**DATA EVALUATION RECORD**

**AMITRAZ/106201**

**NONGUIDELINE**

**STUDY TYPE: HUMAN TOLERANCE - DERMAL**

**MRID: 44639401**

Prepared for

Health Effects Division

Office of Pesticide Programs

U.S. Environmental Protection Agency

1801 Bell Street

Arlington, VA 22202

Prepared by

Toxicology and Hazard Assessment Group

Life Sciences Division

Oak Ridge National Laboratory

Oak Ridge, TN 37831

Task Order No. 61-2004

Primary Reviewer:

[Clint Skinner, Ph.D.. D.A.B.T.]{.underline} Signature:

Date:

Secondary Reviewers:

[H. Tim Borges, Ph.D., D.A.B.T.]{.underline} Signature:

Date:

[Robert H. Ross, M.S., Group Leader]{.underline} Signature:

Date:

Quality Assurance:

[Lee Ann Wilson, M.A.]{.underline} Signature:

Date:

Disclaimer

This review may have been altered subsequent to the contractor=s
signatures above.

Oak Ridge National Laboratory managed and operated by UT‑Battelle, LLC.,
for the U.S. Department of Energy under Contract No. DE‑AC05‑00OR22725.

**EPA Reviewer:** [Pamela M. Hurley, Ph.D.]{.underline} **Signature:**

**Reregistration Action Branch 3, Health Effects Division (7509C) Date**

**EPA Work Assignment Manager:** [Ghazi Dannan, Ph.D.]{.underline}
**Signature:**

**Registration Action Branch 3, Health Effects Division (7509C) Date**

[**TXR**\#]{.underline}: 0052737

**Supplemental**

  -----------------------------------------------------------------------
  **DATA EVALUATION RECORD**

  -----------------------------------------------------------------------

**Root TXR: 0013255**

**[STUDY TYPE]{.underline}**: Double Blind Tolerance Study in
Humans-Dermal.

> Non-Guideline.

**[PC CODE]{.underline}:** 106201 **[DP BARCODE]{.underline}:** N/A

**[SUBMISSION NO.]{.underline}:** N/A

**[TEST MATERIAL (PURITY)]{.underline}**: Amitraz technical (100% a.i.)

**[SYNONYMS]{.underline}:**
1,5-Di(2,4-dimethylphenyl)-3-methyl-1,3,5-triazapenta-1,4-diene; Baam;
Formamidine, NBmethyl-N\'-2,4-xylyl-N-(N-2,4-xylylformimidoyl)-;
Methyl-bis(2,4-xylyliminomethyl)amine; Mitac; Ovasyn; Taktic; Triazid

**[CITATION]{.underline}:** Langford, H. (1998). Amitraz (Code AE
B049974): Human volunteer double-blind tolerance study. Simbec Research
Ltd., Merthyr Tydfil, CF48 4DR United Kingdom. Study No. TOX 97228. July
28, l998. MRID 44639401. Unpublished.

**[SPONSOR]{.underline}:** AgrEvo USA Company, 2711 Centerville Road,
Wilmington, DE 19808.

**[EXECUTIVE SUMMARY]{.underline}:** In a double-blind sequential dosing
study with a randomized crossover and placebo group, eight healthy male
volunteers 32.0  6.8 years and 76.6  9.3 kg were given a total dose of
either 0, 8, 16 or 24 mg/kg Amitraz (Lot No. B570R, Batch No. 459732,
purity = 100%) applied dermally as four equal doses of 0, 2, 4 or 6
mg/kg in an aqueous 1:1 slurry every 2.5 hours over 10 hours according
to a random schedule. Starch, 1:1 in water, was used as a placebo. The
purpose of the study was to find a no effect level for acute
pharmacologi­cal effects following administration by repeated dermal
doses of Amitraz. The volunteers were evaluated for vital signs, ECG,
and psychomotor measurements (pupil critical flicker threshold and
reaction time in a choice scenario), hematology, clinical chemistry and
urinalysis before and after dosing. The parameters were selected on the
basis of the test material=s pharmacologi­cal activity (sedation,
hypotension and effects on body temperature in humans following oral
dosing).

Vital signs and ECG parameters were normal for all subjects. No
clinically significant changes were seen in pupil response. Psychomotor
performance results such as choice reaction time and critical flicker
fusion demonstrated no significant differences. None of the out-of-range
ECG events were considered clinically significant by the investigating
physician. Random out of normal range values for clinical chemistry were
without biological significance. No treatment-related effects were found
in hematological or urinalysis results.

This dermal toxicity study in humans is **Acceptable/Nonguideline** and
satisfies the intent of the study.

**[COMPLIANCE]{.underline}:** Signed and dated GCP, Quality Assurance,
and Data Confidentiality statements were provided.

