++++++++++++++++++++++M 48 

......................... 50 

......................... 50 

......................... 50 

......................... 50 

......................... 50 

++++++++++++++++++++M++++ 49 

1 

......................... 50 

......................... 50 

+++++++M+++++++++++++++++ 49 

......................... 50 

2 

x xx x x xx 15 

’ 13 

1 

X 5 

. ......................... 50 

X 

X X 

X X 

x x .x x X 

X 

+ 

Cardiovascular System 

Heart ......................... 50 

Adrenal cortex 

Endocrine System 

1 

1 

......................... 50 

......................... 50 

1 

.......................... 50 

Pheochromocytoma benign 

Capsule, adenoma 

Adenocarcinoma, metastatic, uterus 

X 

Islets, pancreatic 

Adrenal medulla 

Pituitary gland 

Parathyroid gland 

Adenoma 

Follicular cell, adenoma 

Pars intermedia, adenoma 

Pars distalis, adenoma 

Thyroid gland 

......................... 41 

+MM+M+++++++++++++++++MM+ 38 

1 

X X X xx 8 

1 

4 

......................... 49 

X X 

General Body System 

None 

Ovary 

Clitoral gland 

Genital System 

Uterus 

Cystadenoma 

Endometrium, adenocarcinoma 

Polyp stromal 

Histiocytic sarmrna 

1 

1 

1 

......................... 50 

1 

+++M+++++++++++++++++++++ 48 

........................ 46 

X 
214 Methylphenidate Hydrochloride, NTP TR 439 

Number of Days on Study 

8007059111111111111111111 

4667993444444444444444444 

6666667777777777777777777 

Carcass ID Number 

9701913680256702478035901 

258132701222223333344-4455 

555555-5555555555555555555 

Hematopoietic System 

Lymph node, mandibular 

Lymph node 

Bone marrow 

......................... 

Adenocarcinoma, metastatic, uterus X 

......................... 

+ + + + 

Carcinoma, metastatic, harderian 

gland X 

Spleen 

Lymph node, mesenteric 

+++M+++++++++++++++++++++ 

......................... 

+++++M+++++++++++++++++++ 

Adenocarcinoma, metastatic, uterus X 

Thymus 

Skin 

Mammary gland 

Integumentary System 

Adenocarcinoma, metastatic, uterus X 

++M++++++M+++++++++M+++++ 

Sarcoma 

Histiocytic sarcoma X ......................... 

X 

Musculoskeletal System 

Bone ......................... 

Nervous System 

Brain 

Adenocarcinoma, metastatic, uterus X 

......................... 

Respiratory System 

Lung 

Carcinoma, metastatic, harderian 

Alveolaribronchiolar carcinoma 

Alveolaribronchiolar adenoma 

Adenocarcinoma, metastatic, uterus 

Hepatocellular carcinoma, metastatic, 

liver 

gland 

Nose 

Carcinoma, metastatic, harderian 

Trachea 

gland 

......................... 

X 

X 

X 

X X 

X 

X 

......................... 

X ......................... 

Special Senses System 

Carcinoma 

Adenoma 

Harderian gland 

X 

+ + 

X 

Hemangioma 

Urinary bladder ......................... Adenocarcinoma, metastatic, uterus X 

Kidney ......................... Urinary System 
Lesions in Female Mice 215 

(continued) 

Individual Animal Tumor Pathology of Female Mice in the 2-Year Feed Study of Methylphenidate Hydrochloride: 500 ppm 

TABLE D2 

7777777777777777777777777 

Number of Days on Study 

1111111111111112222222222 

4444444444444444444444444 

Carcass ID Number 

5555555555555555555555555 Total 

5555566666667770011111366 Tissues/ 

3568913456780127834567529 Tumors 

Hematopoietic System 

Lymph node, mandibular 

Lymph node 

Bone marrow 

Adenocarcinoma, metastatic, uterus 

Carcinoma, metastatic, harderian 

gland 

Spleen 

Lymph node, mesenteric 

Thymus 

Adenocarcinoma, metastatic, uterus 

+++++++M+++++++++++++++++ 49 

5 

1 

......................... 50 

+ 

......................... 50 

++M++++++++M+++++++++++++ 47 

1 

1 

.......................... 49 

Skin 

Mammary gland 

Integumentary System 

1 

1 

......................... 50 

1 

++++++MM+++++++++++++M+++ 44 

Sarcoma 

Histiocytic sarcoma 

Adenocarcinoma, metastatic, uterus 

Musculoskeletal System 

Bone ......................... 50 

Nervous System 

Brain 

1 

......................... 50 

Adenocarcinoma, metastatic, uterus 

Respiratory System 

Lung 

2 

X 6 

1 

......................... 50 

......................... 50 

1 

......................... 50 

X 1 

1 

Carcinoma, metastatic, harderian 

Alveolarbronchiolar carcinoma 

Ahreolar/bronchiolar adenoma 

Adenocarcinoma, metastatic, uterus 

Hepatocellular carcinoma, metastatic, 

X X 

her 

gland 

Nose 

Carcinoma, metastatic, harderian 

Trachea 

gland 

Special Senses System 

Carcinoma 

Adenoma 

Harderian gland 

X 

+ + 

X 3 

1 

+ 5 

Hemangioma 

Urinary bladder 

Adenocarcinoma, metastatic, uterus 

Kidney 

Urinary System 

1 

......................... 50 

1 

......................... 50 

X 
216 Methylphenidate Hydrochloride, NTP TR 439 

TABLE D2 

(continued) 

Individual Animal Tumor Pathology of Female Mice in the 2-Year Feed study of Methylphenidate Hydrochloride: 500 ppm 

8007059111111111111111111 

4667993444444444444444444 

6666667777777777777777777 

9701913680256702478035901 

2561327012222233333444455 

5555555555555555555555555 

Number of Days on Study 

Carcass ID Number 

Systemic Lesions 

Multiple organs 

Histiocytic sarcoma X ......................... 

Lymphoma malignant mixed 

Lymphoma malignant lymphocytic 

X xx X xx X 
Lesions in Female Mice 217 

(continued) 

Individual Animal Tumor Pathology ofFemale Mice in the 2-Year Feed Study of Methylphenidate Hydrochloride: 500 ppm 

TABLE D2 

1111111111111112222222'222 

4444444444444444444444444 

1111111111111111111111111 

5555555555555555555555555 Total 

5555566666667170011111366 TiSSUeS/ 

3568913456180127834561529 Tumors 

Number of Days on Study 

Carcass ID Number 

Multiple organs 

Systemic Lesions 

14 

3 

2 

......................... 50 

Lymphoma malignant mixed 

Lymphoma malignant lymphocytic 

Histiocytic sarcoma 

xxx X xx x 

X 

X X X 
218 Methylphenidate Hydrochloride, NTP TR 439 

Statistical Analysis of Primary Neoplasms in Female Mice in the 2-Year Feed Study of Methylphenidate Hydrochloride 

TABLE D3 

250 ppm 

Fisher exact test 

Cochran-Armita e testd 

Logistic regression testsd 

Life table tests 

First incidence days 

Terminal rates' 

Adjusted ratesb 

Overall ratesa 

Harderian Gland Adenoma 

Fwher exact test 

Cochran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

Harderian Gland Carcinoma 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

Harderian Gland Adenoma or Carcinoma 

Fisher exact test 

Cochran-Armitage test 

Logistic regression tests 

, Life table tests 

Fisher exact test 

Cochran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

Uver: Hepatocellular Adenoma 

Fisher exact test 

Cochran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

Liver: Hepatocellular Carcinoma 

I 

d) 

1/37 (3%) 

2.7% 

1/49 (2%) 

P=O.395 

P=O.439 

P=O.455 

739 0 

0/37 (0%) 

0.0% 

0149 (0%) 

P=O.O57 

P=O.o65 

P =0.079 

- 

1/37 (3%) 

2.7% 

1/49 (2%) 

P=O.o68 

P=O.o88 

P=O.107 

739 0 

6/37 (16%) 

16.2% 

6/49 (12%) 

PCO.001 

PCO.001 

PCO.001 

739 (T,) 

5/37 (14%) 

13.5% 

5/49 (10%) 

P~O.352 

P50.430 

PEO.460 

739 (TI 

e 

0.0% 

0/49 (0%) 

OB5 (0%) - 

P=O.SOON 

P=O.511N 

P=0.511N 

2.9% 

1/49 (2%) 

739 (T) 

1/35 (3%) 

P=O.500 

P=O.489 

P=O.489 

2.9% 

1/49 (2%) 

739 (T) 

1/35 (3%) 

.P=O.753N 

P=O.749 

P=O.749 

P=O.164 

P=O.174 

588 

8/35 (23%) 

26.6% 

10/48 (21%) 

P=O.194 

P =0.383N 

P=0.386N 

730 

2/35 (6%) 

8.3% 

3/48 (6%) 

P=0.369N 

7.8% 

3/50 (6%) 

P~O.313 

P=O.307 

708 

P~O.316 

2/37 (5%) 

Of37 (0%) 

0.0% 

0/50 (0%) 

- 

- 

- 

- 

7.8% 

3/50 (6%) 

P=O.313 

P=O.307 

708 

P20.316 

2/37 (5%) 

26.1% 

10/49 (20%) 

P = 0.220 

P=O.207 

689 

P=O.rn 

9/37 (24%) 

P=0.215N 

P=0.215N 

739 (T) 

2/37 (5%) 

5.4% 

2/49 (4%) 

P=0.218N 

1/50 (2%) 

P=0.747N 

P=0.723N 

P=0.723N 

1/44 (2%) 

2.3% 

739 0 

6.6% 

3/50 (6%) 

P50.122 

P=O.152 

677 

P=O.125 

2/44 (5%) 

8.8% 

4/50 (8%) 

P=O.uH) 

P=O.233 

677 

P=O.187 

3/44 (7%) 

P < 0.001 

P<O.001 

690 

27/44 (61%) 

62.2% 

23/50 (56%) 

PCO.001 

13.2% 

6/50 (12%) 

P=O.575 

P=O.617 

660 

P-0.514 

5/44 (11%) 
Lesions in Female Mice 219 

(continued) 

Statistical Analysis of Primary Neoplasms in Female Mice in the 2-Year Feed Study of Methylphenidate Hydrochloride 

TABLE D3 

Fisher exact test 

Cocbn-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

Liver: Hepatocellular Adenoma or Carcinoma 

Fisher exact test 

Cochran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

Lung: Alveolar/bronchiolar Adenoma 

Fisher exact test 

Cochran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

overall rates 

Lung: Alveolar/bronchiolar Adenoma or Carcinoma 

Fisher exact test 

Cochran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

overall rates 

Ovary: Cystadenoma 

Fisher exact test 

Cochran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

Pituitary Gland (Pars Distalis): Adenoma 

24.3% 

9/49 (18%) 

739 0 

9/37 (24%) 

P<O.ool 

P<O.ool 

P<O.ool 

1/36 (3%) 

2.8% 

1/48 (2%) 

P=O.O12 

P=O.O21 

P=O.O26 

739 0 

2.8% 

1/48 (2%) 

739 (T) 

1/36 (3%) 

P=O.O05 

P=O.OlO 

P=O.O13 

1/35 (3%) 

2.9% 

1/46 (2%) 

P=0.182N 

P=0.207N 

P=0.153N 

739 (T) 

P=O.436 

P=0.508N 

P=0.454N 

708 

6/37 (16%) 

18.3% 

7/48 (15%) 

P=O.335 

P=O.351 

588 

8/35 (23%) 

2.8.7% 

11/48 (23%) 

P=O.381 

2.9% 

1/49 (2%) 

739 Q 

1/35 (3%) 

P=0.747N 

P=O.756 

P=O.756 

1/35 (3%) 

2.9% 

1/49 (2%) 

P=O.756 

P=O.756 

739 (T) 

P=0.747N 

P=O.122 

P=O.104 

391 

2/35 (6%) 

12.3% 

5/48 (10%) 

P=O.112 

1OB4 (29%) 

29.4% 

10/48 (21%) 

P=O.297 

P=O.234 

P=O.229 

739 (T) 

P=O.427 

P-0.403 

689 

10/37 (27%) 

28.7% 

11/49 (22%) 

P=O.401 

10.8% 

4/50 (8%) 

739 (T) 

4/37 (11%) 

P=O.187 

P=O.187 

P=O.194 

P=O.O65 

P=O.o64 

728 

5/37 (14%) 

15.8% 

6/50 (12%) 

P=O.O62 

1/37 (3%) 

2.7% 

1/49 (2%) 

P =0.749N 

P=0.749N 

739 (T) 

P=0.737N 

P=O.O47 

P=O.O45 

686 

12/36 (33%) 

37.9% 

15/49 (31%) 

P=O.O50 

P<O.ool 

P < 0.001 

660 

28/44 (64%) 

65.2% 

30/50 (60%) 

P <0.001 

13.3% 

6/50 (12%) 

P=O.O81 

P=O.O97 

690 

P=O.o62 

5/44 (11%) 

P=O.O49 

P=O.O60 

690 

6/44 (14%) 

15.5% 

7/50 (14%) 

P=O.O34 

P=0.766N 

P=0.725N 

677 

0/43 (0%) 

2.1% 

1/48 (2%) 

P=O.742N 

P=O.563 

P=O.603 

690 

7/42 (17%) 

18.5% 

8/47 (17%) 

P=O.482 
220 Methylphenidate Hydrochloride, NTP TR 439 

(continued) 

Statistical Analysis of Primary Neoplasms in Female Mice in the 2-Year Feed Study of Methylphenidate Hydrochloride 

TABLE D3 

Fisher exact test 

Cochran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

Thyroid Gland (Follicular Cell): Adenoma 

Fisher exact test 

Cochran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

Thyroid Gland (Follicular Cell): Adenoma or Carcinoma 

Fisher exact test 

Cochran-Annitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

Uterus: Stromal Polyp 

Fisher exact test 

Cochran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

All Organs: Hemangioma 

Fisher exact test 

Cochran-Annitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

All Organs: Hemangiosarcoma 

OB7 (0%) 

0.0% 

0/49 (0%) 

P=O.391 

P=O.450 

P=O.475 

- 

OB7 (0%) 

0.0% 

0/49 (0%) 

P=O.367 

P=O.429 

P=O.454 

- 

P=O.459 

P=O.517 

P=O.538 

708 

1/37 (3%) 

5.1% 

2/49 (4%) 

2/37 (5%) 

5.4% 

2/49 (4%) 

P=O.571 

P=0.603N 

P=0.567N 

739 Q 

P=O.13ON 

P=0.125N 

P=0.107N 

685 

2/37 (5%) 

7.7% 

3/49 (6%) 

6/35 (17%) 

17.1% 

6/48 (13%) 

P10.012 

P=O.O14 

P=O.O14 

739 (T) 

6/35 (17%) 

17.1% 

6/48 (13%) 

P=O.O12 

P~O.014 

P=O.O14 

739 0 

On5 (0%) 

0.0% 

0/49 (0%) 

P=0.247N 

P=O.248N 

P=O.258N 

- 

OB5 (0%) 

0.0% 

0/49 (0%) 

P=0.247N 

P=0.251N 

P=0.251N 

- 

P=O.306N 

P=0.326N 

603 

OB5 (0%) 

2.3% 

1/49 (2%) 

P=0.309N 

OB7 (0%) 

0.0% 

0149 (0%) 

- 

- 

- 

- 

1/37 (3%) 

2.7% 

1/49 (2%) 

P=O.500 

P=O.500 

P=O.500 

739 (T) 

P=O.141 

P=O.139 

705 

5/37 (14%) 

15.6% 

6/50 (12%) 

P=O.141 

7.5% 

3/50 (6%) 

P=O.508 

P=O.504 

656 

P-0.510 

2/37 (5%) 

5.4% 

2/50 (4%) 

739 (T) 

2/37 (5%) 

P=0.49ON 

P = 0.49ON 

P=0.494N 

P=O.o66 

P=O.o84 

677 

3/43 (7%) 

9.0% 

4/49 (8%) 

P=O.O59 

P=O.o66 

P-0.084 

677 

3/43 (7%) 

9.0% 

4/49 (8%) 

P=O.O59 

2.3% 

1/50 (2%) 

739 0 

1/44 (2%) 

P-0.492N 

P=O.47ON 

P =0.449N 

2.3% 

1/50 (2%) 

739 0 

1/44 (2%) 

P~0.492N 

P=0.44ON 

P=O.44ON 

0.0% 

0/50 (0%) 

ow (0%) - 

P=0.117N 

P=O.llON 

P-0.097N 
Lesions in Female Mice 221 

(continued) 

Statistical Analysis of Primary Neoplasms in Female Mice in the 2-Year Feed Study of Methylphenidate Hydrochloride 

TABLE D3 

0 PPm 50 PPm 250 ppm 500 ppm 

Fisher exact test 

Cochran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

All Organs: Hemangioma or Hemangiosarcoma 

Fisher exact test 

Cochran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

All Organs: Malignant Lymphoma (Lymphocytic 

Fisher exact test 

Cochran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

All Organs: Benign Neoplasms 

Fisher exact test 

Cochran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

All Organs: Malignant Neoplasms 

Fisher exact test 

Cochran-Armitage test 

Logistic regression tests 

Life table tests 

First incidence (days) 

Terminal rates 

Adjusted rates 

Overall rates 

All Organs: Benign or Malignant Neoplasms 

P=0.321N 

P=0.301N 

P=0.254N 

685 

3/37 (8%) 

10.3% 

4/49 (8%) 

or Mixed) 

P=O.218 

P=O.272 

P=O.410 

621 

8/37 (22%) 

28.9% 

12/49 (24%) 

P=O.OOl 

P=O.O07 

P=O.O32 

708 

17/37 (46%) 

48.6% 

19/49 (39%) 

P=O.286 

P=O.343 

P=0.484N 

621 

17/37 (46%) 

52.2% 

22/49 (45%) 

P=O.O74 

P=O.126 

P=0.505N 

571 

27/37 (73%) 

77.2% 

34/49 (69%) 

2.3% 

1/49 (2%) 

P=0.184N 

P=0.200N 

603 

P=0.181N 

on5 (0%) 

P=O.445 

P=O.436 

625 

10/35 (29%) 

33.8% 

13/49 (27%) 

P=O.500 

P=O.102 

P=O.107 

391 

20/35 (57%) 

62.1% 

25/49 (51%) 

P=O.155 

50.8% 

21/49 (43%) 

P=0.576N 

P=O.558 

462 

15/35 (43%) 

P=0.500N 

P=O.340 

P=O.308 

103 

24/35 (69%) 

76.6% 

36/49 (73%) 

P=O.412 

4/37 (11%) 

5/50 (10%) 

12.8% 

P=O.511 

P=O.508 

656 

P=O.513 

P=0.211N 

P=O.232N 

183 

6/37 (16%) 

20.0% 

8/50 (16%) 

P=O.212N 

P=O.O23 

P=O.O25 

656 

25/37 (68%) 

71.2% 

30/50 (60%) 

P=O.O28 

P=0.134N 

P=0.167N 

183 

10/37 (27%) 

36.5% 

16/50 (32%) 

P=0.133N 

P=O.145 

PfO.193 

183 

30/37 (81%) 

85.0% 

40/50 (80%) 

P=O.163 

1/50 (2%) 

P=0.175N 

P=0.154N 

P=0.137N 

1/44 (2%) 

2.3% 

739 (T) 

P=O.272 

P=O.361 

690 

16/44 (36%) 

37.7% 

17/50 (34%) 

P=O.207 

P=O.O06 

P=O.O17 

660 

32/44 (73%) 

74.4% 

35/50 (70%) 

P=O.002 

P=O.403 

P=O.565 

648 

22/44 (50%) 

54.0% 

26/50 (52%) 

P=O.307 

85.4% 

41/50 (82%) 

P=O.242 

P=O.510 

648 

P=O.109 

37/44 (84%) 
222 Methylphenidate Hydrochlorlac, NTP TR 439 

(continued) 

Statistical Analysis of Primary Neoplasms in Female Mice in the 2-Year Feed Study of Methylphenidate Hydrochloride 

TABLE D3 

OTerminal sacrifice 

exact tests compare directly the overall incidence rates. For all tests, a negative trend or a lower incidence in an exposure group is indicated by N. 

as being (directly or indirectly) the cause of death. The logistic regression test regards these lesions as nonfatal. The cochran-Armitage and Fisher 

to pailwise comparisons between the controls and that exposed group. The life table test regards neoplasms in animals dying prior to terminal kill 

Beneath the control incidence are the P values associated with the trend test. Beneath the exposed group incidence are the P valuar corresponding 

Observed incidence at terminal kill 

Kaplan-Meier estimated neoplasm incidence at the end of the study after adjustment for intercurrent mortality 

ovary, pituitary gland, thyroid gland, and uterus; for other tissues, denominator is number of animals necropied. 

Number of neoplasm-bearing animaWnumber of animals examined. Denominator is number of animals examined microscopically for li, lung, 

e Not applicable; no neoplasms in animal group 
Lesions in Female Mice 223 

Historical Incidence of Liver Neoplasms in Untreated Female B6C3Fl MiceP 

TABLE D4 

Study 

Adenoma Carcinoma Adenoma or Carcinoma 

Hepatocellular Hepatocellular Hepatocellular 

Incidence in Controls 

Historical Incidence at TSI Mason Research Institute 

Tumeric oleoresin 

Pentaerythritol tetranitrate 

H.C. Yellow 4 

Acetaminophen 

l-Amino-2,4dibromoanthraquinone 

Overall Historical Incidence 

Range 

Standard deviation 

Total 

7/50 

5/49 

5/50 

3/49 

6/50 

7/50 

1/49 

1/50 

0/49 

0150 

159/1,363 (11.7%) m/1,363 (5.9%) 

8.3% 

0%-20% 

5.5% 

0%-33% 

13/50 

6/49 

6/50 

3/49 

6/50 

3%-42% 

10.7% 

223/l,363 (16.4%) 

Data as of 20 August 1992 
224 Methylphenidate Hydrochloride, NTP TR 439 

of Methylphenidate Hydrochloridea 

Summary of the Incidence of Nonneoplastic Lesions in Female Mice in the 2-Year Feed Study '. 

