[Federal Register Volume 63, Number 148 (Monday, August 3, 1998)]
[Rules and Regulations]
[Pages 41190-41191]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-20534]


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DEPARTMENT OF HEALTH AND HUMAN SERVICES

Food and Drug Administration

 21 CFR Parts 522 and 556


Animal Drugs, Feeds, and Related Products; Florfenicol Solution

AGENCY: Food and Drug Administration, HHS.

ACTION: Final rule.

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SUMMARY: The Food and Drug Administration (FDA) is amending the animal 
drug regulations to reflect approval of a supplemental new animal drug 
application (NADA) filed by Schering-Plough Animal Health. The 
supplemental NADA provides for the subcutaneous use of florfenicol 
injectable solution in cattle for treatment of bovine respiratory 
disease, a new dosage, an additional slaughter withdrawal time, and an 
additional tolerance for residues in food.
EFFECTIVE DATE: August 3, 1998.
FOR FURTHER INFORMATION CONTACT: William T. Flynn, Center for 
Veterinary Medicine (HFV-133), Food and Drug Administration, 7500 
Standish Pl., Rockville, MD 20855, 301-594-1652.

SUPPLEMENTARY INFORMATION: Schering-Plough Animal Health Corp., 1095 
Morris Ave., Union, NJ 07083-1982, is sponsor of NADA 141-063 that 
provides for veterinary prescription use of Nuflor<Register> Injectable 
Solution (florfenicol) for intramuscular treatment of cattle for bovine 
respiratory disease at 20 milligrams per kilogram of body weight, with 
a second dose after 48 hours, and a 28-day slaughter withdrawal time. 
Schering-Plough filed a supplemental NADA providing for a single 
subcutaneous injection at 40 milligrams per kilogram of body weight, 
and a 38-day slaughter withdrawal time. The supplemental NADA is 
approved as of June 4, 1998, and the regulations are amended by 
revising 21 CFR 522.955(d)(1)(i) and (d)(1)(iii) to reflect the 
approval. The basis of approval is discussed in the freedom of 
information summary.
    In addition, the regulation concerning tolerances for residues of 
florfenicol in food (21 CFR 556.283) is amended to reflect an 
acceptable daily intake (ADI) of residues of the drug in food and a 
tolerance for residues in cattle muscle. The ADI is the amount of total 
drug residue that can be safely consumed daily for a lifetime. 
Previously, FDA had codified safe concentrations of animal drugs, the 
ADI corrected for consumption of various food products. Few individuals 
understood the relationship between safe concentrations, a value 
representing total drug residues, and tolerance, the part of the drug 
residue in a given tissue that is detected by an analytical method. To 
avoid confusion between the tolerance and safe concentration, FDA is 
codifying ADI's and removing safe concentrations.
    In accordance with the freedom of information provisions of 21 CFR 
part 20 and 514.11(e)(2)(ii), a summary of safety and effectiveness 
data and information submitted to support approval of this supplement 
may be seen in the Dockets Management Branch (HFA-305), Food and Drug 
Administration, 5630 Fishers Lane, rm. 1061, Rockville, MD 20852, 
between 9 a.m. and 4 p.m., Monday through Friday.
    Under section 512(c)(2)(F)(iii) of the Federal Food, Drug, and 
Cosmetic Act (21 U.S.C. 360b(c)(2)(F)(iii)), this supplemental approval 
for food-producing animals qualifies for 3 years of marketing 
exclusivity beginning June 4, 1998, because the supplemental 
application contains substantial evidence of the effectiveness of the 
drug involved, any studies of animal safety or, in the case of food-
producing animals, human food safety studies (other than bioequivalence 
or residue studies) required for approval and conducted or sponsored by 
the applicant. Three years marketing exclusivity is limited to 
subcutaneous use of the drug in cattle as approved in this supplement.
    FDA has determined under 21 CFR 25.33(a)(1) that this action is of 
a type that does not individually or cumulatively have a significant 
effect on the human environment. Therefore,

[[Page 41191]]

neither an environmental assessment nor an environmental impact 
statement is required.

List of Subjects

21 CFR Part 522
     Animal drugs.
21 CFR Part 556
    Animal drugs, Foods.
    Therefore, under the Federal Food, Drug, and Cosmetic Act and under 
authority delegated to the Commissioner of Food and Drugs and 
redelegated to the Center for Veterinary Medicine, 21 CFR parts 522 and 
556 are amended as follows:

PART 522--IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS

    1. The authority citation for 21 CFR part 522 continues to read as 
follows:

    Authority: 21 U.S.C. 360b.

    2. Section 522.955 is amended by revising paragraph (d)(1)(i) and 
the first four sentences of paragraph (d)(1)(iii) to read as follows:


 Sec. 522.955   Florfenicol solution.

* * * * *
    (d) * * *
    (1) * * *
    (i) Amount. For intramuscular injection use 20 milligrams per 
kilogram of body weight (3 milliliters per 100 pounds). A second dose 
should be given 48 hours later. Alternatively, a single subcutaneous 
injection of 40 milligrams per kilogram of body weight (6 milliliters 
per 100 pounds) may be used.
* * * * *
    (iii) Limitations. For intramuscular or subcutaneous use only. Do 
not inject more than 10 milliliters at each site. Injection should be 
given in the neck only. Do not slaughter within 28 days of last 
intramuscular treatment or within 38 days of subcutaneous treatment. * 
* *
* * * * *

PART 556--TOLERANCES FOR RESIDUES OF NEW ANIMAL DRUGS IN FOOD

    3. The authority citation for 21 CFR part 556 continues to read as 
follows:

    Authority: 21 U.S.C. 342, 360b, 371.

    4. Section 556.283 is revised to read as follows:

 Sec. 556.283   Florfenicol.

    (a) Acceptable daily intake (ADI). The ADI for total residues of 
florfenicol is 10 micrograms per kilogram of body weight per day.
    (b) Cattle. A tolerance of 3.7 parts per million (ppm) for 
florfenicol amine (marker residue) in liver (target tissue) is 
established. A tolerance of 0.3 ppm for florfenicol amine in cattle 
muscle is established.

    Dated: July 10, 1998.
Margaret Ann Miller,
Acting Director, Office of New Animal Drug Evaluation, Center for 
Veterinary Medicine.
[FR Doc. 98-20534 Filed 7-31-98; 8:45 am]
BILLING CODE 4160-01-F