**I. [MATERIALS AND METHODS]{.underline}**:

**A. [MATERIALS]{.underline}:**

  -------------------------- ------------------ ----------------------------------------------------
  **1. [Test                                    Amitraz
  material]{.underline}:**                      

                             **Description:**   off-white powder

                             **Lot/Batch #:**   Lot No. B570R, Batch No. 459732

                             **Purity:**        100%

                             **Compound         not reported
                             Stability:**       

                             **CAS No. of       33089-61-1
                             TGAI:**            

                             **Structure:**     ![](media/image1.png){width="1.5930555555555554in"
                                                height="1.4083333333333334in"}
  -------------------------- ------------------ ----------------------------------------------------

**2. [Vehicle and/or positive control]{.underline}:** water

  --------------------------- ----------------- --------------------------------------------------
  **3.                                          
  [Subjects]{.underline}:**                     

                              **Age:**          32.0  6.8 years

                              **Sex:**          male

                              **Weight:**       76.6  9.3 kg

                              **Height:**       1.75  0.05 m
  --------------------------- ----------------- --------------------------------------------------

**B. [STUDY DESIGN]{.underline}:**

**1. [In life dates:]{.underline}** Start: January 27, 1998; End:
February 17, 1998

**2. [Dose selection rationale]{.underline}:** Previous studies had
demonstrated no effect at 0.03 mg/kg and sedation at 0.25 mg/kg amitraz.
It was estimated that the maximum NOAEL was between 0.06 and 0.25 mg/kg
in humans. Before the start of the study, the study protocol was
reviewed and approved by an Ethics Committee. The study was done
according to the Helsinki (South Africa l996), ABPI Guidelines for
Medical Experiments in Non-Patient Volunteers, l998, amended l990 and
the ICH Harmonized Tripartite Guidelines for Good Clinical Practice.

3.  [Dosing:]{.underline} Each of the four study phases was 2 days
    duration with at least 7 days between phases (Table 1). For each
    phase of the study, one fourth of the total dose was administered at
    2.5 hour intervals to individual 20 cm^2^ sites on the forearm of
    the individual. A placebo of aqueous 1:1 corn starch was also used.
    The application sites were protected by semi-occlu­sive surgical
    gauze and left in place up to 10 hours. Each study individual was
    admitted to the Clinical Unit for 36 hours during test material
    application.

  ---------------- -------------- -------------- -------------- --------------
  **Table 1. Human                                              
  volunteer dosing                                              
  regimen**                                                     

  **Individual**   **Dermal dose                                
                   of amitraz                                   
                   (mg/kg)**                                    

                   **Phase I**    **Phase II**   **Phase III**  **Phase IV**

  1                P\*            8              16             24

  2                8              P              16             24

  3                8              16             P              24

  4                8              16             24             P

  5                P              8              24             24

  6                8              16             24             P

  7                8              P              16             24

  8                8              16             P              24

  \*P = Placebo                                                 
  (aqueous 1:1                                                  
  starch)                                                       
  ---------------- -------------- -------------- -------------- --------------

4.  [Examinations:]{.underline} Before the start of the study and after
    study completion, the following examinations were given.

+-----------------------------------+-----------------------------------+
| [Pre-study                        | [Post-study                       |
| examinations:]{.underline}        | examinations:]{.underline}        |
|                                   |                                   |
| > Medical history                 | > Physical exam                   |
| >                                 | >                                 |
| > Physical exam                   | > Weight                          |
| >                                 | >                                 |
| > Height                          | > Blood Pressure                  |
| >                                 | >                                 |
| > Weight                          | > Pulse                           |
| >                                 | >                                 |
| > Frame size                      | > Respiration rate                |
| >                                 | >                                 |
| > Body Mass Index                 | > 12-lead ECG                     |
| >                                 | >                                 |
| > Blood Pressure                  | > Laboratory safety screen        |
| >                                 | > (biochemistry, hematology,      |
| > Pulse                           | > urinalysis, drugs of abuse)     |
| >                                 | >                                 |
| > Respiration rate                | > Follow-up of unresolved adverse |
| >                                 | > events.                         |
| > 12-lead ECG                     |                                   |
| >                                 |                                   |
| > Laboratory safety screen        |                                   |
| > (biochemistry, hematology,      |                                   |
| > urinalysis, and drugs of abuse) |                                   |
| >                                 |                                   |
| > Compliance with                 |                                   |
| > inclusion/exclusion criteria    |                                   |
+-----------------------------------+-----------------------------------+

5.  [Observations:]{.underline} During each phase of the study, all
    adverse reactions, whether minor or serious and whether considered
    related to treatment or not, were recorded. The following were
    recorded during each treatment phase:

> Sitting blood pressure and pulse were recorded pre-dose at B1, B0.5,
> and 1, 3, 6, 12, 24, and 36 hours after treatment.
>
> ECGs were done pre-dose at B1 hour and 3, 6, 12, 24, and 36 hours
> following treatment.
>
> Psychomotor performance (times to critical eyelid flicker fusion and
> reaction time in a choice scenario at 0.5 hours before first dose and
> at 5 and 10 hours afterwards.