TABLE D5 

0 PPm 50 PPm 250 ppm 500 ppm 

Early deaths 

ISMonth interim evohrmion 

%Month intaim evohrmion 

Animals initially in study 

Disposition Summary 

Natural deaths 

Moribund 

Accidental deaths 

Terminal sacrifice 

Died last week of study 

Survivors 

Missing 

10 

10 

69 

5 

6 

1 

36 

1 

10 

9 

69 

7 

7 

1 

34 

1 

10 

10 

70 

6 

7 

37 

10 

10 

70 

6 

44 

Animals examined microscopically 69 68 70 70 

PMonth Interim Evaluation ., 

Alimentary System 

Fatty change 

Eosinophilic focus 

Liver 

Diverticulum 

Inflammation, chronic, focal 

Inflammation, chronic, focal 

Stomach, forestomach 

Salivary glands 

Pancreas 

None 

Cardiovascular System 

Hypoplasia 

Hyperplasia 

Islets, pancreatic 

Endocrine System 

None 

General Body System 

Clitoral gland 

Genital System 

(10) 

(1) 

Uterus 

cyst 

Cyst 1 (100%) 

Ovary (9) (10) (9) 

9 (90%) 

1 (11%) 1 (10%) 

2 (22%) 

Endometrium, hyperplasia, cystic 

Mineralization, focal 

(10) (9) (10) (10) 

9 (90%) 8 (89%) 9 (90%) 

~ ~ ~~ ~ ~ ~~~ ~~~ ~ ~ ~ 

a Number of animals examined microscopically at site and number of animals with lesion 
Lesions in Female Mice 225 

of Methylphenidate Hydrochloride (continued) 

Summary of the Incidence of Nonneoplastic Lesions in Female Mice in the 2-Year Feed Study 

TABLE D5 

Lymph node, mandibular 

Hematopoietic System 

9-Month Interim Evaluation (continued) 

Spleen (10) 

(10) 

Hematopoietic cell proliferation 

Congestion 

None 

Integumentary System 

None 

Musculoskeletal System 

Brain 

Nervous System 

Mineralization, focal 

Nose 

Lung 

Respiratory System 

(10) 

(10) 

(9) 

(9) 

(10) 

(10) 

(10) 

(10) 

Inflammation, chronic, focal 

Degeneration, hyaline 

Peribronchial, inflammation, chronic 

10 (100%) 8 (89%) 10 (100%) 10 (100%) 

4 (44%) 8 (80%) 

3 (30%) 1 (11%) 

7 (70%) 

5 (50%) 

8 (80%) 

None 

Special Senses System 

Kidney 

Urinary System 

Inflammation, chronic, focal 

Renal tubule, regeneration 

Inflammation, chronic, focal 

Urinary bladder 

15-Month Interim Evaluation 

Alimentary System 

Necrosis, focal 

Fatty change 

Eosinophilic focus 

Basophilic focus 

Liver 

Inflammation, chronic, focal 

Pancreas 

2 (20%) 

(10) 

(10) (10) (10) 

3 (30%) 2 (20%) 

2 (20%) 1 (10%) 

1 (10%) 

2 (20%) 1 (10%) 

4 (40%) 3 (30%) 3 (30%) 

(10) (10) (101 
226 Methylphenidate Hydrochloride, NTP TR 439 

of Methylphenidate Hydrochloride (continued) 

Summary of the Incidence of Nonneoplastic Lesions in Female Mice in the 2-Year Feed Study 

TABLE D5 

Salivary glands 

Alimentary System (continued) 

15-Month Interim Evaluation (continued) 

Inflammation, chronic, focal , 

Stomach, glandular 

Inflammation, chronic, focal 

(10) 

(10) 

(10) 

(10) 

(10) 

(10) 

(10) 

(10) 

4 (40%) 4 (40%) 

1 (10%) 

5 (50%) 5 (50%) 

None 

Cardiovascular System 

Hyperplasia 

Islets, pancreatic 

Endocrine System 

Pars distalis, hyperplasia, focal 

Pituitary gland 

None 

General Body System 

Ovary 

Genital System 

(9) (10) (10) ' 

(10) 

(10) 

Cyst 1 (11%) 

10 (100%) 10 (100%) 9 (90%) 

2 (20%) 1 (10%) 

1 (10%) 

2 (20%) 2 (20%) 

8 (80%) 

3 (30%) 

1 (10%) 

Endometrium, hyperplasia, cystic 

Hydrometra 

Thrombosis 

Uterus (10) (10) (10) 

Spleen 

Bone marrow 

Hematopoietic System 

(9) 

(10) 

(10) 

(10) 

(10) 

(10) 

(9) 

(10) 

(10) 

(10) 

(10) 

(10) 

Hyperplasia, lymphoid 

Hematopoietic cell proliferation 

Myelofibrosis 3 (30%) 

1 (10%) 

1 (10%) 1 (10%) 1 (10%) 

Thymus 

1 (11%) 

None 

Integumentary Syste-m 

None 

Musculoskeletal System 

Mineralization 

Brain 

Nervous System 

(10) (10) (10) (10) 

6 (60%) 5 (50%) 6 (60%) 6 (60%) 
Lesions in Female Mice 227 

of Methylphenidate Hydrochloride (continued) 

Summary of the Incidence of Nonneoplastic Lesions in Female Mice in the 2-Year Feed Study 

TABLE D5 

0 PPm 50 PPm 250 ppm 500 ppm 

NOSe 

Respiratory System 

15-Month Interim Evaluation (continued) 

(10) (10) (10) (10) 

Inflammation, chronic 8 (80%) 8 (80%) 7 (70%) 9 (90%) 

None 

Special Senses System 

~ ______ ~~~~ ____ ~~ ~ 

Urinary bladder 

Urinary System 

(10) (10) (10) 

Inflammation, chronic, focal 4 (40%) 5 (50%) 4 (40%) 

2-Year Study 

Intestine large, cecum 

Gallbladder 

Alimentary System 

(47) 

(44) 

(44) 

(40) 

(45) 

(43) 

Edema 

Dilatation 

Angiectasis 

Hyperplasia, lymphoid 

Hyperplasia, lymphoid 

Necrosis, focal 

Hyperplasia, lymphoid 

Hemorrhage 

Hematopoietic cell proliferation 

Fatty change, focal 

Fatty change 

Eosinophilic focus 

Congestion 

Clear cell focus 

Basophilic focus 

Autolysis 

Duct, ectasia 

Acinus, atrophy 

Fat, necrosis 

Ulcer 

Diverticulum 

Abscess 

Stomach, forestomach 

Muscularis, hypertrophy 

Inflammation, subacute 

Inflammation, chronic 

Erosion 

Edema 

Stomach, glandular 

Angiectasis 

1 (3%j 

1 (2%) 

2 (4%) 

1 (2%) 

1 (2%) 

2 (4%) 

30 (64%) 18 (41%) 18 (40%) 

Liver 

Intestine small, jejunum 

(49) 

(45) 

(48) 

(44) 

(49) 

(45) 

2 (4%) 

1 (2%) 

1 (2%) 

1 (2%) 

1 (2%) 

1 (2%) 

5 (83%) 

5 (10%) 

2 (4%) 

2 (4%) 

4 (8%) 

1 (2%) 

3 (6%) 3 (6%) 8 (16%) 

1 (2%) 

1 (2%) 

1 (2%) 

1 (2%) 2 (4%) 

2 (4%) 

4 (8%) 

4 (8%) 

Pancreas 

Mesentery 

(48) 

(6) 

(49) 

(1) 

(48) 

1 (2%) 

1 (2%) 1 (2%) 

1 (2%) 

1 (2%) 

2 (4%) 

(47) (49) (49) 

1 (2%) 

1 (2%) 

(48) (46) (48) 

1 (2%) 

2 (4%) 

1 (2%) 

1 (2%) 

1 (2%) 

3 (1W) 

1 (2%) 

Tongue (3) 

1 (2%) 

2 (4%) 

25 (50%) 

2 (100%) 

(2) 

10 (20%) 

2 (4%) 

2 (4%) 

(50) 

(50) 
228 Methylphenidate Hydrochloride, NTP TR 439 

of Methylphenidate Hydrochloride (continued) 

Summary of the Incidence of Nonneoplastic Lesions in Female Mice in the 2-Year Feed Study 

TABLE D5 

Heart 

Cardiovascular System 

ZYear Study (continued) 

Artery, inflammation, chronic 

Congestion 

Adrenal cortex 

Endocrine System 

Hyperplasia, focal 

Hematopoietic cell proliferation 

Fibrosis 

Cytoplasmic alteration, focal 

Hyperplasia, focal 

Adrenal medulla 

Capsule, hyperplasia 

Pituitary gland 

Hyperplasia 

Islets, pancreatic 

Pars distalis, hyperplasia, focal 

Pars distalis, angiectasis 

Follicular cell, hyperplasia, focal 

Follicle, cyst 

Inflammation, chronic 

Inflammation, acute, focal 

Hypertrophy 

Thyroid gland 

4 (8%) 

(49) 

13 (27%) 

(49) 

None 

General Body System 
Lesions in Female Mice 229 

of Methylphenidate Hydrochloride (continued) 

Summary of the Incidence of Nonneoplastic Lesions in Female Mice in the 2-Year Feed Study 

TABLE DJ 

0 PPm 50 PPm 250 ppm 500 ppm 

Hematopoietic- System 

Myelofibrosis 

Hyperplasia, neutrophil 

Angiectasis 

Bone marrow 

Mediastinal, infiltration cellular, mixed 

Mediastinal, hyperplasia, lymphoid 

Lumbar, lymphatic, angiectasis 

Lumbar, hematopoietic cell proliferation 

Renal, hematopoietic cell proliferation 

Pancreatic, hyperplasia, lymphoid 

Lymphatic, angiectasis 

Necrosis 

Hematopoietic cell proliferation 

Lymphatic, angiectasis 

Inflammation, chronic 

Depletion lymphoid 

Congestion 

Lymph node, mesenteric 

Necrosis, focal 

Hyperplasia, lymphoid 

Hematopoietic cell proliferation 

Depletion lymphoid 

Congestion 

Hyperplasia, lymphoid 

Depletion lymphoid 

Angiectasis 

Lymph node 

cell 

Lymph node, mandibular 

Spleen 

Thymus 

Lactation 

Mammary gland 

Integumentary System 

Ulcer 

Inflammation, chronic 

Skin 

(49) 

(7) 

22 (45%) 

2 (4%) 

1 (14%) 

1 (14%) 

1 (14%) 

1 (14%) 

(48) 

1 (2%) 

(45) 

.1 (2%) 

1 (2%) 

1 (2%) 

(48) 

2 (4%) 

1 (2%) 

1 (2%) 

8 (17%) 

(47) 

1 (2%) 

1 (2%) 

(49) 

(7) 

20 (41%) 

6 (12%) 

(47) 

1 (2%) 

(48) 

9 (19%) 

3 (6%) 

1 (2%) 

1 (2%) 

(47) 

2 (4%) 

1 (2%) 

(49) 

(43) 

2 (5%) 

(48) 

(8) 

21 (44%) 

5 (10%) 

(50) 

20 (40%) 

2 (4%) 

1 (2%) 

(5) 

1 (13%) 

2 (25%) 

1 (13%) 

(49) (49) 

1 (2%) 

1 (2%) 

(47) (47) 

3 (6%) 

(49) 

1 (2%) 

1 (2%) 

4 (8%) 

12 (24%) 

3 (6%) 

(49) 

2 (4%) 

1 (2%) 

2 (4%) 

9 (18%) 

1 (2%) 

2 (4%) 

(50) 

(49) 

1 (2%) 

1 (2%) 

Bone 

Musculoskeletal System 

Hyperostosis 

(49) (49) 

1 (2%) 
230 Methylphenidate Hydrochloride, NTP TR 439 

of Methylphenidate Hydrochloride (continued) 

Summary of the Incidence of Nonneoplastic Lesions in Female Mice in the 2-Year Feed Study 

TABLE D5 

Brain 

Nervous System 

2-Year Study (continued) 

Artery, inflammation, chronic 

Mineralization 

Hemorrhage, focal 

Compression 

Artery, inflammation, chronic 

(49) (49) (50) (50) 

36 (73%) 

1 (2%) 

30 (60%) 

1 (2%) 

1 (100%) 

1 (2%) 

1 (2%) 

33 (67%) 32 (64%) 

Spinal cord (1) 

Lung 

Respiratory System 

Alveolar epithelium, hyperplasia 

Thrombosis 

Inflammation, chronic 

Hemorrhage, focal 

Congestion 

Inflammation, chronic 

Nose 

Hyperplasia 

Harderian gland 

Special Senses System 

(2) 

1 (50%) 

Urinary System 

Renal tubule, regeneration 

Renal tubule, necrosis 

Renal tubule, degeneration, granular 

Nephropathy 

Mineralization 

Infarct 

Hyperplasia, lymphoid 

Hemorrhage, focal 

Glomerulosclerosis 

Fatty change 

Congestion 

Kidney 

Inflammation, chronic, focal 

Urinary bladder 

(49) 

7 (14%) 

(43) ' 
231 

APPENDIX E 

GENETIC TOXICOLOGY 

SALMONELLA TYPHIMURIUM MUTAGENICITY TEST PROTOCOL . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232 

TABLE E2 Induction of Sister Chromatid Exchanges in Chinese Hamster Ovary Cells 

TABLE El Mutagenicity of Methylphenidate Hydrochloride in Salmonella trphimruim . . . . . . . '. . . 235 

RESULTS ........................................................................ 233 

CHINESE HAMSTER WARY CEU cyToc~~m~cs PROTOCOLS.. , . , . . . . . . . , . . . . . . , . . . . . . . . , . , 232 

by Methylphenidate Hydrochloride . . . . . . . . . , . . . . . . . . . . . . . . , . . . . . . . . . . . . . . . 240 

TABLE E3 Induction of Chromosomal Aberrations in Chinese Hamster Ovary Cells 

by Methylphenidate Hydrochloride . . . . . . . . . . . . . . . . . . . , . . . . . . . . , , . . . . . . . . . . . 237 
232 Methylphenidate Hydrochloride, NTP TR 439 

GENETIC TOXICOLOGY 

counted following incubation for 2 days at 37" C. 

of minimal glucose agar plates. Histidine-independent mutant colonies arising on these plates were 

I-histidine and d-biotin was added, and the contents of the tubes were mixed and poured onto the surfaces 

Sprague-Dawley rat or Syrian hamster liver) for 20 minutes at 37" C. Top agar supplemented with 

S9 mix (metabolic activation enzymes and cofactors from Aroclor 1254-induced male 

with the Salmonella typhimurium tester strains (TA97, TA98, TA100, TA1535, TA1537) either in buffer or 

to two testing laboratories as a coded aliquot from Radian Corporation (Austin, TX). It was incubated 

Testing was performed as reported by Mortelmans el al. (1986). Methylphenidate hydrochloride was sent 

SALMONELLA ~HZMURIM MUTAGENICITYEST PROTOCOL 

dose. All trials were repeated. 

toxicity was noted in the test performed at SRI, International, and 10,000 @plate was selected as the high 

at Microbiological Associates; slight toxicity was observed in the assays without S9 at 4,OOO pg/plate. No 

doses of methylphenidate hydrochloride. The high dose was limited to 5,000 pg/plate in the test performed 

Each trial consisted of triplicate plates of concurrent positive and negative controls and of at least five 

fold-increase required for a chemical to be judged positive or weakly positive. 

in revertant colonies is observed following chemical treatment. There is no minimum percentage or 

magnitude to support a determination of mutagenicity; A negative response is obtained when no increase 

defined as an increase in revertants that is not dose-related, not reproducible, or is of insufficient 

independent (revertant) colonies in any one strain/activation combination. An equivocal response is 

In this assay, a positive response is defined as a reproducible, dose-related increase in histidinesingle flask per dose was used. 

of at least three doses of methylphenidate hydrochloride; the high dose was limited by toxicity. A 

bromodeoxyuridine-substituted DNA. Each test consisted of concurrent solvent and positive controls and 

liver S9 and cofactor mix. Cultures were handled under gold lights to prevent photolysis of 

aberrations (Abs) both in the presence and absence of Aroclor 1254-induced male Sprague-Dawley rat 

hamster ovary (CHO) cells for induction of sister chromatid exchanges (SCES) and chromosomal 

two testing laboratories as a coded aliquot by Radian Corporation. It was tested in cultured Chinese 

Testing was performed as reported by Galloway et al. (1987). Methylphenidate hydrochloride was sent to 

CHINESE HAMSTER OVARY CELL CYTOGENETICS PROTOCOLS 

lengthened to ensure a sufficient number of scorable (second-division metaphase) cells. 

cycle delay was seen in the trial performed without S9 at Litton Bionetics, Inc. (LBI), incubation time was 

were scored for frequency of SCEs/cell from each dose level. Because significant chemical-induced cell 

blind and those from a single test were read by the same person. Fifty second-division metaphase cells 

2 hours. Harvesting and staining were the same as for cells treated without S9. All slides were scored 

hydrochloride, and incubation proceeded for an additional 26 hours, with Colcemid present for the final 

medium was then removed and replaced with medium containing serum and BrdU and no methylphenidate 

S9, cells were incubated with methylphenidate hydrochloride, serum-free medium, and S9 for 2 hours. The 

harvested by mitotic shake-off, fixed, and stained with Hoechst 33258 and Giemsa. In the SCE test with 

fresh medium plus BrdU and Colcemid, and incubation was continued for 2 hours. Cells were then 

After 26 hours, the medium containing.methy1phenidate hydrochloride was. removed and replaced with 

serum, I-glutamine, and antibiotics. Bromodeoxyuridine (BrdU) was added 2 hours after culture initiation. 

26 hours with methylphenidate hydrochloride in McCoy's 5A medium supplemented with fetal bovine 

Sister Chod Exchange Test: In the SCE test without S9, CHO cells were incubated for approximately 
Genetic Toxicology 233 

analyses as well as the biological information available to the reviewers. 

led to a call of equivocal. Ultimately, the trial calls were based on a consideration of the statistical 

A statistically significant trend (P<O.O5), in the absence of any responses reaching 20% above background, 

evidence of activity; increases at two or more doses resulted in a determination that the trial was positive. 

dose points is less than 0.001. An increase of 20%, or greater, at any single dose, was considered weak 

occurring by chance at one dose point is less than 0.01; the probability for such a chance occurrence at two 

chosen as a statistically conservative positive response. The probability of this level of difference 

points (Galloway et al., 1987). An SCE frequency 20% above the concurrent solvent control value was 

Statistical analyses were conducted on the slopes of the dose-response curves and the individual dose 

without S9 at LBI. 

because cell cycle delay was anticipated, the incubation period was extended in the one trial performed 

The harvest time for the Abs test was based on the cell cycle information obtained in the SCE test: 

present for the final 2 hours. Cells were harvested in the same manner as for the treatment without S9. 

treatment medium was removed and the cells incubated for 8 to 10 hours in fresh medium, with Colcemid 

test with S9, cells were treated with methylphenidate hydrochloride and S9 for 2 hours, after which the 

2 hours. The cells were then harvested by mitotic shake-off, fixed, and stained with Giemsa. For the Abs 

with methylphenidate hydrochloride for 10 to 11 hours; Colcemid was added and incubation continued for 

CIvomosomal-m Td: In the Abs test without S9, cells were incubated in McCoy's 5A medium 

and other (pulverized cells, despiralized chromosomes, and cells containing 10 or more aberrations). 

aberrations included simple (breaks and terminal deletions), complex (rearrangements and translocations), 

person. Where possible, 100 first-division metaphase cells were scored at each dose level. Classes of 

(21 f 2 chromosomes). All slides were scored blind and those from a single test were read by the same 

Cells were selected for scoring on the basis of good morphology and completeness of karyotype 

reviewers. 

were based on consideration of the statistical analyses as well as the biological information available to the 

increase at any one dose point, led to an equivocal call (Galloway et al., 1987). Ultimately the trial calls 

more doses indicated the trial was positive. A positive trend, in the absence of a statistically significant 

trend (P<O.O15) were considered weak evidence for a positive response; significant differences for two or 

points. For a single trial, a statistically significant (PcO.05) difference for one dose point and a significant 

statistical call for a trial, analyses were conducted on both the dose-response curve and individual dose 

Chromosomal aberration data are presented as percentage of cells with aberrations. To arrive at a 

compared to the 10,OOO pg/plate tested at SRI, International. 

the tests performed at Microbiological Associates, limiting the highest dose tested to 5,000 pg/plate, 

rat or Syrian hamster liver S9 (Table El; Mortelmans et aZ., 1986). A slight degree of toxicity was noted in 

or TA1537 when tested at two laboratories with and without Aroclor 1254-induced male Sprague-Dawley 

Methylphenidate hydrochloride was not mutagenic in S. zyphimurium strain TA97, TA98, TA100, TA1535, 

RESULTS 

a weakly positive response observed at LBI in the first trial did not repeat in a second trial, and the SCE 

positive response ranged from 702 to 900 pg/mL, much higher doses than those tested at EHRT. With S9, 

cycle delay induced by treatment with methylphenidate hydrochloride. The doses that produced the 

this trial were harvested 10 hours later than the normal harvest time of 26 hours to offset the severe cell 

positive response was obtained at all three scorable doses in the test performed without S9. The cells in 

negative results were obtained with and without S9. At LBI (data presented in Galloway et al., 1987), a 

hydrochloride. In the SCE test performed at Environmental Health Research and Testing (EHRT), 

shows that the positive responses were recorded in tests that employed higher doses of methylphenidate 

SCEs (Table E2) and Abs (Table E3) between two laboratories. However, closer examination of the data 

In cytogenetic tests with cultured CHO cells, apparently inconsistent results were obtained for induction of 
234 Methylphenidate Hydrochloride, NTP TR 439 

performed at EHRT. 

test with S9 was judged to be negative. This latter result was in agreement with the SCE test with S9 

each of the three doses scored. These tests were not repeated. 

observed without S9 (highest dose, 1,250 pg/mL) but with S9, significant increases in Abs were observed at 

overall results of the test with S9 were considered to be equivocal. At LBI no increase in Abs was 

dose (1,500 pg/mL). However, because no increase in Abs was seen at this dose level in the first trial, the 

trial were again negative, while the second trial showed a strong increase in Abs at the highest scorable 

produced positive responses at the two highest doses (1,750 and 2,OOO pg/mL). With S9, results of the first 

significant increases in Abs were observed in the first trial, but a second trial conducted with higher doses 

The Abs test performed at EHRT gave positive results without S9. "bo trials were performed. No 

combination of in vitro genetic toxicity tests improved upon the predictivity of the Salmonella assay. 

of chemicals that induce Abs were positive in the rodent bioassay. It is also important to note that no 

results in the Salmonella assay for rodent carcinogenicity:. 64% of chemicals that induced SCEs and 73% 

noncarcinogens. Positive results in cultured CHO cell cytogenetic studies are less predictive than positive 

negative predictivity was less precise. Approximately 50% of nonmutagens were also found to be 

carcinogenicity in rodents (89% of Salmonella mutagens were carcinogens in rats and/or mice), the 

and Tennant, 1991). Although a positive result in the Salmonella test was shown to be a good predictor of 

mutagenicity in Salmonella, and carcinogenicity in rats and mice at single or multiple tissue sites (Ashby 

was found to exist among the potential electrophilicity of a chemical (structural alert to DNA reactivity), 

predictive value for rodent carcinogenicity (Tennant et al., 1987; Zeiger et at!, 1990). A strong correlation 

in mammalian cells in vitro. The NTP has evaluated these mutagenicity tests with respect to their 

Methylphenidate hydrochloride did not induce mutations in S. typhimurium, but did induce Abs and SCEs 

.. 
Genetic Toxicology 235 

Mutagenicity of Methylphenidate Hydrochloride in Shneh fyphimuriuma 

TABLE El 

Strain Dose-s9 +lo% hamster S9 +lo% .rat s9 

(&plate) Trial 1 Trial 2 Trial 1 Trial 2 Trial 1 Trial 2 

Study performed at SRI, International 

333 

100 

TAlOO 0 

10,Ooo 

3,333 

1 

Positive control' 

Trial summary 

333 

100 

TAl535 0 

10,OoO 

3,333 

1 to00 

Positive control 

Trial summary 

333 

100 

TAl537 0 

10,Ooo 

3,333 

1 ,Ooo 

Positive control 

Trial summary 

333 

100 

TA98 0 

10,Ooo 

3,333 

1 

Positive control 

Trial summary 

120 f 7.5 

142 f 5.7 

127 f 8.5 

121 f 5.6 

115 f 4.8 

126 f 1.0 

493 f 24.8 

Negative 

41 f 4.3 

40 f 1.9 

33 f 6.2 

38 f 1.2 

34 f 6.5 

32 f 3.0 

531 f 11.7 

Negative 

3 f 0.6 

6 f 1.3 

7 f 1.3 

7 2 0.3 

6 f 1.5 

143 f 22.8 

Negative 

11 f 1.2 

25 f 3.5 

24 -c 3.5 

25 f 1.0 

19 f 1.2 

24 f 2.7 

21 f 1.5 

737 f 15.2 

Negative 

147 f 8.1 

167 f 7.1 

150 f 7.8 

144 f 6.9 

150 f 1.5 

122 f 3.6 

447 f 7.2 

Negative 

19 f 3.7 

29 f 3.5 

28 f 5.0 

25 f 2.4 

22 f 5.0 

23 f 3.1 

385 f 7.1 

Negative 

6 f 0.7 

5 f 1.2 

6 f 1.5 

4 f 1.2 

5 f 0.3 

5 f 0.7 

135 f 21.4 

Negative 

16 f 1.0 

17 f 0.3 

22 f 4.4 

17 f 1.7 

878 f 45.2 

Negative 

16 f 1.2 

18 f 22 

134 f 3.5 

135 f 5.4 

126 f 5.8 

136 f 6.4 

140 f 3.5 

117 f 4.7 

2,193 f 40.6 

Negative 

16 f 1.7 

12 f 2.0 

15 f 3.8 

7 f 0.6 

426 f 8.5 

Negative 

11 f 1.2 

8 f 2.2 

7 f 3.2 

8 f 0.6 

8 f 0.7 

14 f 0.3 

324 f 13.2 

Negative 

13 f 1.9 

10 f 2.5 

43 f 2.0 

41 f 3.4 

35 f 4.0 

43 f 2.6 

36 f 2.6 

34 f 1.0 

1,772 f 33.7 

Negative 

162 f 22.7 

167 f 4.0 

139 f 14.2 

167 f 11.7 

156 f 10.7 

124 f 3.5 

1,577 f 17.7 

Negative 

5 f 1.2 

6 f 0.7 

8 f 2.5 

8 f 1.3 

7 f 0.9 

8 f 2.1 

376 f 36.1 

Negative 

5 f 1.0 

6 f 0.9 

7 f 2.3 

8 f 3.0 

8 f 2.9 

7 f 1.5 

129 f 0.6 

Negative 

33 f 3.0 

28 f 1.5 

33 f 5.2 

33 f 4.7 

29 f 4.4 

31 f 3.8 

1,285 f 87.0 

Negative 

160 f 7.2 

156 f 2.7 

149 f 6.4 

136 f 14.1 

149 f 5.8 

142 f 3.8 

1,082 f 50.9 

Negative 

12 f 2.4 

11 f 1.5 

10 f 2.5 

12 f 2.0 

12 f 0.3 

10 f 2.7 

Negative 

193 f 14.4 

8 2 2.0 

11 f 1.8 

11 f 2.8 

10 f 1.2 

10 f 1.3 

12 f 1.7 

216 f 23.7 

Negative 

36 f 3.5 

39 f 1.7 

37 f 2.8 

29 f 2.0 

37 f 3.4 

28 f 4.3 

983 f 21.0 

Negative 

132 f 8.2 

164 f 9.4 

169 f 15.4 

163 f 4.4 

181 f 2.0 

170 f 15.6 

930 f 108.2 

Negative 

8 f 0.9 

8 f 0.6 

8 f 0.9 

8 f 1.3 

12 f 3.2 

6 f 0.9 

163 f 6.6 

Negative 

4 f 1.5 

9 f 2.3 

10 f 2.2 

7 f 1.2 

6 f 1.5 

7 f 2.5 

185 f 10.4 

Negative 

29 f 6.2 

30 f 5.2 

26 f 3.5 

33 f 2.6 

30 f 1.2 

26 2 0.9' 

727 f 31.3 

Negative 
236 Methylphenidate Hydrochloride, NTP TR 439 

Mutagenicity of Methylphenidate Hydrochloride in Salmoneua typhimm'm (continued) 

TABLE El 

Revertantshlate 

Strain Dose -s9 +hamster S9 +rat s9 

(&plate) Trial 1 Trial 2 10% 30% 10% 30% 

Study performed at Microbiological Associates 

333 

100 

TAlOO 0 

5,OOO 

4,Ooo 

3,333 

1 ,OO0 

Positive control 

Trial summary 

333 

100 

TAl535 0 

5,oOO 

4,ooo 

3,333 

1 

Positive control 

Trial summary 

333 

100 

TA97 0 

5,OO0 

4,000 

3,333 

1 ,OOO 

Positive control 

Trial summary 

333 

100 

TA98 0 

5,000 

4,Ooo 

3,333 

1 ,OO0 

Positive control 

Trial summary 

105 f 8.Od 

104 f 6.4 

111 f 4.9 

102 f 5.9 

113 f 6.0 

114 f 5.8 

494 f 29.8 

Negative 

25 f 2.4d 

30 f 2.9 

26 f 5.3 

23 f 1.2 

26 f 5.1 

25 f 1.9 

253 f 17.5 

Negative 

95 f 4.7 

96 f 1.7 

95 f 4.2 

95 f 8.1 

111 f 5.2 

106 f 4.9 

333 f 8.5 

Negative 

20 f 1.2 

18 f 0.7 

13 f 1.5 

11 f 0.9 

16 f 2.7 

16 f 3.5 

159 f 7.9 

Negative 

87 f 7.5 

85 f ' 4.3 

105 f 3.2 

82 f 7.0 

85 f 10.0 

90 f 3.2 

236 f 8.1 

Negative 

10 f 1.5 

7 f 2.6 

10 f 3.0 

9 f 0.6 

11 f 3.4 

13 f 0.0 

153 f 6.4 

Negative 

83 f 1.7d 

88 f 4.0 

102 f 3.8 

95 f 2.8 

97 f 8.5 

98 f 2.9 

217 f 17.1 

Negative 

28 f 2.3 

19 f 1.0 

25 f 2.8 

27 k 1.3 

23 f 1.3 

19 f 2.7 

244 f 5.8 

Negative 

91 f 5.5 

89 f 2.6 

104 f 9.0 

87 f 9.0 

94 f 3.7 

423 f 19.7 

Negative 

100 2 7.9 

7 f 0.9 

9 f 1.9 

11 f 1.2 

9 f 0.9 

14 f 1.3 

52 f 3.1 

Negative 

10 f 2.2 

122 f 9.4 

126 2 4.0 

122 2 5.0 

129 k 2.9 

125 +- 4.8 

228 2 13.8 

Negative 

131 f 7.2 

27 f 3.7 

25 f 3.9 

30 f 2.6 

22 f 1.9 

24 f 3.5 

156 f 8.6 

Negative 

28 f 4.2 

87 +- 0.9 

77 f 6.4 

79 f 4.4 

90 f 3.3 

99 f 12.3 

250 f 6.1 

Negative 

81 f 0.3 

8 f 0.6 

11 f 0.7 

10 f 3.5 

9 f 0.7 

Negative 

8 f 2.6 

6 f 2.0 

75 -+ 3.8 

126 f 11.8 

130 f 10.3 

122 f 2.5 

122 f 5.5 

130 e 2.7 

416 f 21.4 

Negative 

158 f 3.0 

38 f 2.6 

32 f 1.7 

33 f 4.6 

37 f 1.2 

31 f 2.7 

74 f 1.3 

Negative 

33 f 4.4 

103 f 3.8 

108 f 5.5 

105 f 2.0 

108 f 5.0 

107 f 13.4 

818 f 29.3 

Negative 

105 f 7.3 

10 f 1.7 

9 f 1.2 

7 f 0.3 

11 f 1.5 

7 f 1.7 

187 f 8.4 

Negative 

11 f 1.2 

161 f 6.5 

130 f 13.3 

114 f 11.7 

128 f 2.9 

115 f 3.2 

1,375 f 54.2 

Equivocal 

124 f 2.7 

27 f 2.1 

23 f 1.5 

27 f 2.0 

34 f 3.3 

28 f 0.6 

280 f 4.1 

Negative 

32 f 4.0 

95 f 7.8 

86 f 8.0 

87 f 7.9 

90 f 7.9 

96 f 5.2 

477 f 1.5 

Negative 

98 -+ 22 

9 f 1.3 

9 f 1.2 

9 f 0.9 

9 f 0.9 

9 f 0.9 

78 f 2.4 

Negative 

7 f 0.6 

163 f 5.8 

157 2 5.6 

126 f 2.1 

116 f 7.0 

126 f 12.0 

128 f 4.6 

Equivocal 

420 f 10.4 

40 f 6.4 

36 f 1.2 

35 f 6.7 

43 f 3.0 

34 f 1.8 

116 f 6.1 

Negative 

32 & 2.5 

a The detailed protocol and these data are presented in Mortelmans et al. (1986). 0 bg/plate dose is the solvent control. 

Slight toxicity 

on TA1537 and TA97. 

4-nitro+-phenylenediamine was tested on TA98, sodium azide was tested on TAl00 and TA1535, and 9-aminoacridine was tested 

Positive control; 2-aminoanthracene was used on all strains in the presence of S9. In the absence of metabolic activation, 

Revertants are presented as mean f the standard error from three plates. 
Genetic Toxicology 237 

by Methylphenidate Hydrochloridea 

Induction of Sister Chromatid Exchanges in Chinese Hamster Ovary Cells 

TABLE E2 

(&mL) Cells somes SCEs some Cell in BrdU 

No. of scw Relative SCEs/ 

Compound Dose Total Chromo- No. of Chromo- SCEs/ Hrs Chromosome 

%b 

Study performed at Environmental Health Research & Testing 

Summary: Negative 

-s9 

Medium 50 1,023 35 1 0.34 7.0 26.5 

Mitomycin-C 0.003 50 1,041 1,183 1.13 23.7 26.5 231.22 

0.005 50 1,043 1,254 1.20 25.1 26.5 250.42 

Methylphenidate hydrochloride 

500 0 

160 50 1,046 416 0.39 8.3 26.5 15.91 

50 50 1,035 373 0.36 7.5 26.5 5.04 

16 50 1,035 417 0.40 8.3 26.5 17.43 

5 50 1,033 377 0.36 7.5 26.5 6.37 

1.000 0 

Summary: Weakly positive 

Trial 1 

+s9 

Medium 

Cyclophosphamide 1.5 

Methylphenidate hydrochloride 

2,000 

1,600 

1000 

500 

160 

50 

Summary: Negative 

Trial 2 

Methylphenidate hydrochloride 

Cyclophosphamide 

Medium 

2 

1,750 

1,500 

1,250 

1,000 

50 

50 

50 

50 

50 

50 

50 

0 

50 

50 

50 

50 

50 

50 

0 

1,039 

1,044 

1,043 

1,043 

1,040 

1,047 

1,041 

1,044 

1,042 

1,042 

1,041 

1,043 

1,031 

390 0.37 7.8 26.5 

1,235 1.18 24.7 26.5 218.19 

368 0.35 7.4 26.5 -5.37 

422 0.40 8.4 26.5 7.89 

368 0.35 7.4 26.5 -5.28 

351 0.33 7.0 26.5 -9.92 

502 0.48 10.0 26.5 28.84. 

P=O.O15 

427 0.40 8.5 26.0 

2,001 1.91 40.0 26.0 367.73 

414 0.40 8.3 26.0 -2.01 

411 0.39 8.2 26.0 -3.84 

507 0.48 10.1 26.0 18.85 

496 0.47 9.9 26.0 16.16 

26.0 

P < 0.001 
238 Methylphenidate HydmchIoride, NTP TR 439 

by Methylphenidate Hydrochloride (continued) 

Induction of Sister Chromatid Exchanges in Chinese Hamster Ovary Cells 

TABLE E2 

(Ir%mL) Cells somes SCEs some Cell in BrdU % 

No. of scw Relative SCW 

Compound Dose Total Chromo- No. of Chromo- SCw Hrs Chromosome 

- 

Study performed at Litton Bionetics, Inc 

Summary: Positive 

-s9 

Distilled water 

Mitomycin-C 

0.010 

0.001 

Methylphenidate hydrochloride 

900 

800 

702 

1,oo 

50 1,034 388 0.37 7.8 26.0 

50 1,023 644 0.62 12.9 26.0 67.76 

5 105 21 1 2.00 42.2 26.0 435.53 

50 1,013 464 0.45 9.3 36.6d 22.07. 

50 1,010 505 0.50 10.1 36.6' 33.252 

50 1,016 575 0.56 11.5 36.6d 50.822 

0 36.6 

P<O.001 

Summary: Weakly positive 

Trial 1 

+s9 

Distilled water 

Cyclophosphamide 

2.0 

0.3 

Methylphenidate hydrochloride 

Summary: Negative 

Trial 2 

Cyclophosphamide 

Distilled water 

Methylphenidate hydrochloride 

1,750 

1,500 

2,500 

5 

50 

50 

50 

50 

50 

5 

50 

50 

50 

50 

50 

0 

104 

1,025 

1,031 

1,029 

1,041 

1,035 

104 

1,008 

1,019 

1,020 

1,015 

1,020 

391 0.37 

474 0.46 

119 1.14 

448 0.43 

470 0.45 

474 0.46 

P=O.002 

522 0.51 

678 0.67 

250 2.40 

538 0.52 

583 0.57 

594 0.58 

P=O.o06 

23.8 

9.5 

7.8 

9.5 

9.4 

9.0 

50.0 

13.6 

10.4 

11.9 

11.7 

10.8 

25.7 

25.7 

25.7 

25.7 

25.7 

25.7 

25.3 

25.3 

25.3 

25.3 

25.3 

25.3 

201.72 

21.94 

21.46' 

19.05 

14.14 

369.26 

31.30 

13.68' 

12.13 

2.97 
Genetic Toxicology 239 

by Methylphenidate Hydrochloride (continued) 

Induction of Sister Chromatid Exchanges in Chinese Hamster Ovary Cells 

TABLE E2 

l (P<O.Ol) 

a SCE=sister chromatid exchange; BrdU=bromodeaxyuridine. A detailed description of the protocol and the data for the Litton 

proportion of second-division cells available for analysis. 

Because methylphenidate hydrochloride induced adelay in the cell division cycle, hawest time was extended to maximize the 

Significance of relative SCEdchromosome tested by the linear regression trend test vs. log of the dose. 

SCEs/chromosome of culture exposed to methylphenidate hydrochloride relative to those of culture exposed to solvent. 

Bionetics, Inc., study are presented in Galloway et al. (1987). 

e Confluence reduced by approximately 80% evidence of severe toxicity. 
240 Methylphenidate Hydrochloride, NTP TR 439 

by Methylphenidate Hydrochloride 

Induction of Chromosomal Aberrations in Chinese Hamster Ovary Cells 

TABLE E3 

-s9 

&mL Cells Abs Cell Cells pg/mL Cells Abs Cell Cells 

Dose . Total No. of Abs/ Percent ~ Dose , 4 Total No. of Absl Percent 

+ s9 

wlAbs w/Abs 

Study performed at Environmental Health Research and Testing 

Summary: Negative 

Trial 1 - Harvest time: 12.5 hours 

Summary: Negative 

Trial 1 - Harvest time: 12.5 hours 

Medium Medium 

100 3 0.03 3.0 100 1 0.01 1.0 

Mitomycin-C Cyclophosphamide 

0.5 100 103 . 1.03 64.0 50 100 123 1.23 65.0 

Methylphenidate hydrochloride 

50 100 0 0.00 0.0 

16 100 3 0.03 3.0 

Methylphenidate hydrochloride 

160 100 2 0.02 2.0 

500 100 2 0.02 2.0 

1,600 100 2 0.02 2.0 

5,000 0 

16 100 1 0.01 1 .o 

50 100 4 0.04 4.0 

160 100 1 0.01 1.0 

500 100 2 0.02 2.0 

5,000 0 

1,600 100 6 0.06 6.0 

P=0.140b 'I P=O.353 

Summary: Positive 

Trial 2 Harvest time: 12.0 hours 

Summary: Weakly positive 

Trial 2 - Harvest time: 12.0 hours 

Medium , . Medium 

100 0 0.00 0.0 100 . 4 0.04 4.0 

Mitomycin-C 

50 100 57 0.57 41.0 

Cyclophosphamide 

1,750 0 

1,500 100 27 0.27 20.0. 

1,250 100 8 0.08 8.0 

1,000 100 5 0.05 5.0 

Methylphenidate hydrochloride 

0.5 100 51 0.51 38.0 

Methylphenidate hydrochloride 

1,500 100 1 0.01 1 .o 

1,750 100 16 0.16 16.0* 

2,000 100 16 0.16 15.0. 

P<O.OOl P < 0.001 
Genetic Toxicology 241 

by Methylphenidate Hydrochloride (continued) 

Induction of Chromosomal Aberrations in Chinese Hamster Ovary Cells 

TABLE E3 

$9 

&mL Cells Abs Cell Glls 

Dose Total No. of Abd Percent 

+s9 

WiAbs WlAbs 

&mL Cells Abs . Cell Cells 

Dose Total No. of Abs/ Percent 

Study performed at Litton Bionetlcs, Inc 

Summary: Negative 

Harvest time: 21.0 hours’ 

Distilled water 

100 1 0.01 1 .o 

Mitomycin-C 

0.062 50 9 0.18 14.0 

Methylphenidate hydrochloride 

1,500 0 

1,250 100 6 0.06 5.0 

1,Ooo 84 4 0.05 4.0 

750 100 2 02 

.o 

P =o.om 

Summary: Positive 

Harvest time: 10.5 hours 

Distilled water 

100 0 0.00 0.0 

Cyclophosphamide 

25 50 11 0.22 18.0 

1,750 0 

1,500 100 8 0.08 8.0. 

1,250 100 11 0.11 9.0. 

1,OOO 100 11 0.11 8.0* 

Methylphenidate hydrochloride 

P=O.OlO 

l peo.05 a Abs=aberrations. A detailed presentation of the protocol and the data from the Litton Bionetics, Inc., study are presented in 

sufficient metaphase cells at harvest. 

Because of significant chemical-induced cell cycle delay, incubation time prior to addition of &Icemid was lengthened to provide 

Significance of percent cells with aberrations tested by the linear regression trend test vs. log of the dose. 

Galloway et al. (1987). 
242 Methylphenidate Hydrochloride, NTP TR 439 
243 

AND ORGAN-WEXGHT-TO-BODY-WEIGHT RATIOS 

ORGAN WIZIGHTS 

APPENDIX F 

TABLE F3 

TABLE F2 

TABLE F1 

TABLE F4 

TABLE F7 

TABLE F6 

TABLE F5 

TABLE FI3 

of Methylphenidate Hydrochloride 

at the 15-Month Interim Evaluation in the 2-Year Feed Study 

Organ Weights and Organ-Weight-to-Body-Weight Ratios for Mice 

of Methylphenidate Hydrochloride 

at the 9-Month Interim Evaluation in the 2-Year Feed Study 

Organ Weights and Organ-Weight-to-Body-Weight Ratios for Mice 

in the 13-Week Feed Study of Methylphenidate Hydrochloride 

Organ Weights and Organ-Weight-to-Body-Weight Ratios for Mice 

in the 14-Day Feed Study of Methylphenidate Hydrochloride 

Organ Weights and Organ-Weight-to-Body-Weight Ratios for Mice 

of Methylphenidate Hydrochloride 

at the 15-Month Interim Evaluation in the 2-Year Feed Study 

Organ Weights and Organ-Weight-to-Body-Weight Ratios for Rats 

of Methylphenidate Hydrochloride 

at the 9-Month Interim Evaluation in the 2-Year Feed Study 

Organ Weights and Organ-Weight-to-Body-Weight Ratios for Rats 

in the 13-Week Feed Study of Methylphenidate Hydrochloride 

Organ Weights and Organ-Weight-to-Body-Weight Ratios for Rats 

in the 14-Day Feed Study of Methylphenidate Hydrochloride 

Organ Weights and Organ-Weight-to-Body-Weight htios for Rats 

.................... 

245 

244 

................... 

........................................ 246 

........................................ 

249 

248 

247 

.................... 

................... 

........................................ 250 

........................................ 251 
244 Methylphenidate Hydrochloride, NTP TR 439 

of Methylphenidate Hydrochlorid@ 

Organ Weights and Organ-Weight-to-Body-Weight Ratios for Rats in the l4-Day Feed Study 

TABLE F1 

Necropsy body wt 

n 

Male 

Brain 

Relative 

Absolute 

Relative 

Absolute 

Relative 

Absolute 

Relative 

Absolute 

Relative 

Absolute 

Relative 

Absolute 

Relative 

Absolute 

Heart 

R. Kidney 

Liver 

Lungs 

R. Testis 

~Ym~ 

Necropsy body wt 

n 

Female 

Brain 

Relative 

Absolute 

Relative 

Absolute 

Relative 

Absolute 

Relative 

Absolute 

Relative 

Absof u te 

Relative 

Absolute 

Heart 

R. Kidney 

Liver 

Lungs 

Thymus 

5 

216 f 4 

1.95 f 0.07 

0.422 f 0.022 

5.76 f 0.08 

1.242 * 0.016 

5.28 f 0.16 

1.140 f 0.042 

32.06 f 0.39 

6.920 f 0.154 

3.72 f 0.08 

0.803 2 0.022 

3.60 f 0.06 

0.777 f 0.024 

8.22 f 0.23 

1.771 f 0.022 

5 

143 f 2 

2.70 f 0.15 

0.387 f 0.018 

6.76 f 0.33 

0.972 f 0.062 

32.13 f 0.64 

4.603 i 0.101 

4.01 f 0.08 

0.575 f 0.014 

3.73 f 0.10 

0.535 f 0.014 

12.03 f 0.27 

1.723 f 0.024 

5 

215 f 4 

1.91 f 0.18 

0.411 f 0.045 

5.53 f 0.07 

1.186 f 0.011 

5.51 f 0.07 

1.181 f 0.029 

31.93 f 0.64 

6.860 f 0.256 

3.69 f 0.08 

0.793 f 0.025 

3.38 f 0.06 

0.724 f 0.020 

8.42 f 0.16 

1.804 f 0.024 

5 

144 f 2 

2.63 f 0.17 

0.378 f 0.026 

6.54 f 0.13 

0.942 f 0.034 

30.95 f 0.25 

4.452 f 0.061 

3.91 f 0.09 

0.563 f 0.014 

3.59 f 0.11 

0.515 f 0.009 

11.66 f 0.24 

1.675 f 0.014 

5 

216 f 4 

1.89 f 0.15 

0.407 f 0.027 

5.45 f 0.16 

1.177 f 0.029 

5.70 f 0.20 

1.233 f 0.055 

32.59 f 0.53 

7.048 f 0.244 

3.89 f 0.06 

0.839 f 0.012 

3.51 f 0.04 

0.759 f 0.010 

8.30 f 0.25 

1.791 f 0.035 

5 

143 f 1 

2.70 f 0.15 

0.386 f 0.024 

7.03 f 0.21 

1.002 f 0.029 

31.39 f 1.09 

4.479 f 0.190 

3.96 f 0.08 

0.565 f 0.014 

3.92 f 0.21 

0.559 f 0.034 

1201 f 0.16 

1.712 f 0.025 

5 

212 f 2 

1.821 f 0.014 

8.60 f 0.12 

2.03 f 0.11 

0.429 f 0.021 

5.66 f 0.10 

1.198 f 0.022 

5.57 f 0.16 

1.179 f 0.032 

31.43 f 0.37 

6.658 f 0.111 

3.70 f 0.12 

0.783 f 0.027 

3.50 f 0.09 

0.740 f 0.016 

136 f 3 

5 

2.56 f 0.11 

0.347 f 0.012 

6.84 f 0.17 

0.929 f 0.032 

31.22 f 0.40 

4.241 f 0.115 

3.86 f 0.03 

0.524 f 0.007. 

3.67 +- 0.15 

0.499 f 0.021 

12.57 f 0.29 

1.704 f 0.018 

5 

211 f 3 

1.74 f 0.12 

0.367 f 0.028 

5.70 f 0.15 

1.203 f 0.031 

6.00 f 0.25 

1.268 f 0.066 

32.82 f 0.59 

6.929 f 0.203 

3.74 f 0.08 

0.789 f 0.028 

3.32 f 0.06 

0.701 f '0.014. 

8.66 f 0.15 

1.828 f 0.035 

5 

142 f 2 

2.78 f 0.16 

0.392 f 0.018 

6.60 f 0.16 

0.935 f 0.029 

33.15 .C 0.56 

4.698 f 0.096 

4.02 f 0.09 

0.569 f 0.011 

3.74 f 0.03 

0.530 f 0.009 

12.31 f 0.06 

1.744 f 0.014 

1% f 4- 

5 

1.770 f 0.049 

0.832 f O.OBb 

3.63 f 0.15 

0.714 f 0.036. 

9.01 f 0.15.. 

4.22 f 0.13..b 

6.04 f 0.14 

1.186 f 0.021 

5.54 f 0.18 

1.086 f 0.023 

40.16 f 0.87.. 

7.887 f 0.237. 

0.439 f 0.043b ' 

2.21 f 0.22b 

131 f 3.. 

5 

2.75 f O.llb 

0.358 f O.oOab 

7.30 f 0.21 

0.954 f 0.029 

39.05 f 0.95'. 

5.112 f 0.177. 

4.34 f 0.13 

0.567 f 0.016 

3.76 f 0.16 

0.492 f 0.018 

13.20 f 0.27.. 

1.725 f 0.034 

a Organ weights and body weights are given in gram; organ-weight-to-body-weight ratios are given as mg organ weighvg body weight 

. Significantly different (PsO.05) from the control group by Williams' or Dunnett's test 

n=4 

(mean f standard error) 

PSO.01 
Organ Weight Analyses 245 

of Methylphenidate Hydrochloridea 

Organ Weights and Organ-Weight-to-Body-Weight Ratios for Rats in the 13-Week Feed Study 

TABLE F2 

0 PPm 125. ppm 250' ppm 500 PPm 1,Ooo ppm 2,000 ppm 

Necropsy body wt 

n 

Male 

Brain 

Relative 

Absolute 

Relative , 

Absolute 

Relative 

Absolute 

Relative 

Absolute 

Relative 

Absolute 

Relative 

Absolute 

Relative 

Absolute 

Relative 

Absolute 

Heart 

R. Kidney 

Liver 

Lungs 

L. Testis 

R. Testis 

Thymus 

Necropsy body wt 

n 

Female 

Brain 

Relative 

Absolute 

Relative 

Absolute 

Relative 

Absolute 

Relative 

Absolute 

Relative 

Absolute 

Relative 

Absolute 

Heart 

R. Kidney 

Liver 

Lungs 

Thymus 

10 

366 f 7 

0.92 f 0.06 

0.338 f 0.022 

4.05 f 0.06 

1.482 f 0.026 

4.18 f 0.05 

1.531 f 0.023 

4.69 f 0.10 

1.718 f 0.040 

32.64 f 0.62 

11.962 f 0.330 

3.37 f 0.06 

1.234 f 0.036 

2.98 f 0.05 

1.092 f 0.030 

5.45 f 0.11 

1.989 f 0.018 

10 

215 f 4 

1.29 f 0.05 

0.277 f 0.013 

5.84 f 0.17 

1.255 f 0.042 

28.39 f 0.41 

6.098 f 0.079 

3.45 f 0.05 

0.742 f 0.014 

3.40 rf: 0.06 

0.730 f 0.010 

8.76 f 0.17 

1.880 f 0.018 

9 

361 f 8 

0.90 +. 0.06 

0.323 f 0.021 

4.12 f O.llb 

1.498 f 0.054b 

4.23 f 0.05 

1.516 f 0.02 

4.96 f 0.18 

1.788 f 0.073 

33.76 rf: 0.38 

12.173 f 0.296 

3.36 f 0.04 

1.211 f 0.030 

3.05 f 0.03 

1.101 f 0.025 

5.56 f 0.10 

1.999 f 0.019 

zb 

7 

204f2 

1.28 f 0.06 

0.260 f 0.011 

5.83 f 0.12 

1.189 f 0.031 

29.01 rf: 0.58 

5.917 f 0.142 

3.31 f 0.05 

0.675 f 0.014 

3.39 f 0.07 

0.691 & 0.014 

9.01 f 0.07 

1.836 f 0.017 

9 

367 f 9 

3.00 f 0.05 

1.098 f 0.030 

5.52 f 0.12 

2.015 f 0.018 

1.241 ,f 0.024 

4.20 f 0.08 

1.538 f 0.031 

5.01 t 0.15 

1.830 f 0.040 

33.65 f 0.29 

12.339 f 0.341 

3.39 f 0.05 

- C 

0.93 f 0.06 

0.340 f 0.023 

10 

204 f 4 

1.29 f 0.04 

0.262 f 0.008 

6.08 & 0.11 

1.241 f 0.032 

28.99 f 0.64 

5.916 f 0.147 

3.47 f 0.05 

0.708 f 0.007 

3.37 f 0.04 

0.688 zt 0.014 

9.15 f 0.16 

1.864 f 0.013 

10 

348 f 7 

5.95 f 0.13** 

2.062 f 0.009* 

0.85 f 0.04 

0.297 f 0.012 

4.10 f 0.06 

1.422 f 0.016 

4.26 f 0.07 

1.480 f 0.022 

4.99 f 0.12 

1.735 f 0.046 

34.39 f 0.88 

11.943 f 0.252 

3.49 f 0.12 

1.210 f 0.027 

3.10 f 0.06 

1.078 f 0.026 

10 

209 f 3 

1.29 f 0.07 

0.271 f 0.018 

5.85 f 0.12 

1.221 f 0.031 

29.67 rf: 0.31 

6.197 f 0.117 

3.52 f 0.04 

0.734 f 0.012 

3.31 f 0.06 

0.691 f 0.015 

9.10 f 0.08 

1.899 f 0.017 

10 

351 f 6 

5.84 f O.ll** 

2.043 f 0.019* 

1.302 f 0.026 

3.03 f 0.05 

1.062 f 0.021 

3.71 f 0.04.. 

12.916 f 0.386 

4.32 f 0.07 

1.516 f 0.028 

4.91 f 0.14 

1.726 rf: 0.064 

36.76 f 0.65.. 

- 

0.89 f 0.04 

0.314 f 0.014 

10 

204 f 4 

1.908 f 0.028 

0.750 f 0.025 

3.30 f 0.07 

0.672 f 0.016. 

9.40 f 0.19** 

3.68 f 0.07** 

1.38 f 0.06 

0.282 f 0.017 

5.89 f 0.09 

1.199 f 0.026 

31.13 f 0.50** 

6.347 f 0.198 

10 

347 f 6 

5.86 f 0.08.. 

2.025 f 0.009. 

1.316 f 0.030 

2.98 f 0.05 

1.033 f 0.029 

0.94 f 0.04 

0.327 f 0.017 

4.19 f 0.05 

1.452 f 0.019 

4.38 f 0.05' 

1.516 f 0.025 

5.52 f 0.59 

1.903 f 0.190 

40.44 f 1.06** 

14.010 f 0.400.* 

3.80 f 0.07** 

10 

207 f 3 

1.940 f 0.024 

0.770 f 0.017 

3.33 f 0.05 

0.689 f 0.015' 

9.40 f 0.19** 

7.064 f 0.154** 

3.72 f 0.05** 

1.41 f 0.07 

0.291 rf: 0.016 

6.08 f 0.12 

1.255 f 0.019 

34.16 f 0.41** 

a Organ weights and body weights are given in grams; organ-weight-to-body-weight ratios are given as mg organ weight/g body weight 

*. PSO.01 

* Significantly different (PSO.05) from the control group by Williams' or Dunnett's test 

Organ not examined to allow SMVCE procedures to be performed 

n=8 

(mean rt standard error) 
246 Methylphenidate Hydrochloride, NTP TR 439 

in the 2-Year Feed Study of Methylphenidate Hydrochloridea 

Organ Weights and Organ-Weight-to-Body-Weight Ratios for Rats at the %Month Interim Evaluation 

TABLE F3 

Necropsy body wt 

n 

Male 

410 f 14 

10 10 

406f9 388 f 11 

10 9 

388f9 

Brain 

Relative 

Absolute 

Relative 

Absolute 

Relative 

Absolute 

Relative 

Absolute 

R. Kidney 

Liver 

R. Testis 

5.11 f 0.18 

2.074 * 0.029 

5.03 f 0.18 

2.029 2 0.039 

5.30 f 0.11 

2.045 * 0.027 

5.37 f 0.14 

2.076 f 0.019 

3.59 f 0.11 

1.465 f 0.045 

3.55 f 0.11 

1.442 f 0.044 

3.94 f 0.08* 

1.530 f 0.057 

3.87 f 0.10* 

1.500 f 0.048 

38.01 f 0.67 

15.558 f 0.548 

38.76 f 1.32 

15.723 f 0.555 

39.49 f 1.39 

15.341 f 0.720 

42.09 f 0.90* 

16.348 f 0.565 

3.56 f 0.08 

1.451 rt 0.031 

3.56 f 0.06 

1.444 f 0.038 

3.74 f 0.09 

1.448 f 0.038 

3.85 f 0.08. 

1.490 f 0.028 

Necropsy body wt 

n 

Female 

Brain 

Relative 

Absolute 

Relative 

Absolute 

Relative 

Absolute 

R. Kidney 

Liver 

212 f 3.. 

10 

214 f 3** 

10 10 

237 f 5 

10 

227 f 4 

7.75 f 0.19 

1.827 f 0.031 

8.29 f 0.17. 

1.880 f 0.023 1.825 f 0.037 

8.64 f 0.21** 9.01 f 0.11.' 

1.926 f 0.018. 

3.68 f 0.08 

0.778 f 0.019 

3.75 f 0.10 

0.803 f 0.028 

3.58 f 0.11 

0.843 f 0.023 

3.68 f 0.05 

0.835 f 0.007 

34.19 f 0.95 

8.066 f 0.225 

34.10 f 1.09 

7.749 0.272 

32.66 f 0.81 

6.903 2 0.168*' 

34.12 rt 0.48 

7.291 2 0.061.. 

a Organ weights and body weights are given in grams; organ-weipht-to-body-weight ratios are given as mg organ weight& body weight 

** PSO.01 

* Significantly different (PSO.05) from the control group by Williams' or Dunnett's test 

(mean f standard error) 
Organ Weight Analyses 247 

in the 2-Year Feed Study of Methylphenidate Hydrochloride? 

Organ Weights and Organ-Weight-to-Bodyweight Ratios for Rats at the 15-Month Interim Evaluation 

TABLE F4 

n 

Male 

NecropsybodyW 

Brain 

Relative 

Absolute 

Relative 

Absolute 

Relative 

Absolute 

Relative 

Absolute 

R. Kidney 

Liver 

R. Testis 

N=-opsybodyW 

n 

Female 

Brain 

Relative 

Absolute 

Relative 

Absolute 

Relative 

Absolute 

R. Kidney 

Liver 

407 f 17 

10 

3.73 f 0.15 

1.511 f 0.068 

37.79 f 1.13 

15.355 f 0.683 

3.82 f 0.15 

1.541 f 0.048 

5.08 f 0.22 

2.038 f 0.025 

288 f 12 

10 

32.98 f 0.52 

9.483 f 0.437 

3.46 f 0.07 

0.991 f 0.031 

6.52 f 0.21 

1.850 f 0.018 

411 i 12 

10 

4.60 * 0.50 

1.855 f 0.159 

40.01 f 1.31 

16.426 f 0.646 

4.01 f 0.06 

1.652 i 0.063 

4.99 f 0.14 

2.040 f 0.030 

10 

278 f 5 

34.84 * 0.80 

9.681 f 0.226 

3.47 f 0.08 

0.964 f 0.027 

6.67 i 0.12 

1.851 f 0.019 

399 f 14 

10 

3.68 f 0.18 

1.458 i 0.067 

41.69 f 1.04. 

16.640 f 0,747 

4.05 i 0.13 

1.610 f 0.062 

5.31 * 0.18 

2.095 f 0.017 

242 f 6.. 

10 

1.840 i 0.043 

7.61 f 0.19.. 

35.15 f 0.65. 

8.525 f 0.281. 

3.71 f 0.14 

0.899 f 0.039 

10 

377 f 6 

5.54 f 0.09 

2.081 f 0.015 

1.610 f 0.027 

4.29 f 0.10** 

15.784 f 0.261 

41.96 i 0.60.. 

4.78 f 0.58 

1.806 f 0.219 

217 f 3.. 

10 

1.871 f 0.029 

8.63 f 0.18.. 

3.81 f 0.13. 

0.826 f 0.032.' 

35.10 f 0.84' 

7.611 f 0.192.. 

' Organ weights and body weights are given in grams; organ-weight-to-body-weight ratios are given as mg organ weight& body weight 

.. PSO.01 

l Significantly different (PSO.05) from the control group by Williams' or Dunnett's test 

(mean f standard error) 
248 Methylphenidate Hydrochloride, NTP TR 439 

of Methylphenidate Hydrochloridea 

Organ Weights and Organ-Weight-to-Bodyweight Ratios for Mice in the 14-Day Feed Study 

TABLE F5 

0 PPm 250 ppm 1,000 ppm 4,000 ppm 

Necropsy body wt 

n 

Male 

Brain 

Relative 

Absolute 

Relative 

Absolute 

Relative 

Absolute 

Relative 

Absolute 

Relative 

Absolute 

Relative 

Absolute 

Relative 

Absolute 

Heart 

R. Kidney 

Liver 

Lungs 

R. Testis 

Thymus 

Necropsy body wt 

n 

Female 

Brain 

Relative 

Absolute 

Relative 

Absolute 

Relative 

Absolute 

Relative 

Absolute 

Relative 

Absolute 

Relative 

Absolute 

Heart 

R. Kidney 

Liver 

Lungs 

Thymus 

24.2 f 0.5 

5 

2.01 f 0.29 

0.048 f 0.006 

4.27 f 0.09 

0.103 f 0.002 

7.85 f 0.20 

0.190 f 0.003 

36.53 f 0.38 

0.884 f 0.018 

8.03 f 0.22 

0.194 f 0.004 

5.42 f 0.26 

0.131 f 0.007 

19.28 f 0.34 

0.466 f 0.006 

20.1 f 0.3 

5 

8.99 f 0.15 

0.181 f 0.005 

42.10 f 1.74 

0.846 f 0.042 

7.28 f 0.32 

0.146 f 0.008 

5.42 f 0.28 

0.109 f 0.005 

22.11 f 0.59 

0.444 f 0.017 

0.071 f 0.003 

3.52 f 0.13 

26.2 f 0.9 

5 

8.06 k 0.17 

0.211 f 0.007* 

5.39 f 0.29 

0.142 f 0.011 

18.08 f 0.57 

0.471 f 0.003 

1.97 t 0.15 

0.051 2 0.004 

3.97 f 0.13 

0.104 t 0.003 

7.69 f 0.15 

0.201 2 0.009 

39.12 2 0.50** 

1.023 2 0.034** 

19.6 * 0.7 

5 

3.67 k 0.12 

0.072 f 0.002 

9.93 f 0.65 

0.194 2 0.009 

41.67 k 1.11 

0.818 f 0.036 

7.71 -c 0.17 

0.151 k 0.004 

5.30 f 0.22 

0.104 k 0.004 

23.32 f 0.54 

0.456 f 0.006 

25.8 f 0.5 

5 

8.08 f 0.15 

0.208 f 0.003 

4.99 f 0.15 

0.128 f 0.004 

18.25 f 0.33 

0.470 f 0.005 

1.69 f 0.18 

0.043 f 0.004 

3.92 f 0.10 

0.101 f 0.001 

7.85 f 0.28 

0.202 f 0.008 

40.34 f 0.56** 

1.040 f 0.033.. 

18.9 f 0.2 

5 

3.31 f 0.15 

0.063 f 0.003 

9.64 f 0.35 

0.182 f 0.007 

39.29 f 0.75 

0.742 f 0.014 

7.58 f 0.06 

0.143 f 0.002 

5.53 f 0.05 

0.105 f 0.001 

23.65 f 0.51 

0.447 f 0.011 

24.4 f 0.3 

5 

8.13 & 0.14 

0.198 f 0.004 

5.03 f 0.29 

0.122 .c 0.006 

18.96 f 0.38 

0.462 f 0.006 

1.97 f 0.17 

0.048 f 0.004 

4.10 f 0.16 

0.100 -+ 0.004 

8.88 f 0.30 

0.216 * 0.007 

41.36 f 0.39** 

1.007 f 0.015** 

19.6 f 0.5 

5 

0.146 f 0.006 

5.06 f 0.16 

0.099 f 0.005 

23.64 f 0.59 

0.462 f 0.009 

7.45 f 0.i~ 

3.37 f 0.17 

0.066 f 0.004 

9.87 f 0.52 

0.194 f 0.014 

41.30 f 1.93 

0.812 f 0.058 

23.9 f 0.6 

5 

8.25 It 0.17 

0.197 f 0.003 

5.34 f 0.39 

0.128 f 0.010 

19.04 f 0.57 

0.454 f 0.009 

1.74 f 0.17 

0.042 -t 0.004 

4.41 k 0.13 

0.105 -C 0.003 

8.56 f 0.73b 

0.203 f 0.012b 

45.87 f 0.60** 

1.095 f 0.025** 

19.0 f 0.2 

5 

0.110 f 0.009 

24.28 f 0.28 

0.460 f 0.008 

5.84 r 0.54 

2.97 f 0.28 

0.056 f 0.005, 

9.67 f 0.32 

0.183 f 0.007 

46.77 f 0.91’ 

0.887 f 0.020 

8.06 f 0.25 

0.153 f 0.005 

24.1 f 0.4 

2 

8.61 f 0.13 

0.207 f O.OO0 

5.30 f 0.15 

0.128 f 0.006 

20.17 f 0.46 

0.485 f 0.004 

1.52 2 0.21 

0.037 f 0.005 

4.36 f 0.14 

0.105 -r- 0.005 

8.95 f 0.93 

0.216 f 0.026 

77.00 f 2.12- 

1.851 f 0.024** 

18.4 zk 0.2.. 

5 

6.97 f 0.69 

0.128 f 0.013 

6.39 f 0.49 

0.118 f 0.009 

22.05 f 2.04 

0.407 f 0.039 

9.94 f 0.70 

0.183 f 0.014 

72.96 f 1.26** 

1.344 f 0.030.. 

2.45 & 0.32.. 

0.045 f 0.006** 

a Organ weights and body weights are given in grams; organ-weight-to-body-weight ratios are given as mg organ weight/g body weight 

** PSO.01 

l Significantly different (PSO.05) from the control group by Williams’ or Dunnett’s test 

b n=4 

(mean f standard error) 
Organ Weight Analyses 249 

of Methylphenidate Hydrochloride' 

Organ Weights and Organ-Weight-to-Bodyweight Ratios for Mice in the 13-Week Feed Study 

TABLE F6 

125 ppm 250 ppm 

Necropsy body wt 

n 

Male 

Brain 

Relative 

Absolute 

Relative 

Absolute 

Relative 

Absolute 

Relative 

Absolute 

Relative 

Absolute 

Relative 

Absolute 

Relative 

Absolute 

Relative 

Absolute 

Heart 

R. Kidney 

Liver 

Lungs 

L. Testis 

R. Testis 

Thymus 

Necropsy body wt 

n 

Female 

Brain 

Relative 

Absolute 

Relative 

Absolute 

Relative 

Absolute 

Relative 

Absolute 

Relative 

Absolute 

Relative 

Absolute 

Heart 

R. Kidney 

Liver 

Lungs 

Thymus 

36.1 f 0.5 

9 

1.21 f 0.12 

0.043 f 0.004 

3.61 f 0.07 

0.130 f 0.003 

3.27 f 0.06 

0.118 f 0.002 

6.76 f 0.17 

0.244 f 0.007 

41.79 f 0.96 

1.510 f 0.038 

8.73 f 0.13 

0.315 f 0.005 

4.91 f 0.16 

0.177 f 0.006 

12.89 f 0.17 

0.465 f 0.002 

25.5 f 0.9 

10 

1.74 f 0.07 

0.044 f 0.002 

8.16 f 0.25 

0.207 f 0.006 

41.49 +. 1.13 

1.052 f 0.026 

7.30 f 0.16 

0.185 f 0.004 

5.29 f 0.21 

0.134 f 0.004 

19.10 f 0.59 

0.483 f 0.008 

33.6 f 0.6' 

10 

1.18 f 0.09 

0.040 f 0.003 

3.84 f 0.09 

0.129 f 0.002 

3.56 f 0.05. 

0.119 f 0.002 

6.66 f 0.14 

0.223 f 0.005 

46.70 f 0.90. 

1.567 f 0.035 

9.24 f 0.10 

0.310 f 0.005 

5.06 f 0.16 

0.170 f 0.005 

14.30 f 0.34. 

0.478 f 0.006 

26.7 f 0.4 

10 

1.93 f 0.09 

0.051 f 0.002 

8.50 f 0.51 

0.226 f 0.012 

42.94 f 0.60 

1.144 f 0.012. 

7.13 f 0.21 

0.190 f 0.005 

5.02 f 0.08 

0.134 f 0.003 

18.03 f 0.48 

0.479 f 0.008 

32.3 f 1.3.; 

10 

0.119 f 0.003 

7.03 f 0.20 

0.227 f 0.010 

48.54 f 1.36.' 

1.580 f 0.092 

9.14 f 0.30 

0.293 f 0.010 

5.12 f 0.08 

0.165 f 0.006 

14.90 f 0.71** 

0.474 f 0.004 

b 

3.71 f 0.11.. 

- 

1.23 f 0.15 

0.040 k 0.005 

25.7 f 0.5 

10 

1.99 * 0.09 

0.051 f 0.003 

8.55 f 0.64' 

0.218 f 0.015' 

45.08 * 0.77 

1.156 f 0.024. 

7.21 +. 0.07 

0.185 +. 0.004 

5.05 f 0.12 

0.129 f 0.003 

18.81 f 0.47 

0.481 f 0.009 

31.0 f 1.3.' 

10 

0.115 f 0.003 

7.56 f 0.24. 

0.234 f 0.013 

48.01 f 1.51;. 

1.502 f 0.094 

9.60 f 0.16. 

0.297 f 0.013 

5.62 f 0.15. 

0.174 k 0.008 

15.38 f 0.55.' 

0.471 f 0.007 

0.116 f 0.002.' 

3.77 f 0.14.. 

1.25 f 0.11 

0.040 f 0.004 

3.79 f 0.18 

26.4 f 0.5 

10 

1.94 f 0.10 

0.051 f 0.003 

8.19 f 0.27 

0.216 f 0.007 

42.37 f 0.72 

1.117 f 0.026. 

6.92 f 0.12 

0.183 f 0.004 

4.84 f 0.10 

0.128 f 0.003 

18.37 f 0.42 

0.483 f 0.007 

31.6 f 0.4. 

9 

0.314 & 0.006 

5.04 f 0.06. 

0.160 f 0.002' 

15.21 f 0.29.. 

0.481 f 0.007 

0.116 f 0.002 

7.34 f 0.13. 

0.232 2 0.005 

55.64 +. 1.19.. 

1.760 f 0.038. 

9.94 f 0.25- 

3.66 f 0.06.. 

- 

1.43 f 0.07 

0.045 f 0.002 

26.4 f 0.5 

10 

7.07 f 0.16 

0.187 f 0.004 

4.99 f 0.13 

0.132 2 0.003 

18.69 & 0.42 

0.492 f 0.006 

1.89 f 0.16 

0.050 f 0.004 

8.25 f 0.32 

0.218 f 0.009 

47.59 f 0.84'. 

1.258 f 0.032.. 

28.50 f 0.70.. 

10 

0.221 f 0.006 

68.88 f 2.81.. 

1.952 f 0.060'. 

10.62 f 0.52.; 

0.301 f 0.010 

5.42 2 0.17* 

0.153 f 0.002.. 

17.55 f 0.48.. 

0.498 f O.OIOLf 

7.83 f 0.35. 

0.116 f 0.003 

1.35 f 0.12 

0.038 2 0.003 

4.05 f 0.12. 

0.115 f 0.003.. 

4.10 f 0.13.. 

24.8 f 0.3 

10 

7.71 f 0.16 

0.191 f 0.006 

5.66 f 0.08 

0.140 f 0.003 

19.79 f 0.30 

0.489 f 0.007 

1.81 f 0.06 

0.045 f 0.001 

9.52 f 0.35. 

0.235 2 0.009 

55.96 f 0.83.. 

1.385 f 0.030.. 

a Organ weights and body weights are given in grams; organ-weight-to-body-weight ratios are given as mg organ weight/g body weight 

l Significantly different (PSO.05) from the control group by Williams' or Dunnett's test 

Organ not examined to allow SMVCE procedures to be performed 

[mean f standard error) 

PSO.01 

' n=9 
250 Methylphenidate Hydrochloride, NTP TR 439 

in the 2-Year Feed Study of Methylphenidate Hydrochloride* 

Organ Weights and Organ-Weight-to-Bodyweight Ratios for Mice at the 9-Month Interim Evaluation 

TABLE F7 

Necropsybodyw 

n 

Male 

Brain 

Relative 

Absolute 

Relative 

Absolute 

Relative 

Absolute 

Relative 

Absolute 

R. Kidney 

Liver 

R. Testis 

47.0 f 1.2 

10 

46.3 f 0.6 

10 

42.3 f 1.5. 

10 

41.0 f 1.7.. 

10 

9.68 f 0.33 

0.452 f 0.008 

9.79 f 0.16 

0.452 f 0.005 

10.93 f 0.42* 

0.457 f 0.004 

11.03 f 0.41.. 

0.447 f 0.006 

7.28 f 0.13 

0.342 f 0.012 

7.07 f 0.09 

0.327 f 0.006 

7.77 f 0.21 

0.327 f 0.010 0.326 f 0.010 

7.99 f 0.20- 

43.35 f 2.07 

2.054 f 0.143 

42.68 i 1.22 

1.980 f 0.081 

43.53 f 0.44 

1.844 f 0.070 

48.40 f 1.54. 

1.996 f 0.131 

2.78 f 0.09 

0.117 f 0.003 

2.86 2 0.09. 

0.116 f 0.003 

2.60 f 0.05 

0.122 f 0.003 

2.62 f 0.06 

0.121 f 0.004 

42.2 1.7 

10 

38.1 f 1.6 

9 

38.6 f 1.6 

10 

39.8 1.6 

10 

Brain 

Relative 

Absolute 

Relative 

Absolute 

Relative 

Absolute 

R. Kidney 

Liver 

0.463 f 0.004 0.465 f 0.009 

11.13 f 0.45 12.43 f 0.66 

0.472 f 0.007 0.468 +- 0.005 

12.40 f 0.51 11.93 f 0.43 

0.213 f 0.005 0.216 f 0.005 0.217 2 0.007 0.215 f 0.006 

5.08 f 0.15 5.75 f 0.26 5.66 f 0.18 5.47 f 0.20 

1.594 f 0.042 1.599 f 0.040 1.644 f 0.037 1.712 f 0.056 

38.02 f 1.00 42.34 * 1.18. 42.99 f 1.40.. 43.33 f 1.19’. 

t~ Organ weights and body weights are given in grams; organ-weight-to-body-weight ratios are given as mg Organ weight& body weight 

.* PSO.01 

. Significantly different (PSO.05) from the control group by Williams’ or Dunnett’s test 

(mean f standard error) 
Organ Weight Analyses 251 

in the 2-Year Feed Study of Methylphenidatea 

Organ Weights and Organ-Weight-to-Body-Weight Ratios for Mice at the 15-Month Interim Evaluation 

TABLE FS 

0 PPm 250 ppm PPm 

Necropsy body wt 

n 

Male 

Brain 

Relative 

Absolute 

Relative 

Absolute 

Relative 

Absolute 

Relative 

Absolute 

R. Kidney 

Liver 

R. Testis 

Necropsy body wt 

n 

Female 

Brain 

Relative 

Absolute 

Relative 

Absolute 

Relative 

Absolute 

R. Kidney 

Liver 

43.7 f 1.2 

10 

10.44 f 0.30 

0.453 f 0.005 

8.11 f 0.28 

0.352 f 0.009 

42.94 f 1.17 

1.877 f 0.076 

2.70 f 0.10 

0.117 f 0.002 

39.9 f 1.3 

10 

0.463 f 0.007 

11.71 k 0.43 

5.65 f 0.19 

0.224 f 0.008 

38.53 f 1.09 

1.531 f 0.048 

44.6 f 1.8 

10 

8.14 f 0.31 

0.364 f 0.021 

10.08 f 0.31 

0.445 f 0.007 

2.58 f 0.11 

0.114 f 0.004 

49.67 f 1.85;’ 

2.236 f 0.164 

41.9 f 1.6 

10 

11.32 2 0.43 

0.468 f 0.005 

0.243 f 0.010 

41.58 f 1.89 

1.721 f 0.053; 

5.85 f 0.28 

.. 

42.7 f 1.2 

10 

8.42 f 0.26 

0.358 f 0.009 

10.64 f 0.22 

0.453 f 0.009 

0.118 f 0.005b 

49.48 f 1.12.; 

2.116 f 0.089 

2.74 f 0.12b 

39.6 f 2.6 

10 

12.08 2 1.01 

0.456 f 0.005 

5.83 f 0.31 

0.224 f 0.006 

43.84 f 1.98; 

1.695 f 0.061; 

41.0 f 1.8 

9 

2.85 f 0.11 

0.116 f 0.004 

50.27 f 1.96;; 

2.048 f 0.090 

8.55 k 0.18 

0.349 * 0.013 

10.79 f 0.38 

0.438 f 0.008 

43.5 f 1.3 

9 

5.51 f 0.16 

0.239 f 0.007 

10.77 2 0.33 

0.466 f 0.007 

43.75 f 1.00. 

1.903 f 0.069;; 

Significantly different (P<O.O5) from the control group by Williams’ or Dunnett’s test 

a Organ weights and body weights are given in grams; organ-weight-to-body-weight ratios are given as mg organ weight/g body weight 

** PSO.01 

n=9 

(mean * standard error) 
252 Methylphenidate Hydrochloride, NTP TR 439 
253 

RESULTS 

HEMATOLOGY AND CLINICAL CHEMISTRY 

APPENDIX G 

TABLE 62 Hematology and Clinical Chemistry Data for Rats 

TABLE G1 Clinical Chemistry Data for Rats in the 14-Day Feed Study 

at the 15-Month Interim Evaluation in the 2-Year Feed Study 

of Methylphenidate Hydrochloride 

at the 9-Month Interim Evaluation in the 2-Year Feed Study 

of Methylphenidate Hydrochloride 

at the 9-Month Interim Evaluation in the 2-Year Feed Study 

of Methylphenidate Hydrochloride 

of Methylphenidate Hydrochloride 

of Methylphenidate Hydrochloride 

at the 15-Month Interim Evaluation in the 2-Year Feed Study 

of Methylphenidate Hydrochloride 

......................................... 254 

......................................... 255 

TABLE 63 Hematology and Clinical Chemistry Data for Rats 

......................................... 

257 

256 

TABLE G5 Hematology and Clinical Chemistry Data for Mice 

TABLE 64 Clinical Chemistry Data for Mice in the 14-Day Feed Study 

......................................... 

......................................... 258 

TABLE 66 Hematology and Clinical Chemistry Data for Mice 

......................................... 259 
254 Methylphenidate Hydrochloride, NTP TR 439 

Clinical Chemistry Data for Rats in the l4Day Feed Study of Methylphenidate Hydrochlorid@ 

TABLE G1 

n 

Male 

5 5 5 5 5 5 

Urea nitrogen (mg/dL) 17.9 f 0.3 19.9 f 0.7' 19.4 f 0.7 19.3 f 0.4 21.0 f 0.5.. 24.4 f 1.1.. 

Creatinine (mg/dL) 0.90 f 0.00 0.80 f 0.03. 0.74 f 0.02.. 0.80 f 0.03,. 0.68 f 0.02.. 0.64 f 0.04'. 

Alanine aminotransferase (IUL) 31 f 2 27f2 30f2 27 f 2 28fl 29 f 2 

Aspartate aminotransferase. (IUL) 116 f 14 101 f 10 116 f 17 91 f 4 98f4 75 f 2.' 

Sorbitol dehydrogenase (IUL) 8.1 f 0.7 5.5 f 0.6 8.2 f 1.0 7.0 f 1.3 6.3 f 0.7 6.5 f 0.9 

n 

Female 

5 5 5 5 5 5 

Urea nitrogen (mg/dL) 18.8 f 0.4 18.9 f 1.1 22.6 f 0.8.. 22.2 f 0.7.. 23.9 f 0.6.. 26.7 f 1.4.. 

Creatinine (mg/dL) 0.70 f 0.03 0.80 f 0.06 0.72 f 0.06 0.72 f 0.02 0.62 f 0.05 0.58 f 0.06 

Alanine aminotransferase (IUL) 25f3 25f2 26f2 2822 24fl 31 f 3 

Aspartate aminotransferase (IUL) 78 f 8 82 f 9 85 f 8 89 f 13 72 f 4 77 f 8 

Sorbitol dehydrogenase (IU/L) 7.9 f 1.0 7.1 f 0.4 5.5 3: 0.2. 6.9 f 0.7 7.1 f 0.5 6.1 f 0.3b 

a Mean f standard error 

.* PSO.01 

. Significantly different (PsO.05) from the control group by Dunn's or Shirley's test 

n=4 
Hematology and Clinical Chemistry 255 

of Methylphenidate Hydrochloride' 

Hematology and Clinical Chemistry Data for Rats at the 9-Month Interim Evaluation in the 2-Year Feed Study 

TABLE 62 

Hematology 

n 

Male 

Nucleated erythrocytes (103/bL) 

Eosinophils (103/bL) 

Monocytes (103/bL) 

Lymphocytes (103/bL) 

Segmented neutrophils (103/bL) 

Leukocytes (103/pL) 

Reticulocytes (106/bL) 

Mean cell hemoglobin concentration (g/dL) 

'Mean cell hemoglobin (pg) 

Mean cell volume (fL) 

Erythrocytes (106/bL) 

Hemoglobin (g/dL) 

Hematocrit (%) 

Clinical Chemistry 

Aspartate aminotransferase (IUL) 

Alanine aminotransferase (IUL) 

Creatinine (mg/dL) 

Urea nitrogen (mg/dL) 

y-glutamyltransferase (IUL) 

Hematology 

n 

Female 

Nucleated erythrocytes (ld/bL) 

Eosinophils (103/bL) 

Monocytes (103/pL) 

Lymphocytes (103/bL) 

Segmented neutrophils (103/bL) 

Leukocytes (103/bL) 

Reticulocytes (106/bL) 

Mean cell hemoglobin concentration (g/dL) 

Mean cell hemoglobin (pg) 

Mean cell volume (L) 

Erythrocytes (106/bL) 

Hemoglobin (g/dL) 

Hematocrit (%) 

Clinical Chemistry 

Aspartate aminotransferase (IUL) 

Alanine aminotransferase (IUL) 

Creatinine (mg/dL) 

Urea nitrogen (mg/dL) 

y-glutamyltransferase (IUL) 

7 

36.4 f 1.1 

18.5 f 0.4 

50.9 f 0.4 

8.77 f 0.12 

16.2 f 0.2 

44.7 f 0.9 

0.019 f 0.019 

0.09 f 0.03 

0.13 f 0.03 

4.68 f 0.28 

1.89 f 0.29 

6.79 f 0.35 

0.3 f 0.1 

119 f 9 

80 2 3d 

0.58 f 0.02' 

21.1 f 0.6' 

1.8 f 0.4' 

10 

36.9 f 0.4 

19.9 f 0.3 

54.1 f 0.4 

7.83 f 0.11 

15.6 f 0.1 

42.3 f 0.5 

0.024 f 0.013 

0.05 f 0.01 

0.20 * 0.04 

4.45 f 0.26 

0.90 f 0.08 

5.60 f 0.27 

0.2 f 0.0 

0.49 f 0.02 

20.4 f 1.2 

0.6 f 0.2 

74 f 6 

64 f 9 

10 

37.8 f 0.3 

18.9 f 0.2 

50.1 f 0.5 

8.76 f 0.13 

16.6 f 0.2 

43.9 f 0.4 

o.Oo0 f o.Oo0 

0.07 f 0.03 

0.24 f 0.03* 

5.74 f 0.27. 

1.77 f 0.19 

7.81 ? 0.24* 

0.2 f 0.0 

0.54 f 0.03 

22.1 f 0.9 

2.2 f 0.5 

103 f 6 

76 2 6 

10 

36.3 f 0.2 

19.7 f 0.2 

54.1 f 0.5 

7.86 f 0.04 

15.5 f 0.1 

42.6 f 0.3 

0.2 f 0.0 

0.07 f 0.02 

0.27 f 0.03* 

4.34 f 0.19 

1.19 f 0.17 

5.86 f 0.29 

0.007 f 0.007 

0.54 r?: 0.03 

20.2 f 1.0 

0.7 f 0.2 

68 f 6 

53 f 4 

9 

37.7 f 0.2 

18.7 f 0.2 

49.6 f 0.8 

8.73 f 0.11 

16.3 f 0.2 

43.2 f 0.6 

o.Oo0 f o.Oo0 

0.12 * 0.04 

0.21 f 0.04 

5.21 It 0.19 

2.61 f 0.33 

8.16 f 0.42* 

0.2 * 0.0 

108 6' 

64 * 3.' 

0.58 f 0.02' 

19.9 f 0.7' 

1.8 f 0.4' 

10 

37.4 f 0.3 

20.2 f 0.2 

54.0 k 0.3 

7.78 f 0.06 

15.7 k 0.1 

41.9 r?: 0.3 

o.Oo0 f o.Oo0 

0.09 r?: 0.02 

0.39 f 0.06** 

4.90 f 0.22 

1.44 f 0.21** 

6.83 f 0.38* 

0.2 f 0.0 

0.55 f 0.03 

19.9 f 1.0 

0.5 f 0.2 

67 f 3 

49 f 1 

9 

37.1 f 0.6 

18.7 * 0.3 

50.3 f 0.4 

8.60 f 0.20 

16.1 f 0.4 

43.3 f 0.7 

0.009 f 0.009 

0.09 f 0.02 

0.29 f 0.04* 

6.71 f 0.59** 

2.04 f 0.25 

9.13 f 0.66.. 

0.2 f 0.ob 

0.60 f 0.03 

20.9 f 0.5 

2.2 f 0.5 

92 f 5* 

59 2 4** 

10 

36.3 f 0.6 

19.5 f 0.4 

53.8 f 0.6 

7.90 f 0.20 

15.4 f 0.2 

42.4 f 1.0 

0.000 f o.Ooo* 

0.06 f 0.03 

0.41 f 0.07** 

6.18 f 0.15**d 

1.42 f 0.26* 

8.23 f 0.34*** 

0.1 f 0.0 

0.59 f 0.03* 

21.5 f 1.1 

0.9 f 0.2 

67 f 6 

50 f 2 

' Mean f standard error 

** PSO.01 

l Significantly different (PSO.05) from the control group by Dunn's or Shirley's test 

n=8 ' n=10 * n=9 
256 Methylphenidate Hydmhloridq ,NTP TR 439 

of Methylphenidate Hydrochloride' 

Hematology and Clinical Chemistry Data for Rats, at the 15-Month Interim Evaluation in the 2-Year Feed Study 

TABLE 63 

Hematology 

n 

Male 

Nucleated erythrocytes (103/bL) 

Eosinophils (103/bL) 

Monocytes (103/bL) 

Lymphocytes (lo3/&) 

Segmented neutrophils (103/bL) 

Leukocytes (103/bL) 

Reticulocytes (106/pL) 

Mean cell hemoglobin concentration (g/dL) 

Mean cell hemoglobin (pg) 

Mean cell volume (fL) 

Erythrocytes (106/bL) 

Hemoglobin (g/dL) 

Hematocrit*(%) 

Clinical Chemistry 

Aspartate aminotransferase (IUL) 

Alanine aminotransferase (IUL) 

Creatinine (mg/dL) 

Urea nitrogen (mg/dL) 

y-glutamyltransferase (IUL) 

Hematology 

n 

Female 

Nucleated erythrocytes (103/bL) 

Eosinophils (103/pL) 

Monocytes (103/bL) 

Lymphocytes (103/pL) 

Segmented neutrophils (103/bL) 

Leukocytes (103/bL) 

Reticulocytes (106/pL) 

Mean cell hemoglobin concentration (g/dL) 

Mean cell hemoglobin (pg) 

Mean cell volume (fL) 

Erythrocytes (106/bL) 

Hemoglobin (g/dL) 

Hematocrit (%) 

Clinical Chemistry 

Aspartate aminotransferase (IUL) 

Alanine aminotransferase (IUL) 

Creatinine (mg/dL) 

Urea nitrogen (mg/dL) 

y-glutamyltransferase (IUL) . 

10 

36.3 f 0.3 

18.5 f 0.2 

51.0 f 0.4 

8.56 f 0.22 

15.8 f 0.4 

43.5 f 0.9 

0.04 f 0.03 

0.05 f 0.02 

0.60 f 0.07 

3.56 f 0.41 

2.11 f 0.28 

6.43 f 0.52 

0.3 f 0.0 

0.40 f 0.03 

19.5 f 0.7 

2.1 f 0.5 

91 f 6 

83 f 5 

9 

36.3 f 0.2 

20.0 f 0.2 

55.0 f 0.5 

7.83 f 0.11 

15.6 f 0.2 

43.0 f 0.4 

0.05 f 0.02 

0.07 f 0.03 

0.53 f 0.10 

3.08 +. 0.28 

1.41 f 0.16 

5.21 f 0.43 

0.1 f 0.0 

0.37 f 0.03' 

19.5 f 0.8' 

1.8 +. 0.4' 

67 f 3' 

53 f 2' 

10 

36.2 f 0.3 

18.4 f 0.2 

50.9 f 0.5 

8.44 f'O.16 

15.5 f 0.3 

42.9 f 0.7 

0.07 f 0.03 

0.05 f' 0.02 

0.70 f 0.10 

4.70 f 0.41 

2.14 f 0.23 

7.72 f 0.47 

0.3 f 0.0 

.x . 

0.38 f 0.02 

19.9 f 0.6 

2.3 f 0.5 

85 f 6 

65 f 3** 

10 

35.7 f 0.3 

19.6 f 0.1 

54.9 f 0.6 

7.99 f 0.10 

15.6 f 0.1 

43.8 f 0.4 

0.05 f 0.02 

0.05 f 0.02 

0.48 f 0.05 

3.21 f 0.18 

1.09 f 0.10 

4.98 +. 0.25 

0.2 f 0.0 

0.30 f 0.03 

19.3 f 0.8 

2.9 f 0.9 

63 f 2 

56 f 1 

10 

36.9 f 0.3 

18.5 f 0.2 

50.1 f 0.7 

9.03 f 029 

16.7 f 0.5 

45.2 f 1.4 

0.01 f 0.01 

0.05 f 0.02 

0.70 f 0.07 

4.56 f 0.40 

1.79 k 0.26 

7.23 2 0.48 

0.2 f 0.0 

0.38 f 0.03 

19.8 f 0.7 

2.6 f 0.7 

86 f 8 

66 f 5** 

9 

36.0 f 0.4 

19.7 f 0.2 

54.9 f 0.5 

7.94 f 0.19 

15.6 f 0.3 

43.4 f 1.4 

0.02 f 0.01 

0.05 f 0.01 

0.47 f 0.05 

2.91 ? 0.28 

1.13 f 0.08 

4.63 f 0.35 

0.2 f 0.0 

0.36 f 0.03' 

20.8 f 0.9' 

1.7 f 0.5' 

67 f 5' 

58 f 5' 

10 

36.6 f 0.2 

18.6 f 0.1 

50.5 * 0.5 

8.87 zk 0.17 

16.5 zk 0.3 

44.7 f OS 

0.2 f 0.0 

0.00 f 0.00 

0.13 f 0.04, 

0.59 f 0.09 

4.23 f 0.35 

1.71 f O.Zb 

7.57 f 0.v 

0.38 f 0.02 

19.4 f 0.9 

1.5 f 0.5 

92f9 

66 f 8** 

10 

35.9 f 0.2 

19.5 f 0.2* 

54.1 f 0.4 

7.85 f 0.13 

15.3 f 0.2 

42.6 f 0.6 

0.02 f 0.01 

0.06 k 0.01 

0.62 ? 0.10 

3.61 f 0.34 

1.47 f 0.31 

5.94 f 0.70 

0.2 f 0.0 

0.37 f 0.03 

22.2 f 0.7. 

2.3 f 0.6 

76 f 5 

53 f 3 

a Mean f standard emr 

** PSO.01 

* Significantly different (P~0.05) from the control group by Dunn's or Shirley's test 

n=9 n=IO 
Hematology and Clinical Chemistry 257 

Clinical Chemistry Data for Mice in the 14-Day Feed Study of Methylphenidate Hydrochloridd 

TABLE 64 

n 

Male 

5 5 5 5 5 L 

Sorbitol dehydrogenase (IUL) 

Aspartate aminotransferase (IU/L) 

Alanine aminotransferase (IUL) 

Creatinine (mgML) 

Urea nitrogen (mg/dL) 

n 

Female 

166 f 41 

28f6 

0.35 f O.oSb 

27.0 1.4 

20 f le 18 f 2 

161 f 41 

35 f 11 

0.46 f 0.04 

24.8 f 1.4 

20f2 

0.48 f 0.05 

21.9 * 1.5 

20 * 1c 

99 f 16 

21 f 3c 

105 f 35 

24f6 

0.44 f 0.07 

22.7 f 1.2 

16 f 1 

99f8 

22f4 

0.60 f 0.03 

24.0 * 1.0 

203 f 45 

73 f 22 

0.35 f 0.05 

23.1 f 2.3 

41 f 9 

5 5 5 5 5 5 

Sorbitol dehydrogenase (IUL) 

Aspartate aminotransferase (IUL) 

Alanine aminotransferase (ILJL) 

Creatinine (mg/dL) 

Urea nitrogen (mg/dL) 

10 f ld 

112 f 15 

22 f 3 

0.50 f 0.03 

20.9 f 1.1 

23f7 

0.54 f 0.09 

17.9 f 0.7 

14 f Od 

100 f 8 116 f 9 

17 f 1 

0.44 f 0.05 

19.7 f 1.4 

10 f 2b 12 f 3c 

123 f 17 

29 f 3 

0.46 f 0.05 

20.5 f 0.8 

91 f 21 

17 f 4 

20.4 f 0.7 

0.50 f 0.00b 

11 f zc 16 f 2b 

106 f 19 

26f2 

0.44 f 0.05 

23.4 f 1.3 

a Mean f standard error 

n=2 

n-3 

n=4 
258 Methylphenidate Hydrochloride, NTP TR 439 

of Methylphenidate Hydrochloridea 

Hematology and Clinical Chemistry Data for Mice at the 9-Month Interim Evaluation in the 2-Year Feed Study 

TABLE G5 

Hematology 

n 

Male 

Nucleated erythrocytes (103/bL) 

Eosinophils (103/bL) 

Monocytes (103/bL) 

Lymphocytes (103/bL) 

Segmented neutrophils (103/fiL) 

Leukocytes (103/bL) 

Reticulocytes (106/bL) 

Mean cell hemoglobin concentration (g/dL) 

Mean cell hemoglobin (pg) 

Mean cell volume (fL) 

Erythrocytes (106/pL) 

Hemoglobin (g/dL) 

Hematocrit (%) 

Clinical Chemistry 

Aspartate aminotransferase (IUL) 

Alanine aminotransferase (IUL) 

Creatinine (mg/dL) 

Urea nitrogen (mg/dL) 

y-glutamyltransferase (IU/L) 

Hematology 

n 

Female 

Nucleated erythrocytes (103/bL) 

Eosinophils (103/fiL) 

Monocytes (103/pL) 

Lymphocytes (lO'/bL) 

Segmented neutrophils (103/bL) 

Leukocytes (103/pL) 

Reticulocytes (106/bL) 

Mean cell hemoglobin concentration (g/dL) 

Mean cell hemoglobin (pg) 

Mean cell volume (fL) 

Erythrocytes (106/bL) 

Hemoglobin (g/dL) 

Hematocrit (%) 

Clinical Chemistry 

Aspartate aminotransferase (IUL) 

Alanine aminotransferase (IUL) 

Creatinine (mg/dL) 

Urea nitrogen (mg/dL) 

y-glutamyltransferase (IUL) 

10 

34.6 f 0.2 

16.6 f 0.1 

47.9 f 0.2 

9.27 f 0.09 

15.4 f 0.2 

44.5 f 0.4 

0.00 * 0.00 

0.01 f 0.01 

0.10 f 0.03 

2.02 f 0.18 

1.36 f 0.19 

3.52 f 0.31 

0:2 f 0.0 

0.37 f 0.04b 

19.4 f 1.9 

0.9 f 0.4 

221 f 33b 

328 f 59 

10 

35.8 f 0.3 

17.3 f 0.2 

48.1 f 0.4 

9.31 f 0.13 

16.1 f 0.2 

44.9 f 0.5 

0.00 f 0.00 

0.04 f 0.02 

0.03 f 0.01 

2.37 f 0.17 

0.86 f 0.08 

3.30 f 0.23 

0.2 f 0.0 

199 f 40 

175 f 35 

0.32 f 0.04b 

25.9 f 2.1 

3.4 f 2.6 

10 

34.9 f 0.2 

16.8 f 0.1 

48.2 f 0.1 

9.36 f 0.19 

15.7 f 0.3 

45.0 f 0.8 

0.00 f 0.00 

0.03 f 0.01 

0.05 rt 0.02 

1.83 f 0.23 

0.72 f 0.14' 

2.63 k 0.28 

0.2 f 0.0 

281 f 66 

314 f 61 

0.37 f 0.03 

19.7 f 2.8 

2.4 f 0.7b 

9 

36.1 f 0.5 

17.4 f 0.2 

48.3 f 0.5 

9.35 f 0.15 

16.3 f 0.3 

45.1 f 0.7 

0.00 f 0.00 

0.06 f 0.03 

0.03 rt 0.01 

2.68 f 0.19 

1.31 f 0.16 

4.08 * 0.33 

0.1 f 0.0 

134 f 15 

105 f 17 

0.30 f 0.03 

23.4 f 2.4 

1.6 f 1.6 

10 

35.5 f 0.4 

16.9 f 0.2 

48.1 f 0.4 

9.40 f 0.17 

15.9 f 0.3 

44.9 f 0.7 

0.00 f 0.00 

0.01 f 0.01 

0.03 f 0.01* 

1.70 f 0.28 

1.18 f 0.19 

2.94 f 0.31 

0.1 f 0.0 

202 f 28 

234 f 39 

0.36 f 0.02 

16.4 f 1.9 

1.2 f 0.5 

9 

36.0 f 0.5 

17.4 f 0.2 

48.2 f 0.4 

9.38 f 0.20 

16.3 f 0.4 

45.2 f 0.8 

0.00 f 0.00 

0.08 rt 0.02 

0.04 f 0.01 

2.41 f 0.29 

1.09 f 0.13 

3.61 f 0.32 

0.1 f 0.0 

0.34 f 0.03d 

20.5 2 1.7' 

0.9 f 0.9' 

211 f 47' 

86 f lld 

10 

34:6 ? 0.2 , 

16.8 f 0.2 

48.6 f 0.2. 

9.14 f 0.09 

15.4 f 0.1 

44.4 f 0.3 

0.03 f 0.01' 

1.81 f 0.38' 

1.21 f 0.13 

3.12 f 0.40 

0.1 f 0.0 

0.00 f 0.00 

0.,04 f 0.02 

240 k 42 

19.8 f 2.4 

2.4 f 0.2 

2i1 2 35 

0.38 f 0.03b 

10 

35.3 f 0.3 

17.1 f 0.2 

48.6 f 0.3 

9.33 rf: 0.11 

16.0 f 0.2 

45.2 f 0.5 

0.00 * 0.00 

0.06 f 0.01 

0.04 rf: 0.02 

2.11 k 0.27 

1.13 f 0.19 

3.34 f 0.41 

0.1 f 0.0 

126 f lob 

112 f 14b 

0.34 f 0.04 

18.0 f 1.4* 

0.0 f 0.0 

* Significantly different (PSO.05) from the control group by Dunn's or Shirley's test a Mean f standard error 

n=9 ' n=10 n=8 
Hematology and Clinical Chemistry 259 

of Methylphenidate Hydrochloridea 

Hematology and Clinical Chemistry Data for Mice at the 15-Month Interim Evaluation in the 2-Year Feed Study 

TABLE 66 

0 PPm 50 PPm 250 ppm 500 ppm 

Hematology 

n 

Male 

Nucleated erythrocytes (103/bL) 

Eosinophils (103/&L) 

Monocytes (103/pL) 

Lymphocytes (103/bL) 

Segmented neutrophils (103/bL) 

Leukocytes (103/bL) 

Reticulocyta (106/pL) 

Mean cell hemoglobin concentration (g/dL) 

Mean cell hemoglobin (pg) 

Mean cell volume (a) Erythrocytes (lO'/bL) 

Hemoglobin (g/dL) 

Hematocrit (%) 

Clinical Chemistry 

Aspartate aminotransferase (IUL) 

Alanine aminotransferase (IUL) 

Creatinine (mg/dL) 

Urea nitrogen (mg/dL) 

y-glutamyltransferase (IUL) 

Hematology 

n 

Female 

Nucleated erythrocytes (103/bL) 

Eosinophils (l#/fiL) 

Monocytes (103/pL) 

Lymphocytes (103/bL) 

Segmented neutrophils (ld/bL) 

Leukocytes (l$/bL) 

Reticulocytes (106/pL) 

Mean cell hemoglbbin concentration (g/dL) 

Mean cell hemoglobin (pg) 

Mean cell volume (fL) 

Erythrocytes (106/bL) 

Hemoglobin (g/dL) 

Hematocrit (%) 

Clinical Chemistry 

Aspartate aminotransferase (IUL) 

Alanine aminotransferase (IUL) 

Creatinine (mg/dL) 

Urea nitrogen (mg/dL) 

y-glutamyltransferase (IUL) 

10 

36.3 f 0.3 

17.4 f 0.3 

41.9 f 0.8 

8.95 f 0.23 

15.5 f 0.3 

42.7 f 0.9 

0.00 f 0.00 

0.04 f 0.01 

0.10 f 0.02 

3.05 f 0.17 

0.94 f 0.13 

4.13 f 0.22 

0.2 f 0.0 

0.34 f 0.05d 

24.4 f 1.1c 

1.1 & 0.7b 

141 f ZOb 

185 f Db 

10 

35.8 & 1.0 

17.0 f 0.3 

47.8 f 0.8 

9.39 f 0.13 

16.0 f 0.3 

44.8 * 0.8 

0.01 f 0.01 

0.06 f 0.02 

0.10 f 0.02 

3.16 f 0.37 

0.86 f 0.15 

4.19 f 0.46 

0.3 & 0.0 

0.29 f OMb 

21.5 f 2.0 

1.2 f 1.1 

174 * 37 

85 f 21 

10 

35.7 f 0.5 

17.0 f 0.2 

47.8 f 0.3 

9.30 f 0.05 

15.8 f 0.2 

44.3 f 0.4 

0.00 f 0.00 

0.05 f 0.02 

0.08 f 0.03 

3.98 f 0.37 

0.91 f 0.07 

5.02 f 0.42 

0.2 f 0.0 

134 f 16 

189 f 28 

0.36 rf: 0.04 

25.8 f 0.8 

0.2 f 0.1 

10 

36.0 f 0.5 

17.1 f 0.2 

47.6 f 0.3 

9.33 f 0.13 

16.0 f 0.2 

44.4 f 0.7 

0.00 f 0.00 

0.04 f 0.02 

0.14 f 0.04 

2.86 f 0.21 

0.68 rf: 0.08 

3.72 f 0.32 

0.3 f 0.0 

125 f 11 

129 f 28 

0.30 f OMb 

23.1 f 1.8 

0.9 * 0.6 

10 

35.4 f 0.6 

16.9 f 0.2 

47.8 f 0.4 

9.19 f 0.18 

15.5 f 0.1 

44.0 & 1.1 

0.00 f 0.00 

0.06 f 0.01 

0.09 f 0.02 

3.17 f 0.15 

0.91 rf: 0.11 

4.23 f 0.18 

0.2 f 0.0 

111 f llb 

164 f 16b 

0.33 f 0.06' 

24.0 f 0.9 

0.6 f 0.3 

10 

37.4 f 0.6 

17.7 f 0.4 

47.3 f 0.4 

9.17 f 0.15 

16.2 f 0.2 

43.4 f 0.5 

0.00 f 0.00 

0.05 f 0.01 

0.08 f 0.02 

2.94 f 0.38 

0.70 f 0.10 

3.77 f 0.42 

0.2 f 0.0 

98 f 27 

0.31 f OMb 

22.7 f l.Zb 

0.0 f 0.ob 

141 f 

9 

36.0 f 0.8 

17.1 f 0.3 

47.7 f 0.5 

9.36 f 0.16 

16.0 f 0.2 

44.6 f 1.1 

0.01 f 0.01 

0.03 k 0.02 

0.08 If: 0.02 

3.45 f 0.28 

0.86 f 0.13 

4.42 f 0.33 

0.2 f 0.0 

165 f 37e 

252 +. 4tle 

0.46 f O.lZd 

24.9 k 0.9' , , 

0.6 f 0.4 

10 

35.7 f 0.6 

16.9 f 0.2 

47.5 f 0.6 

9.54 f 0.18 

16.1 f 0.2 

45.3 f 1.0 

0.00 f 0.00 

0.06 f 0.02 

0.10 f 0.02 

3.55 f 0.44 

0.71 f 0.07 

4.42 f 0.50 

0.3 f 0.0 ' 

0.26 rf: 0.04 

25.7 f 1.6 

0.0 f 0.0 

96 f 11 

56 f 9 

* Mean * standard error 

n=9 ' n=7 n=5 e n=8 
Methylphenidate Hydrochloride, NTP TR 439 
261 

SPECIAL STUDIES 

APPENDIX H 

TABLE H2 Bone Length and Bone Density in Rats in the 13-Week Feed Study 

TABLE H1 Nose-to-Rump Length in Rats in the 13-Week Feed Study 

METHODS............................................ ......................... 

264 

263 

262 

of Methylphenidate Hydrochloride 

of Methylphenidate Hydrochloride ......................................... 

......................................... 
262 Methylphenidate Hydrochloride, NTP TR 439 

SPECIAL STUDIES 

initiation, and on all surviving rats at approximately 4, 8, and 13 weeks into the study. 

For the 13-week studies, nose-to-rump length measurements were taken on all rats prior to study 

Nose-to-Rump Length in the 13-Week Studies 

METHODS 

one-half centimeter. 

bar, and the tail was pulled. The nose-to-rump length at the base of the tail was recorded to the nearest 

A stationary bar was positioned at the 0.5 centimeter mark of a rule, the rat’s teeth were engaged to the 

length or density, the femurs were manually cleared of extraneous tissue. 

determine bone length; the left femur was used to determine bone density. Prior to measurement of bone 

Both femurs of all surviving rats were removed at terminal sacrifice. The right femur was used to 

Bone Length and Density in the 13-Week Studies 

Bone length was measured to the nearest millimeter as the shortest distance between opposing epiphyses. 

difference between weight of the bone in air and weight of the bone in water. 

and pressure method, where the density of the bone (g/mL) is the weight of the bone in air divided by the 

same stainless steel wires, and measured again. Bone density was calculated using a standard temperature 

Balance (Mettler Instrument Corporation). The bones were then blotted dry, suspended in air from the 

wire. While suspended, the weights of the bones were measured to the nearest 0.001 gram with a Mettler 

temperature for 1 hour. The bones were then rinsed and suspended in distilled water by a stainless steel 

Prior to measurement of bone density, left femurs were rehydrated in 0.85% sodium chloride at room 
Special Studies 263 

Nose-to-Rump Length in Rats In the 13-Week Feed Study of Methylphenidate Hydrochloridea 

TABLE H1 

n 10 

13 Weeks 

8 Weeks 

4 weeks 

Study initiation 

Male 

23.75 f 0.20 

22.55 f 0.12 

20.55 f 0.19 

15.40 f 0.16 

13 Weeks 

8 Weeks 

4 weeks 

Study initiation 

Female 

21.45 f 0.09 

21.35 f 0.13 

18.65 f 0.11 

14.65 f 0.11 

10 

23.50 f 0.19b 

22.44 f 0.18b 

20.45 f 0.09 

15.25 f 0.13 

21.43 f 0.13‘ 

21.35 f 0.18 

18.75 f 0.13 

14.55 f 0.09 

10 

23.44 f 0.21b 

22.70 f 0.19 

20.75 f 0.19 

15.40 f 0.15 

21.40 f 0.10 

21.30 f 0.13 

18.65 f 0.11 

14.50 0.11 

10 

15.45 f 0.16 

20.45 f 0.20 

22.35 f 0.11 

23.50 f 0.20 

21.70 f 0.15 

21.60 f 0.19 

18.80 f 0.19 

14.80 f 0.11 

10 

23.60 f 0.15 

22.40 f 0.10 

20.60 f 0.18 

15.30 f 0.17 

14.75 f 0.08 

21.75 f 0.17 

21.65 f 0.17 

18.65 f 0.13 

10 

23.10 f 0.15 

22.20 f 0.13 

20.05 f 0.14 

15.45 f 0.14 

21.65 & 0.08 

21.40 f 0.12 

18.55 f 0.14 

14.60 f 0.12 

a Data are presented as mean f standard error. Nose-to-rump lengths are measured in centimeters. Differences from the control 

’ n=7 

n=9 

are not significant by Williams’ or Dunnett’s test. 
264 Methylphenidate Hydrochloride, NTP TR 439 

2,Ooo PPm 

Bone Length and Bone Density in Rats in the 13-Week Feed Study of Methylphenidate Hydrochloridea 

TABLE H2 

0 PPm 125 ppm 250 ppm 500 PPm 1,000 ppm 

n 10 10 10 10 10 10 

Male 

Bone density 

Bone length .. 

38.50 f 0.27 38.25 f 0.70b 38.63 f 0.32b 38.70 & 0.33 39.60 f 0.31. 39.20' f 0.44 

1.32 f 0.01 1.32 f 0.01' 1.29 f 0.02' 1.31 f 0.01 1.34 f 0.01 . 1.30 f 0.02 

Female 

Bone density 

Bone length 

35.50 f 0.50 33.57 f 0.95 35.2O.f 0.51 . 35.50 f 0.56 35.60 f 0.54 ' 35.50 f 0.62 

1.32 f 0.02 i.30 f 0.01~ 1.30 f 0.01 1.29 f 0.01 . 1.31 f 0.01 1.29 f 0.02 

in millimeters. 

Significantly different (P=O.O5) from the control by Shirley's test 

a Data are presented as mean f standard error. Bone density is. measured in grams per cubic centimeter; bone length is measured 

n=8 ' 

n=7 

' n=9 
265 

APPENDIX I 

CHEMICAL CHARACTERIZATION 

AND DOSE FORMULATIONS 

TABLE I1 Preparation and Storage of Dose Formulations in the Feed Studies 

FIGURE I2 Nuclear Magnetic Resonance Spectrum of Methylphenidate Hydrochloride . . . . . . . . . . 269 

ETCURE I1 Infrared Absorption Spectrum of Methylphenidate Hydrochloride . . . . . . . . . . . . . . . . . 268 

PREPARATION AND ANALYSIS OF DOSE FORMULATIONS . . . . . . . . . . . . . . . . . l . . . . . . . . . . . . . . . . . . 267 

PROCUREMENT AND CHARACTERIZATION OF M~HYLPHENIDATE HYDROCHL~RIDE . . . . . . . . . . . . . . , . 266 

in the 13-Week and 2-Year Feed Studies of Methylphenidate Hydrochloride . . . . . . . . . . 278 

TABLE I5 Results of Referee Analysis of Dose Formulations Administered to Rats and Mice 

in the 2-Year Feed Studies of Methylphenidate Hydrochloride . . . . . . . . . . . . . . . . . . . . 273 

TABLE I4 Results of Analysis of Dose Formulations Administered to Rats and Mice 

in the 13-Week Feed Studies of Methylphenidate Hydrochloride . . . . . . . . . . . . . . . . . . . 272 

TABLE I3 Results of Analysis of Dose Formulations Administered to Rats and Mice 

in the 14-Day Feed Studies of Methylphenidate Hydrochloride . , . . . . . . . . . . . . . . . . . . 271 

TABLE I2 Results of Analysis of Dose Formulations Administered to Rats and Mice 

of Methylphenidate Hydrochloride , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 270 
266 Methylphenidate Hydrochloride, NTP TR 439 

CHEMICAL CHARACTERIZATION AND 

DOSE FORMULATIONS STUDIES 

at the National Institute of Environmental Health Sciences. 

MO). Reports on analyses performed in support of the methylphenidate hydrochloride studies are on file 

analyses were conducted by the analytical chemistry laboratory, Midwest Research Institute (Kansas City, 

week studies. Lot CMS86-166-001 was used throughout the 2-year studies. Identity, purity, and stability 

Ciba-Geigy Corporation (Summit, NJ) in two lots. Lot M1088 was used throughout the 14-day and 13- 

United States Pharmacopeia (USP) grade methylphenidate hydrochloride (rhreo racemate) was supplied by 

METHYLPHENIDATE HYDROCHLORIDE 

PROCUREMENT AND CHARACTERIZATION OF 

spectra are presented in Figures I1 and 12. No optical activity was detected. 

(Sudrler Standard Spectra) of methylphenidate hydrochloride. The infrared and nuclear magnetic resonance 

with the structure and the infrared and ultraviolet spectra were consistent with the literature spectra 

by infrared, ultraviolet/visible, and nuclear magnetic resonance spectroscopy. All spectra were consistent 

Both lots of the chemical, a white, fine crystalline solid, were identified as methylphenidate hydrochloride 

potassium dihydrogen ph0sphate:acetonitrile (70:30) was used. 

performed using the HPLC system previously described, except a solvent system of 0.02 M aqueous 

ne flow rate was 1.0 mL/minute. A concomitant analysis of lot M1088 with lot CMS86-166-001 was 

(205 nm) and a solvent system of 0.02 M aqueous potassium dihydrogen ph0sphate:acetonitrile (8218). 

ultraviolet light. HPLC was performed with a Waters pBondapak C,, column using ultraviolet detection 

examined under 254 nm ultraviolet light after being air-dried and exposed overnight to longwave (366 nm) 

reference standard used was a-phenyl-2-piperidineacetic acid hydrochloride (USP grade). Plates were 

Gel 60 F-254 plates using a solvent system of ch1oroform:methanol:glacial acetic acid (65:25:5). The 

To determine the level of a-phenyl-2-piperidineacetic acid hydrochloride, TLC was performed on Silica 

ordinary light after being air-dried and sprayed with Dragendorffs reagent, followed by 1 N sulfuric acid. 

hydrochloride eryrhro isomer (USP grade) was used as a reference standard. Plates were examined under 

eryrhro (dl) isomer, TLC was performed using system 1 with a solvent ratio of 95:5:0.5. Methylphenidate 

hydrochloride (cO.6%), USP thin-layer chromatography methods were used. To determine the level of the 

specifications, for two impurities, the erythro (44 isomer (~1%) and a-phenyl-2-piperidineacetic acid 

Dragendorffs reagent, followed by 1 N sulfuric acid. To confirm conformance with USP purity 

standard. Plates were examined under shortwave (254 nm) ultraviolet light and after spraying with 

(9550.5) and 2) n-butano1:water:glacial acetic acid (6617:17). Nicotinamide was used as a reference 

60 F-254 plates using two solvent systems: 1) ch1oroform:methanol:concentrated ammonium hydroxide . 

with aqueous 4 M potassium chloride electrolyte. Thin-layer chromatography was performed on Silica Gel 

0.1 N perchloric acid and monitored potentiometrically using a micro combination pH/mV electrode filled 

glacial acetic acid and adding mercuric acetate test solution. The sample solutions were then titrated with 

Titration of the amine group was performed by dissolving samples of methylphenidate hydrochloride in 

amine group, thin-layer chromatography ("LC), and high-performance liquid chromatography (HPLC). 

The purity of each lot was determined by elemental analyses, Karl Fischer water analysis, titration of the 

with areas greater than 0.1% of the major peak area. A major peak comparison with a USP standard 

a-phenyl-2-piperidineacetic acid hydrochloride content. HPLC revealed a major peak and no impurities 

major spot. United States Pharmacopeia purity "LC indicated no eryrhro isomer was present and 0.2% 

layer chromatography by system 1 indicated a major spot and one trace impurity, and system 2 indicated a 

indicated 0.05 f 0.01% water. Titration of the amine group indicated a purity of 100.0 rl: 0.6%. Thinagreement with the theoretical values for methylphenidate hydrochloride. Karl Fischer water analysis 

For lot M1088, elemental analyses of the chemical for carbon, hydrogen, nitrogen, and chlorine were in 
Chemical Characterization and Dose Formulations 267 

overall purity was determined to be greater than 99% and was consistent with USP purity specifications. 

solution indicated that the bulk chemical had a purity of 99.4 f 0.7% relative to the USP standard. The 

to lot M1088. The qverall purity of lot CMS86-166-001 was determined to be greater than 99%. 

Based on the results of the concomitant analysis, lot CMS86-166-001 had a purity of 100.0 f 1.5% relative 

HPLC indicated a major peak and no impurities with areas greater than 0.1% of the major peak area. 

a-phenyl-2-piperidineacetic acid hydrochloride was present at a level above USP purity specifications. 

major spot. United States Pharmacopeia purity TLC indicated that neither the erythro isomer nor 

amine group indicated a purity of 100.5 f 0.3%. Thin-layer chromatography by both systems indicated a 

carbon was slightly high. Karl Fischer water analysis indicated 0.086 -c 0.004% water. Titration of the 

agreement with the theoretical values for methylphenidate hydrochloride. The elemental analysis for 

For lot CMS86-166-001, elemental analyses of the chemiial for hydrogen, nitrogen, and chlorine were in 

the bulk chemical was detected. 

was monitored during the 2-year studies using HPLC and titration of the amine group. No degradation of 

stored at 20" to 24" C in plastic bags inside metal pails which were placed in a ventilated cabinet. Stability 

when stored protected from light at temperatures up to 60" C. To ensure stability, the bulk chemical was 

These studies indicated that methylphenidate hydrochloride was stable as a bulk chemical for 2 weeks 

performed using the system described for the purity analysis, except a solvent ratio of 70:30 was used. 

Stability studies of the bulk chemical were performed by the analytical chemistry laboratory. HPLC was 

for the initial five minutes. Formulations were stored in double plastic bags at 4" C for up to 2 weeks. 

was then blended with feed in a Patterson-Kelly twin-shell blender for 15 minutes using an intensifier bar 

(Table 11). Mixtures were made by preparing a methylphenidate hydrochloride/feed premix by hand, which 

The dose formulations were prepared weekly by mixing methylphenidate hydrochloride with feed 

PREPARATION AND ANALYSIS OF DOSE FORMULATIONS 

and light (simulated animal cage conditions). 

confirmed for at least 3 weeks at 5" C when stored in the dark, and for up to 7 days when exposed to air 

performed using HPLC. Homogeneity was confirmed and the stability of the dose formulation was 

(68:32). The flow rate was 1.0 mL/minute. Stability studies of the 200 ppm formulation were also 

detection (205 nm) and a solvent system of 0.02 M aqueous potassium dihydrogen ph0sphate:acetonitrile 

dihydrogen phosphate. HPLC was performed with a Waters pBondapak C,, column using ultraviolet 

standard, acetophenone in acetonitrile (0.1 mg/mL), then diluted with 0.020 M aqueous potassium 

concentrated hydrochloric acid and centrifuged. Aliquots of the extract were mixed with an internal 

the analytical chemistry laboratory. Aliquots were extracted with acetonitrile containing 0.85% 

Homogeneity studies of a mixture of 200 ppm methylphenidate hydrochloride in feed were performed by 

(Table 15). 

performed by the analytical chemistry laboratory agreed with the results obtained by the study laboratory 

mixture differing by more than 21% from the target concentration. Results of periodic referee analyses 

analyzed during the 2-year studies, 88% (146/167) were within 10% of the target concentration, with no 

formulations were analyzed initially and then every 6 to 10 weeks (Table 14). Of the dose formulations 

90% (18/20) were within 10% of the target concentration. During the 2-year studies, the dose 

studies, dose formulations were analyzed at the beginning, midpoint, and end of the studies (Table 13); 

formulation was analyzed (Table 12); all were within 10% of the target concentration. For the 13-week 

laboratory and analytical chemistry laboratory using HPLC. During the 14-day studies, only the initial 

Periodic analyses of the dose formulations of methylphenidate hydrochloride were conducted at the study 
MICROMETERS 

f 60 

40 - 

20 - 

H II 

0 

01 I I I I I I 

WAVENUMBER (CM-') 

I I I I I I 

4000 3500 3000 2500 2000 1800 1600 1400 ,1200 1000 800 600 400 21 

ABSCISSA 

SAMPLE:MRI No.: 127N 

SUPPRESSION Off 

EXPANSION 1 

Batch No.: 02 

Methylphenidate Hydrochloride 

~- 

Prniart Nn . RAnl .fifi 

Lot NO.: CMS86-166-001 

ORDINATE 

RESPONSE 1 TIME DRIVEL PRE SAMPLE CHOP-:. 

SCAN TIME 12 min REP. SCAN A SINGLE BEAM - 

EXPANSION 1 

I I 
269 

4: 'F W 

z 

E- f 

lW 

-I 

3 

4 

Nuclear Magnetic Resonance Spectrum of Methylphenidate Hydrochloride 

FIGURE I2 
270 Methylphenidate Hydrochloride, NTP TR 439 

Hydrochloride 

Preparation and Storage of Dose Formulations in the Feed Studies of Methylphenidate 

TABLE I1 

14-Day Studies 13-Week Studies 2-Year Studies 

Doses were prepared weekly. 

5 minutes and off for 10 minutes. 

with the intensifier bar on for 

Patterson-Kelly twin-shell blender 

remaining feed and blended in a 

prepared, then layered into the 

methylphenidate hydrochloride was 

A premix of feed and 

Preparation 

Same as 14day studies 

M1088 

Chemical Lot Number 

2 weeks 

Maximum Storage Time 

M1088 

2 weeks 

Stored in double plastic bags at 4" C Same as 14-day studies 

Storage Conditions 

(Madison, WI) 

Hazleton Laboratories America, Inc. Same as 14day studies 

Study Laboratory 

Referee Laboratory 

Same as 14day studies 

CMS86-166-001 

2 weeks 

Same as 14day studies 

(Worcester, MA) 

"XI Mason Research Institute 

Kansas City, MO 

Midwest Research Institute, Same as 14-day studies Same as 14day studies 
Chemical Characterization and Dose Formulations 

of Methylphenidate Hydrochloride 

Results of Analysis of Dose Formulations Administered to Rats and Mice in the 14-Day Feed Studies 

TABLE I2 

271 

Date Prepared Date Analyzed Concentration Concentrationa from Target 

Target Determined % Difference 

8 June 1983 8 June 1983 

250 

62 

16 

4,0oo 

1,000 

59.0 

14.8 

4,010 

952 

254 

-5 

+2 

-5 

-8 

0 

a Results of duplicate analyses 
272 Methylphenidate Hydrochloride, NTP TR 439 

of Methylphenidate Hydrochloride 

Results of Analysis of Dose Formulations Administered to Rats and Mice in the 13-Week Feed Studies 

TABLE I3 

(PP@ 

Date Prepared Date Analyzed Concentration concentration' from Target 

Target Determined % Difference 

(PP@ 

6 October 1983 7-9 October 1983 

500 

250 

125 

2,000 

1,OOO 

1 December 1983 1-2 December 1983 

500 

250 

125 

2,OoO 

1,OoO 

2,000 

1,000 

500 

1 January 1984 250 

30 December 1983 30 December 1983 - 125 

508 

247 

142 

2,120 

1,055 

508 

236 

121 

2,015 

1,035 

976 

507 

252 

157 

2,035 

+6 

+6 

-1 

+ 14 

+2 3 

+1 

+4 

+2 

-6 

-3 

+2 

-2 

+1 

+1 

+26 

30 December 1983b 5-6 January 1984 

30 December 1983' 5-6 January 1984 125 

125 

98 

110 

-21 

-1 2 

5 January 1984 5-6 January 1984 

500 

250 

125 

1,ooo 992 

532 

264 

130 

1,995 

-1 

+6 

+6 

+4 

0 

a Results of duplicate analyses 

Test diet mixed on 30 December 1984 and diluted with basal diet on 3 January 1985 and remixed prior to feeding to animals. 

Results of remix 
Chemical Characterization and Dose Formulations 273 

of Methylphenidate Hydrochloride 

Results of Analysis of Dose Formulations Administered to Rats and Mice in the 2-Year Feed Studies 

TABLE I4 

(PPW 

Date Prepared Date Analyzed Concentration concentration' from Target 

Target Determined % Difference 

(PPm) 

Rats 

15 July 1986 21 July 1986 

950d 

979c 

957b 

-5 

-2 

-4 

13 August 1986 15 August 1986 

500 

500 

100 

100 

1,000 

1,000 

925 

903 

456 

464 

89 

96 

-8 

-10 

-9 

-7 

-1 1 

-4 

16 September 1986 18 September 1986 

500 

500 

100 

1 ,@)o 904 

498 

499 

92 

0 

0 

-8 

-1 0 

11 November 1986 12 November 1986 

500 

500 

500 

100 

100 

1,000 

1,000 922 

492 

482 

456 

105 

104 

1,080 +8 

-8 

-2 

-4 

-9 

+5 

+4 

12 January 1987 13 January 1987 

500 

500 

100 

1,000 

509 

488 

106 

1,001 

+2 

-2 

+6 

0 

2 March 1987 4 March 1987 

500 

500 

100 

1.000 803 

431 

453 

79 

-20 

-1 4 

-9 

-21 

9 March 1987e 

27 April 1987 

9 March 1987 

27 April 1987 

1,O00 

500 

100 

941 

476 

99 

-6 

-5 

-1 

832 

830 

869 

409 

412 

410 

96 

91 

96 

-17 

-17 

-13 

-18 

-1 8 

-1 8 

-4 

-9 

-4 
274 Methylphenidate Hydrochloride, NTP TR 439 

of Methylphenidate Hydrochloride (continued) 

Results of Analysis of Dose Formulations Administered to Rats and Mice in the 2-Year Feed Studies 

TABLE I4 

(PPm) 

Date Prepared Date Analyzed Concentration Concentration' from Target 

.Target Determined % Difference 

(PPd 

Rats (continued) 

4 May 1987e 4 May 1987 

500 

500 

500 

500 

1,000 

1,000 

507b 

480' 

505 

966 

969 

477d 

-3 

-3 

-5 

+1 

-4 

+1 

22June1987 23 June 1987 

500 

500 

100 

1,000 944 

454 

430 

88 

-6 

-9 

-14 

-12 

24 June 1987e 25June1987 

500 

100 

434 

92 

-13 

-8 

17 August 1987 

29 June 1987e 500 474 -5 

17 August 1987 

29June1987 

500 

500 

500 

100 

100 

1 ;Ooo 

1,000 

983 

994 

484 

486 

496 

101 

96 

-2 

-1 

-3 

-3 

-1 

+1 

-4 

12 October 1987 12 October 1987 

500 

500 

500 

100 

100 

1,000 

1,000 

995 

989 

505 

496 

499 

106 

98 

-1 

-1 

+1 

-1 

0 

+6 

-2 

7 December 1987 7 December 1987 

500 

500 

500 

100 

100 

1,000 

1,000 

503 

501 

494 

102 

99 

1,000 

1,025 

-1 

+2 

0 

+3 

+1 

0 

-1 

1 February 1988 1 February 1988 

500 

500 

500 

100 

100 

1,000 

1,000 970 

487 

487 

490 

96 

94 

1,004 

-3 

-3 

-3 

-2 

-4 

4 

0 
Chemical Characterization and Dose Formulations 275 

of Methylphenidate Hydrochloride (continued) 

Results of Analysis of Dose Formulations Administered to Rats and Mice in the 2-Year Feed Studies 

TABLE I4 

Target Determined % Difference 

Date Prepared Date Analyzed Concentration concentration' from Target 

(PP4 (PP@ 

28 March 1988 

Rats (continued) 

28 March 1988 

500 

500 

100 

1,000 

501 

500 

92 

1,030 +3 

0 

0 

-8 

23 May 1988 23 May 1988 

500 

500 

500 

100 

100 

1,000 

1,000 

993 

993 

508 

492 

511 

96 

94 

-1 

-1 

+2 

-2 

+2 

4 

-6 

1 August 1988 1 August 1988 

500 

500 

100 

100 

1,000 

1,000 

981 

955 

514 

497 

99 

96 

-2 

-5 

-1 

+3 

-1 

-4 

Mice 

15 July 1986 23 July 1986 

49.3 

51' 

46b 

50 

50 

50 

-2 

+2 

-8 

500 

250 

50 

481 

275 

53 

-4 

+10 

23 July 1986 24 July 1986 +6 

16 September 1986 18 September 1986 

500 

500 

250 

50 

498 

499 

258 

52 

0 

0 

+3 

+4 

11 November 1986 12 November 1986 

500 

500 

500 

250 

50 

492 

482 

456 

252 

54 

-2 

-4 

-9 

+1 

+8 

509 

488 

254 

12 January 1987 13 January 1987 52 

500 

500 

250 

50 

+2 

-2 

+2 

+4 
276 Methylphenidate Hydrochloride, NTP TR 439 

of Methylphenidate Hydrochloride (continued) 

Results of Analysis of Dose Formulations Administered to Rats and Mice in the 2-Year Feed Studies 

TABLE I4 

(PP@ 

Date Prepared Date Analyzed Concentration Concentrationa from Target 

Target Determined % Difference 

(PPm) 

Mice (continued) 

2 March 1987 4 March 1987 

500 

500 

250 

50 

431 

453 

218 

46 

-14 

-9 

-13 

-8 

9 March 1987e 9 March 1987 

27 April 1987 27 April 1987 

500 

250 

476 

253 

-5 

+l 

500 

500 

500 

250 

50 

409 

412 

410 

217 

50 

-18 

-18 

-18 

-13 

0 

4 May 1987e 4 May 1987 

477d 

507b 

480' 

505 

232 

-5 

+1 

-4 

+l 

-7 

500 

500 

500 

500 

250 

454 

430 

246 

46 

-9 ' 

-14 

-2 

22June1987 23 June1987 -8 

500 

500 

250 

50 

17 August 1987 

29 June 1987e 

24 June 1987e 

17 August 1987 

29June1987 

25 June 1987 500 434 -13 

500 474 -5 

484 

486 

496 

260 

47 

-3 

-3 

-1 

+4 

-6 

500 

500 

500 

250 

50 

12 October 1987 12 October 1987 

505 

496 

499 

250 

53 

+1 

-1 

0 

0 

+6 

500 

500 

500 

250 

50 

503 

501 

494 

253 

51 

-1 

+1 

+2 

+1 

0 

7 December 1987 7 December 1987 

500 

500 

500 

250 

50 
Chemical Characterization and Dose Formulations 277 

of Methylphenidate Hydrochloride (continued) 

Results of Analysis of Dose Formulations Administered to Rats and Mice in the 2-Year Feed Studies 

TABLE I4 

(PPm) 

Date Prepared Date Analyzed Concentration Concentration' from Target 

Target Determined % Difference 

(PPd 

Mice (continued) 

1 February 1988 1 February 1988 

500 

500 

500 

250 

50 

28 March 1988 28 March 1988 

23 May 1988 23 May 1988 

1 August 1988 1 August 1988 

500 

500 

250 

50 

500 

500 

500 

250 

50 

500 

500 

487 

487 

490 

240 

49 

501 

500 

251 

50 

508 

492 

511 

245 

47 

514 

497 

-3 

-3 

-2 

-4 

-2 

+2 

-2 

+2 

-2 

-6 

-1 

+3 

' Results of duplicate analyses 

Sample selection from bottom of twin-shell blender 

Sample selection from top right of twin-shell blender 

Sample selection from top left of twin-shell blender 

e Results of remix 
278 Methylphenidate Hydrochloride, NTP TR 439 

2-Year Feed Studies of Methylphenidate Hydrochloride 

Results of Referee Analysis of Dose Formulations Administered to Rats and Mice in the 13-Week and 

TABLE I5 

Date Prepared 

Determined Concentration hpm) 

Target Concentration Study RePeree 

(PP@ Laboratorp Laboratoryb 

13-Week Studies (Hazleton Laboratories America, Inc) 

5 January 1984 

3 January 1984 

30 December 1983 

125 

125 

125 

2-Year Studies (TSI Mason Research Institute) 

Rats 

7 December 1987 

27 April 1987 

2 March 1987 

12 January 1987 

Mice 

22June1987 

23 July 1986 

50 

250 

130 

98 

130 

125 * 5 

101.6 f 8.4 

125 f 2 

99 

830 

803 

1,001 

97.6 2 1.8 

823 f 1 

758 f 27 

935 f 9 

46 

275 

48.6 f 0.8 

243 f 2 

a Results of duplicate analyses 

Results of triplicate analyses (mean f standard error) 
279 

IN THE 2-YEAR FEED STUDIES 

FEED AND COMPOUND CONSUMPTION 

APPENDIX J 

TABLE J1 Feed and Compound Consumption by Male Rats in the 2-Year Feed Study 

TABLE J2 Feed and Compound Consumption by Female Rats in the 2-Year Feed Study 

TABLE 53 Feed and Compound Consumption by Male Mice in the 2-Year Feed Study 

TABLE 54 Feed and Compound Consumption by Female Mice in the 2-Year Feed .Study 

of Methylphenidate Hydrochloride 

of Methylphenidate Hydrochloride 

of Methylphenidate Hydrochloride 

of Methylphenidate Hydrochloride ....................................... 

283 

282 

281 

280 

....................................... 

....................................... 

....................................... 
280 Methylphenidate Hydrochloride, NTP TR 439 

of Methylphenidate Hydrochloride 

Feed and Compound Consumption by Male Rats in the 2-Year Feed Study 

TABLE J1 

104 

101 

97 

93 

89 

85 

81 

77 

73 

69 

65 

62 

56 

53 

49 

45 

41 

37 

33 

29 

25 

21 

16 

12 

9 

5 

2 

14.4 

14.5 

13.5 

14.7 

14.8 

15.2 

15.8 

18.1 

20.4 

16.7 

16.4 

17.4 

17.1 

17.6 

16.5 

16.4 

16.6 

17.6 

18.2 

16.0 

15.8 

17.1 

19.0 

16.1 

16.4 

14.8 

13.6 

53-104 . 16.2 

14-52 17.0 

1-13 15.2

Mean for weeks 

150 13.6 

215 15.5 

271 16.8 

314 16.8 

336 16.1 

362 16.9 

372 16.0 

387 16.5 

391 18.7 

399 18.0 

396 16.0 

407 16.0 

405 16.2 

419 17.3 

415 16.3 

421 18.2 

420 16.4 

424 17.0 

431 20.8 

427 17.5 

423 15.8 

426 15.1 

425 15.0 

414 15.0 

410 14.3 

400 14.4 

391 15.1 

238 15.7 

384 16.7 

418 16.3 

150 9 

220 7 

273 6 

315 5 

337 5 

362 5 

370 4 

389 4 

397 5 

407 4 

403 4 

413 4 

412 4 

425 4 

423 4 

428 4 

430 4 

433 4 

441 5 

430 4 

427 4 

429 4 

432 4 

423 4 

417 3 

41 1 4 

400 4 

239 7 

388 4 

425 4 

13.7 

13.1 

13.9 

14.2 

15.1 

15.7 

15.4 

16.8 

21 .o 

16.4 

16.1 

18.6 

15.7 

17.8 

16.9 

15.6 

16.2 

17.5 

19.0 

15.9 

15.8 

17.6 

15.7 

16.9 

17.0 

15.0 

13.0 

16.0 

16.7 

15.5 

372 

378 

389 

393 

398 

404 

395 

397 

398 

393 

395 

395 

385 

394 

379 

384 

381 

380 

380 

374 

362 

358 

332 

314 

274 

211 

147 

392 

370 

237 

18 

17 

18 

18 

19 

19 

20 

21 

26 

21 

20 

24 

20 

23 

22 

20 

21 

23 

25 

21 

22 

25 

24 

27 

31 

36 

44 

20 

23 

34 

15.9 

17.5 

17.2 

15.6 

17.7 

17.4 

15.3 

12.7 

13.6 

13.8 

14.4 

14.5 

15.5 

15.2 

16.2 

16.2 

20.3 

16.7 

16.7 

18.5 

16.1 

17.4 

16.7 

15.7 

16.6 

17.9 

' 17.7 

16.1 

16.8 

15.8 

353 

364 

367 

373 

384 

385 

393 

388 

397 

391 

389 

391 

387 

388 

376 

382 

379 

380 

373 

366 

352 

348 

323 

310 

269 

211 

145 

382 

364 

234 

39 

38 

39 

39 

41 

40 

41 

42 

51 

43 

43 

47 

42 

45 

45 

41 

44 

47 

47 

44 

50 

49 

48 

57 

65 

73 

88 

42 

46 

71 

a Grams of feed consumed per animal per day. 

Milligrams of methylphenidate hydrochloride consumed per kilogram body weight per day. 

1 
Feed and Compound Consumption 281 

of Methylphenidate Hydrochloride 

Feed and Compound Consumption by Female Rats in the 2-Year Feed Study 

TABLE 52 

86 

82 

78 

74 

69 

62 

58 

54 

50 

46 

42 

39 

34 

30 

26 

22 

17 

13 

10 

6 

2 

105 

102 

98 

94 

.90 

12.3 

12.2 

12.4 

11.0 

11.2 

12.0 

13.2 

13.1 

12.6 

12.1 

12.0 

11.4 

12.7 

11.3 

12.0 

12.2 

10.7 

11.0 

12.0 

10.8 

10.0 

10.8 

10.2 

11.6 

10.9 

11.0 

53-105 12.2 

14-52 11.2 

1-13 10.9

Mean for weeb 

122 10.7 

156 10.7 

184 11.6 

197 10.7 

207 11.0 

21 1 10.2 

21 5 11.1 

225 12.1 

233 11.3 

238 11.1 

244 11.6 

252 11.3 

256 11.6 

265 11.8 

271 12.4 

281 12.6 

297 13.7 

308 14.2 

312 13.3 

324 12.5 

326 12.1 

325 11.3 

314 11.9 

326 11.5 

315 11.1 

317 10.5 

165 10.9 

231 11.3 

306 12.2 

302 

301 

310 

314 

320 

316 

313 

305 

298 

286 

271 

256 

257 

246 

240 

234 

230 

226 

221 

210 

206 

203 

193 

178 

150 

121 

296 

224 

160 

4 

4 

4 

4 

4 

4 

4 

4 

5 

5 

5 

5 

5 

5 

5 

5 

5 

5 

6 

5 

5 

5 

6 

7 

7 

9 

4 

5 

7 

10.7 

10.8 

11.8 

11.6 

10.1 

11.0 

11.2 

11.2 

11.8 

11.9 

12.1 

12.4 

12.2 

13.3 

14.1 

10.3 

11.7 

10.9 

11.1 

10.7 

11.4 

10.4 

11.3 

12.0 

10.7 

9.8 

11.9 

10.9 

11.1 

276 

280 

290 

290 

293 

288 

282 

273 

266 

257 

243 

237 

235 

230 

222 

227 

221 

218 

21 5 

207 

204 

202 

192 

177 

154 

117 

270 

216 

160 

43 9.6 

38 10.5 

33 11.5 

28 10.9 

27 10.7 

24 10.1 

26 10.9 

28 10.9 

26 10.4 

24 10.8 

25 10.8 

24 10.7 

24 10.8 

23 10.8 

25 10.4 

21 10.3 

28 11.4 

25 12.2 

22 11.2 

22 11.9 

21 11.1 

20 11.0 

20 12.0 

19 11.2 

20 10.8 

20 11.9 

36 10.6 

25 10.7 

22 11.2 

252 

247 

251 

251 

252 

253 

247 

241 

240 

230 

222 

218 

218 

21 5 

210 

214 

214 

208 

204 

202 

198 

195 

188 

170 

143 

114 

240 

207 

154 

47 

44 

45 

48 

43 

44 

48 

47 

51 

50 

46 

48 

50 

50 

51 

50 

51 

50 

53 

54 

51 

55 

58 

68 

73 

85 

47 

52 

71 

a Grams of feed consumed per animal per day. 

Milligrams of methylphenidate hydrochloride consumed per kilogram body weight per day. 
282 Methylphenidate Hydrochloride, NTP TR 439 

of Methylphenidate Hydrochloride 

Feed and Compound Consumption by Male Mice in the 2-Year Feed Study 

TABLE J3 

104 

101 

97 

93 

89 

85 

81 

77 

73 

69 

66 

61 

57 

53 

48 

45 

41 

37 

33 

29 

25 

21 

17 

13 

9 

5 

2 

4.8 

4.7 

4.9 

4.6 

4.7 

5.2 

4.9 

5.0 

4.8 

4.7 

4.4 

4.5 

4.7 

4.2 

4.6 

4.8 

4.8 

4.3 

4.6 

4.4 

4.4 

4.2 

4.6 

4.8 

5.1 

5.0 

4.0 

53-104 4.7 

14-52 4.5 

1-13 4.7 

Mean for weeks 

45.6 

44.8 

44.6 

45.9 

45.8 

46.1 

46.2 

44.9 

44.3 

43.7 

44.4 

43.0 

43.9 

43.6 

45.3 

45.1 

44.1 

44.1 

42.6 

41.1 

39.4 

37.9 

35.1 

32.6 

29.4 

26.7 

23.4 

44.8 

41.6 

28.0 

4.8 

4.8 

4.9 

4.5 

4.8 

4.7 

5.2 

5.0 

4.6 

4.7 

4.8 

4.8 

4.7 

4.2 

4.5 

4.5 

4.8 

4.6 

4.5 

4.4 

4.6 

4.3 

5.0 

4.9 

5.5 

5.1 

4.0 

4.8 

4.6 

4.9 

44.4 

44.8 

45.7 

47.3 

46.1 

46.4 

46.5 

44.7 

44.7 

44.6 

45.5 

44.1 

44.2 

44.9 

45.0 

45.3 

44.4 

44.1 

42.8 

41.5 

40.0 

38.0 

35.1 

31.6 

28.5 

26.8 

23.0 

45.3 

41.8 

27.5 

9 4.0 

10 5.3 

10 5.8 

8 4.9 

7 5.1 

6 4.3 

6 4.4 

5 4.4 

5 4.6 

5 4.4 

5 4.5 

5 4.5 

5 4.4 

5 4.2 

5 4.5 

5 4.7 

5 4.6 

5 4.7 

5 4.6 

6 5.0 

6 5.1 

5 5.1 

5 4.9 

5 4.4 

5 4.8 

5 4.7 

5 4.7 

9 5.0 

6 ,4.5 

5 4.7 

40.5 

40.8 

41.1 

42.6 

43.0 

42.4 

42.4 

40.7 

41.7 

41.4 

42.0 

40.8 

41.5 

42.1 

42.8 

42.8 

42.1 

41.6 

40.4 

39.4 

38.1 

35.7 

33.2 

30.6 

28.2 

25.7 

22.8 

41.6 

39.6 

26.8 

43 3.9 

51 5.5 

52 5.7 

40 5.6 

38 5.1 

30 4.5 

29 4.6 

28 4.3 

28 4.7 

27 4.6 

27 4.8 

26 4.6 

26 4.4 

25 4.3 

27 4.7 

29 4.9 

27 4.8 

28 4.9 

28 4.9 

31 5.0 

30 5.3 

30 5.3 

28 4.7 

26 4.3 

29 5.0 

29 4.7 

29 4.8 

47 5.2 

29 4.6 

28 4.8 

42.3 

43.1 

43.9 

44.5 

44.3 

44.1 

44.7 

42.6 

42.8 

42.4 

43.1 

41:3 

41.5 

42.0 

42.7 

43.5 

42.7 

42.0 

39.9 

39.4 

37.5 

35.8 

33.5 

30.5 

28.1 

26.0 

22.2 

43.0 

39.7 

26.7 

56 

54 

57 

48 

53 

60 

60 

58 

57 

57 

56 

59 

56 

51 

52 

53 

56 

54 

58 

55 

61 

63 

76 

91 

101 

105 

89 

56 

59 

97 

a Grams of feed consumed per animal per day. 

Milligrams of methylphenidate hydrochloride consumed per kilogram body weight per day. 
Feed and Compound Consumption 283 

of Methylphenidate Hydrochloride 

Feed and Compound Consumption by Female Mice in the 2-Year Feed Study 

TABLE 54 

(s/da~)~ Weight (%day) Weight Dayb &/day) Weight Day 

Feed Body Feed Body Dosd Feed Body Do& Feed Body Do4 

0 ppm 50 vpm 250 vpm 500 vvm 

(%day) weight Day 

Week (9) (g) (mtdk"ay) (€9 (WwdaY) (9) (mglkglday) 

105 

102 

98 

94 

90 

86 

82 

78 

73 

69 

66 

62 

58 

54 

50 

46 

42 

38 

34 

30 

25 

21 

17 

14 

10 

5 

2 

5.6 

5.1 

5.7 

5.8 

5.6 

5.8 

6.8 

5.8 

6.2 

6.1 

5.1 

5.5 

5.2 

5.1 

5.4 

5.1 

5.2 

5.5 

5.5 

5.5 

5.7 

4.9 

5.5 

5.9 

5.9 

5.6 

4.7 

53-105 5.7 

14-52 5.4 

1-13 5.4 

Mean for weeks 

43.7 

43.5 

43.4 

44.6 

43.5 

44.4 

45.1 

43.1 

42.7 

42.6 

40.8 

41.3 

40.2 

40.1 

41.6 

41.2 

40.1 

39.4 

38.5 

36.0 

34.3 

32.8 

30.4 

27.4 

25.0 

21.4 

18.9 

42.8 

36.2 

21.8 

5.9 

5.5 

5.8 

5.9 

5.5 

5.5 

5.9 

5.7 

6.3 

5.5 

5.2 

5.4 

5.5 

5.3 

5.4 

5.1 

5.5 

5.6 

5.3 

5.4 

5.6 

5.1 

5.9 

5.9 

5.6 

5 .o 

4.2 

5.6 

5.5 

4.9 

42.8 

43.6 

43.8 

44.7 

44.1 

44.0 

43.6 

42.6 

42.5 

41.3 

40.5 

39.8 

39.5 

40.2 

40.9 

40.8 

39.4 

38.5 

37.7 

34.9 

33.5 

32.1 

30.3 

27.6 

25.0 

21.8 

19.0 

42.4 

35.6 

21.9 

11 4.2 

11 5.6 

11 5.9 

11 5.9 

10 6.2 

8 5.0 

8 5.8 

8 5.4 

7 5.8 

7 5.5 

7 5.7 

6 5.4 

7 5.1 

7 4.8 

7 5.5 

7 5.3 

6 5.5 

7 6.0 

7 6.3 

7 5.7 

7 5.9 

6 6.0 

6 5.8 

7 5.8 

7 5.8 

6 5.4 

7 6.2 

11 5.2 

8 5.6 

7 5.7 

40.7 

41.0 

42.4 

43.9 

44.1 

44.1 

43.2 

42.4 

42.1 

41.9 

40.4 

39.7 

38.8 

40.0 

40.3 

40.6 

38.9 

38.1 

37.1 

34.7 

33.8 

31.1 

28.9 

25.9 

24.1 

21.7 

18.7 

41.8 

34.9 

21.5 

56 4.4 

65 5.8 

61 5.7, 

57 5.8 

54 , 6.5 

41.. . . . 4.9 

43 5.8 

39 5.1 

39 5.7 

36 5.4 

37 5.5 

33 5.3 

32 5.1 

30 5.2 

36 5.7 

33 5.2 

34 5.3 

36 6.0 

38 6.3 

34 5.8 

34 5.7 

34 5.9 

33 5.7 

33 5.9 

34 6.2 

33 5.5 

38 6.1 

61 5.3 

41 5.5 

34 5.7 

42.4 

43.3 

44.7 

44.3 

44.8 

45.1 

45.7 

44.0 

43.6 

43.1 

41.4 

41.1 

40.1 

41.6 

41.3 

41.9 

40.7 

39.4 

38.6 

36.4 

35.3 

33.0 

29.8 

26.8 

24.7 

21.8 

18.9 

43.2 

36.3 

21.8 

72 

63 

69 

67 

63 

65 

62 

66 

72 

69 

64 

64 

71 

63 

62 

64 

68 

68 

73 

71 

82 

75 

109 

108 

116 

133 

117 

67 

78 

122 

a Grams of feed consumed per animal per day. 

Milligrams of methylphenidate hydrochloride consumed per kilogram body weight per day. 
Methylphenidate Hydrochloride, NTP TR 439 
285 

AND CONTAMINANT LEVELS 

INGREDIENTS, NUTRIENT COMPOSITION, 

APPENDIX K 

IN NIH-07 RAT AND MOUSE RATION 

TABLE K1 Ingredients of NIH-07 Rat and Mouse Ration 

TABLE K2 Vitamins and Minerals in NIH-07 Rat and Mouse Ration 

TABLE K3 Nutrient Composition of NIH-07 Rat and Mouse Ration 

TABLE K4 Contaminant Levels in NIH-07 Rat and Mouse Ration 

............................... 

288 

287 

286 

286 

...................... 

....................... 

........................ 
286 Methylphenidate Hydrochloride, NTP TR 439 

Ingredients of NIH-07 Rat and Mouse Ration" 

TABLE K1 

Ingredientsb Percent by Weight 

Premixes (vitamin and mineral) 

Salt 

Ground limestone 

Dicalcium phosphate 

Dry molasses 

Dried brewer's yeast 

Soy oil 

Corn gluten meal (60% protein) 

Alfalfa meal (dehydrated, 17% protein) 

Dried skim milk 

Wheat middlings 

Fish meal (60% protein) 

Soybean meal (49% protein) 

Ground hard winter wheat 

Ground #2 yellow shelled corn 

10.00 

10.00 

12.00 

23.00 

24.50 

0.25 

0.50 

0.50 

1.25 

1.50 

2.00 

2.50 

3.00 

4.00 

5.00 

a NCI, 1976; NIH, 1978 

Ingredients were ground to pass through a U.S. Standard Screen No. 16 before being mixed. 

Vitamins and Minerals in NIH-07 Rat and Mouse Ration" 

TABLE K2 

Amount Source 

Vitamins 

A 

K3 

D3 

Thiamine 

Riboflavin 

d-Pantothenic acid 

Niacin 

Folic acid 

Choline 

d-a-Tocopheryl acetate 

Biotin 

Pyridoxine 

BlZ 

Zinc 

Manganese 

Iron 

Minerals 

Cobalt 

Iodine 

Copper 

10.0 g 

3:4 g 

18.0 g 

30.0 g 

2.2 g 

560.0 g 

20,Ooo IU 

2.8 g 

4,600,000 IU 

5,500,OOO IU 

4,000 fig 

140.0 mg 

1.7 g 

120.0 g 

0.4 g 

1.4 g 

4.0 g 

16.0 g 

60.0 g 

Menadione 

D-activated animal sterol 

Stabilized vitamin A palmitate or acetate 

Choline chloride 

Thiamine mononitrate 

d-Calcium pantothenate 

d-Biotin 

F'yridoxine hydrochloride 

Cobalt carbonate 

Calcium iodate 

Copper sulfate 

Zinc oxide 

Manganous oxide 

Iron sulfate 

" Per ton (2,OOO Ib) of finished product 
Feed Analysis 287 

Nutrient Composition of NIH-07 Rat and Mouse Ration 

TABLE K3 

Deviation 

Mean f Standard 

Nutrient Rw4e Number of Samples 

Ash (% by weight) 

Crude fiber (% by weight) 

Crude fat (% by weight) 

Protein (% by weight) 

Amino Acids (% of total die!) 

Valine 

mine 

Tryptophan 

Threonine 

Phenylalanine 

Methionine 

Lysine 

Leucine 

Isoleucine 

Histidine 

Glycine 

Cystine 

Arginine 

Essential Fatty Acids (% of total diet) 

Linolenic 

Linoleic 

Vitamins 

Choline (ppm) 

Vitamin B,, (ppb) 

Biotin (ppm) 

Folic acid (ppm) 

Pyridoxine (ppm) 

Pantothenic Acid (ppm) 

Niacin (ppm) 

Riboflavin (ppm) 

Thiamine (ppm) 

a-Tocopherol (ppm) 

Vitamin D (IUkg) 

Vitamin A (IUkg) 

Minerals 

Sulfur (%) 

Magnesium (%) 

Sodium (%) 

Chloride (W) 

Potassium (%) 

Phosphorus (%) 

Calcium (I) 

Zinc (ppm) 

Manganese (ppm) 

Cobalt (ppm) 

Chromium (ppm) 

Iodine (ppm) 

Iron (PPW 

Copper (PPm) 

6.61 f 0.93 

3.54 f 0.32 

5.49 f 0.30 

22.66 f 0.78 

1.089, f 0.057 

0.677 f 0.105 

0.223 f 0.160 

0.896 f 0.055 

0.994 f 0.125 

0.437 f 0.115 

1.273 f 0.051 

1.972 * 0.052 

0.917 f 0.034 

0.580 f 0.024 

1.160 f 0.050 

0.306 f 0.075 

1.287 f 0.084 

0.277 0.036 

2.389 f 0.233 

19.76 f 2.65 

36.92 f 9.32 

4,450 f 1,382 

6,211 f 992 

3,068 2 314 

40.14 f 20.04 

0.267 f 0.049 

2.51 f 0.64 

9.25 f 2.62 

30.30 f 3.60 

100.95 f 25.92 

7.92 f 0.93 

0.274 f 0.063 

0.168 f 0.008 

0.315 f 0.344 

0.526 f 0.092 

0.887 f 0.067 

0.96 f 0.06 

1.24 f 0.12 

11.50 f 2.40 

58.14 f 9.91 

92.24 f 5.35 

0356.2 f 90.0 

0.797 f 0.23 

1.71 f 0.45 

3.70 f 1.14 

2.41 - 7.27 

3.00 - 4.40 

4.80 - 5.90 

21.30 - 24.10 

0.962 - 1.170 

0.564 - 0.794 

0.107 - 0.671 

0.824 - 0.985 

0.665 - 1.110 

0.306 - 0.699 

1.200 - 1.370 

1.850 - 2.040 

0.867 - 0.965 

0.531 - 0.608 

1.060 - 1.220 

0.181 - 0.400 

1.100 - 1.390 

0.210 - 0.320 

1.830 - 2.570 

2,400 - 3,430 

10.6 - 65.0 

0.19 - 0.35 

1.80 - 3.70 

5.60 - 14.0 

23.0 - 34.6 

65.0 - 150.0 

6.10 - 9.00 

15.0 - 28.0 

22.5 - 48.9 

3,OOO - 6,300 

4,500 - 8,240 

8.090 - 15.39 

46.10 - 81.60 

81.70 - 99.40 

255.0 - 523.0 

0.208 - 0.420 

0.151 - 0.180 

0.258 - 0.370 

0.380 - 0.635 

0.772 - 0.971 

0.85 - 1.10 

0.96 - 1.45 

0.490 - 1.150 

0.85 - 2.09 

1.52 - 5.83 

25 

25 

25 

25 

10 

10 

10 

10 

10 

10 

10 

10 

10 

10 

10 

10 

10 

9 

9 

9 

10 

10 

10 

10 

10 

9 

10 

25 

9 

4 

25 

10 

10 

10 

10 

10 

10 

10 

10 

8 

8 

25 

25 

6 

9 
288 Methylphenidate Hydrochloride, NTP TR 439 

Contaminant Levels in NIH-07 Rat and Mouse Ration 

TABLE K4 

Deviationa 

Mean f Standard 

Range Number of Samples 

Cadmium (ppm) 

Arsenic (ppm) 

Contaminants 

(PPm) 

Nitrite nitrogen (ppm) 

Nitrate nitrogen (ppm 

Aflatoxins (ppb) 

Selenium (ppm) 

Mercuty (PP@ 

b" 

BHT (PPm)" 

BHA (PPWC 

N-Nitrosopyrrolidine (ppb) 

N-Nitrosodimethylamine (p b)f 

Total Nitrosoamines (ppb)f 

E. coli (MPN/g) 

Coliform (MPN/g)e 

Aerobic plate aunt (CFV/g)d 

P 

Pesticides (ppm) 

a-BHCg 

&BHC 

1-BHC 

&BHC 

Endosulfan sulfate 

Endosulfan I1 

Endosulfan I 

Malathion 

Ethyl parathion 

Methyl parathion 

Diazinon 

Trithion 

Ethion 

Ronnel 

Estimated PCBs 

Toxaphene 

Chlordane 

Telodrin 

Endrin 

Dieldrin 

Methoxychlor 

Mirex 

HCB 

DDT 

DDD 

DDE 

Heptachlor epoxide 

Aldrin 

Heptachlor 

0.35 & 0.29 

1.00 k 0.27 

2.20 f 1.07 

0.24 f 0.26 

22.28 k 8.54 

<5.0 

0.37 & 0.10 

0.05 & 0.01 

0.25 & 0.16 

1.80 f 1.45 

7.78 k 3.07 

9.59 & 3.67 

4.76 k 7.97 

181.0 * 233.0 

294,360 f 313,925 

CO.10 

co.02 

<0.02 

<0.1 

<0.05 

<0.02 

CO.01 

<0.2 

<0.1 

<0.05 

co.01 

<0.01 

CO.01 

<0.05 

<0.01 

<0.01 

<0.01 

<0.01 

<0.01 

<0.01 

co.01 

<0.01 

co.01 

co.01 

<0.02 

<0.01 

<0.03 

<0.01 

co.01 

0.17 f 0.20 

0.05 - 0.98 

0.20 - 0.60 

0.05 - 0.08 

0.05 - 0.60 

<3.00 - 43.00 

C3.00 - 1,100 

37,000 - l,u#),OOO 

<1.00 - 2.00 

eO.10 - 6.00 

<0.10 - 1.00 

10.00 - 37.00 

1.00 - 5.40 

2.90 - 14.00 

3.90 - 19.40 

0.05 - 0.85 

25 

25 

25 

25 

25 

25 

25 

25 

25 

25 

25 

25 

25 

25 

25 

25 

25 

25 

25 

25 

25 

25 

25 

25 

25 

25 

25 

25 

25 

25 

25 

25 

25 

25 

25 

25 

25 

25 

25 

25 

25 

25 

25 

25 

25 
Feed Analysis 289 

Contaminant Levels in NIH-07 Rat and Mouse Ration (continued) 

TABLE K4 

BHC is hexachlorocyclohexane or benzene hexachloride. 

All values were corrected for percent recovery. 

MPN = most probable number 

CW = colony forming units 

Sources of contamination: sou oil and fish meal 

Sources of contamination: alfalfa, grains, and fish meal 

For values less than the limit of detection, the detection limit is given as the mean. 
290 Methylphenidate Hydrochloride, NTP TR 439 
291 

SENTINEL ANIMAL PROGRAM 

APPENDIX L 

in the 13-Week and 2-Year Feed Studies of Methylphenidate Hydrochloride . . . . l . . . . . 294 

TABLE L1 Murine Virus Antibody Determinations for Rats and Mice 

METHODS.. ................... ................................................ 292 
292 Methylphenidate Hydrochloride, NTP TR 439 

SENTINEL ANIMAL PROGRAM 

source and weanling groups as the animals used for the studies of chemical compounds. 

are subject to identical environmental conditions. The sentinel animals come from the same production 

serology on sera from extra (sentinel) animals in the study rooms. These animals and the study animals 

evaluation of chemical compounds. Under this program, the disease state of the rodents is monitored via 

Animal Program is part of the periodic monitoring of animal health that occurs during the toxicologic 

optimally clean facilities to eliminate potential pathogens that may affect study results. The Sentinel 

Rodents used in the Carcinogenesis Program of the National Toxicology Program are produced in 

METHODS 

(Bethesda, MD) for viral titer screening. The following tests were performed: 

rats. The samples were processed appropriately and were submitted to Microbiological Associates, Inc. 

At the end of the 13-week study, serum was collected from the orbital sinuses of control male and female 

Rats 

ELISA 

Method of Analvsis 

Study termination 

Study termination 

Time of Analvsis 

RCV/SDA 

Mycoplasma 

(Rat coronavirus/sialodacryoadenitis virus) 

Sendai 

PVM (Pneumonia virus of mice) 

KRV (Kilham rat virus) 

H-1 (Toolan’s H-1 virus) 

Hemagglutination Inhibition 

Study termination 

Study termination 

Study termination 

Study termination 

Inc., and screened for the following: 

titers. Blood from each collection was appropriately processed, shipped to Microbiological Associates, 

positive viral titers for RCV/SDA, additional animals were bled at various time points to monitor the sera 

from five male and five female animals at terminal sacrifice. Because some sentinel animals showed 

five female rats at the beginning of the study, at approximately 6-month intervals during the study, and 

For the 2-year study, serum was collected from the retroorbital sinus of four to five male and four to 

ELISA 

Method of Analvsis 

Sendai 

RCV/SDA 

PVM 

Mycoplasma pulmonis 

Mycoplasma arthritidis 

Hemagglutination Inhibition 

KRV 

H- 1 

Immunofluorescence Assay 

RCV/SDA 

Time of Analvsis 

Study initiation, 6, 7, 16, 18, and 24 months 

Study initiation, 6, 7, 16, 18, and 24 months 

6, 7, 16, 18, and 24 months 

24 months 

24 months 

6, 7, 16, 18, and 24 months 

6, 7, 16, 18, and 24 months 

16 and 24 months 
Sentinel Animal Program 293 

for viral titer screening. The following tests were performed: 

mice. The samples were processed appropriately and were submitted to Microbiological Associates, Inc. 

At the end of the 13-week studies, serum was collected from the orbital sinuses of control male and female 

Mice 

Complement Fixation 

Method of Analvsis 

RCVISDA 

Mycoplasma 

Mouse adenoma virus 

LCM (lymphocytic choriomeningitis virus) 

Sendai 

Reovirus 3 

Polyoma virus 

PVM 

MVM (minute virus of mice) 

GDVII (mouse encephalomyelitis virus) 

Ectromelia virus 

ELISA 

Hemagglutination Inhibition 

Time of Analvsis 

Study termination 

Study termination 

Study termination 

Study termination 

Study termination 

Study termination 

Study termination 

Study termination 

Study termination 

Study termination 

Study termination 

shipped to Microbiological Associates, Inc., and screened for the following: 

and five female animals at terminal sacrifice. Blood from each collection was appropriately processed, 

five female mice at the beginning of the study, at 6, 12, and 20 months into the study, and from five male 

For the 2-year study, serum was collected from the retroorbital sinus of two to five male and two to 

ELISA 

Method of Analvsis 

Sendai 

Reovirus 3 

PVM 

M. pulmonis 

M. arthritidis 

MHV (Mouse hepatitis virus) 

Mouse adenoma virus 

MVM 

LCM 

GDVII 

Ectromelia virus 

CARB (Cilia-associated respiratory bacillus) 

MVM 

Polyoma virus 

K (Papovavirus) 

Reovirus 3 

LCM 

EDIM (Epizootic diarrhea of infant mice) 

Hemagglutination Inhibition 

Immunofluorescence Assay 

Time of Analvsis 

6, 12, 18, and 24 months 

6 and 12 months 

6,12,18, and 24 months 

24 months 

24 months 

6,12,18, and 24 months 

6, 12, 18, and 24 months 

12, 18, and 24 months 

12 and 18 months 

6,12,18, and 24 months 

6, 12, 18, and 24 months 

12 months 

6 months 

6, 12,18, and 24 months 

6, 12, 18, and 24 months 

20 and 24 months 

6 and 24 months 

6, 12, 18, and 24 months 

Results of serology testing for sentinel animals are presented in Table L1. 
294 Methylphenidate Hydrochloride, NTP TR 439 

of Methylphenidate Hydrochloride 

Murine Virus Antibody Determinations for Rats and Mice in the 13-Week and 2-Year Feed Studies 

TABLE L1 

Interval 

in Sentinel Animals 

Incidence of Antibody 

Reaction For 

Positive Serologic 

13-Week Studies 

Rats 

Study termination 

Mice 

Study termination 

2-Year Studies 

Rats 

16 months 

7 months 

6 months 

Study initiation 

24 months 

18 months 

Mice 

24 months 

18 months 

12 months 

6 months 

on0 

on0 

None positive 

None positive 

None positive 

None positive 

None positive 

None positive 

a Positive using ELISA 

Positive using immunofluorescence assay 
PRINTED AS OF JUNE 1995 

NATIONAL TOXICOLOGY PROGRAM TECHNICAL REPORTS 

TR No. CHEMICAL 

247 L-Ascorbic Acid 

246 Chrysotile Asbestos (Hamsters) 

245 Melamine 

244 Polybrominated Biphenyl Mixture 

243 Trichlorethylene (Rats and Mice) 

242 Diallyl Phthalate (Mice) 

240 Propyl Gallate 

239 Bis(2-chloro-1-methylethy1)ether 

238 Ziram 

237 1,1,1,2-Tetrachloroethane 

236 D-Mannitol 

235 Zearalenone 

234 Allyl Isothiocyanate 

233 2-Biphenylamine Hydrochloride 

232 Pentachloroethane 

23 1 Stannous Chloride 

230 Agar 

229 Guar Gum 

228 Vinylidene Chloride 

227 Gum Arabic 

226 C.I. Solvent Yellow 14 

225 D & C Red No. 9 

224 Tara Gum 

223 Eugenol 

222 C.I. Disperse Yellow 3 

221 Locust Bean Gum 

220 C.I. Acid Red 14 

219 2,6-Dichloro-p-phenylenediamine 

217 Di(2-ethy1hexyl)phthalate 

216 11-Aminoundecanoic Acid 

215 Bisphenol A 

214 Caprolactam 

213 Butyl Benzyl Phthalate 

212 Di(2-ethylhexy1)adipate 

211 C.I. Acid Orange 10 

210 1,2-Dibrornoethane 

209 2,3,7,8-Tetrachlorodibenzo-p-dioxin (Gavage) 

208 FD & C Yellow No. 6 

207 Cytembena 

206 1,2-Dibromo-3-chloropropane 

201 2,3,7,8-Tetrachlorodibenzo-pdioxin (Dermal) 

,249 Amosite Asbestos (Hamsters). 

,251 2.4: & 2.6-Toluene Diisocyanate 1 

252 Geranyl Acetate 

253 Allyl Isovalerate 

254 Dichloromethane (Methylene Chloride) 

255 1,2-Dichlorobenzene 

257 Diglycidyl Resorcinol Ether 

259 Ethyl Acrylate 

261 Chlorobenzene 

263 1.2-Dichloropropane 

266 Monuron 

267 1.2-Propylene Oxide 

269 Telone 11" (1,3-Dichloropropene) 

271 HC Blue No. 1 

272 Propylene 

,, 250 Benzyl Acetate 

' ,248 4,4'-Methylenedianiline Dihydrochloride. 

.. 

~VE~NT PRINTING OFFICE:1995-398-284/40070 

TR No. CHEMICAL 

273 Trichloroethylene (Four Rat Strains) 

274 Tris(2-ethylhexy1)phosphate 

275 2-Chloroethanol 

276 8-Hydroxyquinoline 

277 Tremolite 

278 2,6-Xylidine 

279 Amosite Asbestos 

280 Crocidolite Asbestos 

281 HC Red No. 3 

282 Chlorodibromomethane 

284 Diallylphthalate (Rats) 

285 C.I. Basic Red 9 Monohydrochloride 

287 Dimethyl Hydrogen Phosphite 

288 1.3-Butadiene 

289 Benzene 

291 Isophorone 

293 HC Blue No. 2 

294 Chlorinated Trisodium Phosphate 

295 Chrysotile Asbestos (Rats) 

296 Tetrakis(hydroxymethy1)phosphonium Sulfate & 

335 C.I. Acid Orange 3 

334 2-Amino-5-nitrophenoI 

333 N-Phenyl-2-naphthylamine 

332 2-Mercaptobenzothiazole 

331 Malonaldehyde, Sodium Salt 

330 4-Hexylresorcinol 

329 1,2-Epoxybutane 

328 Methyl Carbamate 

327 Xylenes (Mixed) 

326 Ethylene Oxide 

325 Pentachloronitrobenzene 

324 Boric Acid 

323 Dimethyl Methylphosphonate 

322 Phenylephrine Hydrochloride 

321 Bromodichloromethane 

320 Rotenone 

3 19 1,4-Dichlorobenzene 

3 18 Ampicillin Trihydrate 

3 17 Chlorpheniramine Maleate 

316 1-Chloro-2-methylpropene 

315 Oxytetracycline Hydrochloride 

314 Methyl Methacrylate 

313 Mirex 

312 nButy1 Chloride 

3 1 1 Tetrachloroethylene (Inhalation) 

310 Marine Diesel Fuel and JP-5 Navy Fuel 

309 Decabromodiphenyl Oxide 

308 Chlorinated Paraffins (C,,, 60% chlorine) 

307 Ephedrine Sulfate 

306 Dichloromethane (Methylene Chloride) 

305 Chlorinated Paraffins (Cz, 43% chlorine) 

304 Chlorendic Acid 

303 4-Vinylcyclohexene 

301 oPhenylpheno1 

300 3-Chloro-2-methylpropene 

299 C.I. Disperse Blue 1 

298 Dimethyl Morpholinophosphoramidate 

Tetrakis(hydroxymethy1)phosphoniurn Chloride 
PRINTED AS OF JUNE 1995 (CONT.) 

NATIONAL TOXICOLOGY PROGRAM TECHNICAL REPORTS 

TR No. CHEMICAL 

382 

381 

380 

379 

378 

377 

376 

375 

374 

373 

372 

37 1 

370 

369 

368 

367 

366 

365 

3 64 

363 

362 

361 

360 

359 

358 

357 

356 

355 

354 

353 

352 

35 1 

350 

349 

348 

347 

346 

345 

344 

343 

342 

341 

340 

339 

338 

337 

336 

389 

388 

387 

386 

385 

384 

Furfural 

d-Carvone 

Epinephrine Hydrochloride. 

2-Chloroacetophenone 

Benzaldehyde 

o-Chlorobenzalmalononitrik 

Allyl Glycidyl Ether 

Vinyl Toluene 

Glycidol 

Succinic Anhydride 

3,3-Dimethoxybenzidine Dihydrochloride 

Toluene 

Benzofuran 

a-Methylbenzyl Alcohol 

Nalidixic Acid 

Phenylbutazone 

Hydroquinone 

Pentaerythritol Tetranitrate 

Rhodamine 6G (C.I. Basic Red 1) 

Bromoethane (Ethyl Bromide) 

4-Vinyl-1-cyclohexene Diepoxide 

Hexachloroethane 

N,N-Dimethylaniline 

8-Methoxypsoralen 

Ochratoxin A 

Hydrochlorothiazide 

Furosemide 

Diphenhydramine Hydrochloride 

Dimethoxane 

2,4-Dichlorophenol 

N-Methylolacrylamide 

p-Chloroaniline Hydrochloride 

Tribromomethane 

Pentachlorophenol 

a-Methyldopa Sesquihydrate 

D-Limonene 

Chloroethane 

Roxarsone 

Tetracycline Hydrochloride 

Benzyl Alcohol 

Dichlorvos 

Nitrofurantoin 

Iodinated Glycerol 

2-Amino-4-nitrophenol 

Erythromycin Stearate 

Nitrofurazone 

Penicillin VK 

Sodium Azide 

Ethylene Thiourea 

Amphetamine Sulfate 

Tetranitromethane 

Methyl Bromide 

1,2,3-Trichloropropane 

TR No. CHEMICAL 

435 

434 

433 

432 

43 1 

430 

429 

428 

427 

426 

425 

424 

423 

422 

42 1 

420 

419 

418 

411 

416 

415 

414 

413 

412 

41 1 

410 

409 

408 

407 

406 

405 

404 

403 

402 

40 1 

400 

399 

398 

397 

396 

395 

394 

393 

392 

391 

390 

4,4’-Thiobis(6-t-butyl-m-cresol) 

1.3-Butadiene 

Tricresyl Phosphate 

Barium Chloride Dihydrate 

Benzyl Acetate 

C.I. Direct Blue 218 

Diethylphthalate 

Manganese (11) Sulfate Monohydrate 

Turmeric Oleoresin 

Corn Oil, Safflower Oil, and Tricaprylii 

Promethazine Hydrochloride 

o-Benzyl-p-chlorophenol 

Dihydrocoumarin 

coumarin 

Talc 

Triamterene 

HC Yellow 4 

p-Nitroaniline 

p-Nitrophenol 

o-Nitroanisole 

Polysorbate 80 

Pentachloroanisole 

Ethylene Glycol 

4,4-Diamino-2,2-stilbenedisulfonic Acid 

C.I. Pigment Red 23 

Naphthalene 

Quercetin 

Mercuric Chloride 

C.I. Pigment Red 3 

y-Butyrolactone 

C.I. Acid Red 114 

5.5-Diphenylhydantoin 

Resorcinol 

Furan 

2,4-Diaminophenol Dihydrochloride 

2,3-Dibromo-l-propanol 

Titanocene Dichloride 

Polybrominated Biphenyls 

C.I. Direct Blue 15 

Monochloroacetic Acid 

Probenecid 

Acetaminophen 

Sodium Fluoride 

Chlorinated Water and Chloraminated Water 

Tris(2-chloroethyl) Phosphate 

3,3’-Dimethylbemidme Dihydrochloride 

436 t-BUtyl Alcohol 

437 Hexachlorocyclopentadiene 

440 Ozone and OzonelNNK 

442 p-Nitrobenzoic Acid 

443 Oxazepam 

444 o-Benzyl-p-chlorophenol 

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