6.  [Hematology and clinical chemistry:]{.underline} Blood was collected
    pre-study, and at 36 hours after each phase of the study. The
    CHECKED (X) parameters were examined.

> **a. [Hematology:]{.underline}**

  ---- ------------------------------- ---- -------------------------------
  X    Hematocrit (HCT)                X    Leukocyte Differential Count

  X    Hemoglobin (HGB)                X    Mean corpuscular HGB (MCH)

  X    Leukocyte count (WBC)           X    Mean corpusc. HGB conc.(MCHC)

  X    Erythrocyte count (RBC)         X    Mean corpusc. volume (MCV)

  X    Platelet count                       
  ---- ------------------------------- ---- -------------------------------

> **b. Clinical chemistry:**

  ----------------- ------------------------------- ----------------- -------------------------------
  [X]{.underline}   [Potassium]{.underline}         [X]{.underline}   [Creatinine]{.underline}

  [X]{.underline}   [Sodium]{.underline}            [X]{.underline}   [Urea nitrogen]{.underline}

  [X]{.underline}   [Alanine aminotransferase (also [X]{.underline}   [Glucose]{.underline}
                    SGPT)]{.underline}                                

  [X]{.underline}   [Aspartate aminotransferase     [X]{.underline}   [Total bilirubin]{.underline}
                    (also SGOT)]{.underline}                          

  X                 Gamma glutamyl transferase      X                 Total protein (TP)
                    (GGT)                                             
  ----------------- ------------------------------- ----------------- -------------------------------

**7. [Urinalysis:]{.underline}** Urine was collected pre-dose and 0-24,
and 24-36 hours for the first phase. The CHECKED (X) parameters were
examined.

  ---- -------------------------------- --- -------------------------------
  X    Specific gravity/osmolality      X   Glucose

  X    pH                               X   Ketones

  X    Protein                          X   Bilirubin

                                        X   Blood/blood cells

                                        X   Urobilinogen
  ---- -------------------------------- --- -------------------------------

8.  [Statistics]{.underline}: Analysis of variance was used for vital
    signs and psychomotor measurements. Pairwise comparisons for each
    subject at each time-point were made by Dunnet=s test.

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III. [RESULTS]{.underline}

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63444. [Adverse Events and Clinical Signs]{.underline}: There were two
       adverse events reported by Subject 04. These were bruising on
       both upper arms after application of the placebo and unrelated to
       Amitraz treatment.

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1.  [Physiological Measurements]{.underline}: Vital signs and ECG
    parameters were normal for all subjects. No clinically significant
    changes were seen in pupil response. Psychomotor performance results
    such as choice reaction time and critical flicker fusion
    demonstrated no significant differences. None of the out of range
    ECG events were considered clinically significant by the
    investigating physician.

2.  [Hematology and Biochemistry:]{.underline} Random out of normal
    range values were found to be without clinical significance. No
    clinically significant effects related to treatment were found.

3.  [Urinalysis]{.underline}: Two abnormalities were detected which
    included bilirubin and blood traces. These were considered not
    clinically significant by the investigating physician.

4.  [Drugs of Abuse]{.underline}: No drugs of abuse were detected in any
    subject.

**III. [DISCUSSION]{.underline}** **[AND CONCLUSIONS:]{.underline}**

> **A. [INVESTIGATORS= CONCLUSIONS]{.underline}:**
>
> The investigators concluded that dermal doses of Amitraz (8mg/kg,
> 16mg/kg and 24mg/kg) were tolerated in 8 healthy male volunteers, with
> no adverse effects. A NOAEL of 24 mg/kg was suggested by the authors.
>
> **B. [REVIEWER COMMENTS]{.underline}**:
>
> This report has complete individual tables for all endpoints evaluated
> with statistics. No discrepancies in investigators= conclusions were
> found. The highest dose (24mg/kg) may be considered a NOAEL based on
> the parameters investigated. Reported clinical signs after human
> exposure to Amitraz in previous studies include drowsiness, loss of
> consciousness, confused mental state, or agitation which were observed
> following a single oral dose of 0.25 mg/kg (Ellenhorn, M.J. et al
> 1997). This study at 100 times that dose applied dermally indicates
> that dermal absorption is low. Depending on field dermal exposure and
> study results, a dermal absorption study with human skin may be
> advised.

C.  [STUDY DEFICIENCIES]{.underline}:

> There are no EPA standards for human dermal studies. In this study of
> Amitraz, most of the known human effects were covered by the
> investigations and the doses were carefully chosen. More discussion of
> known human effects, rationale for choosing parameters for evaluation
> and any known additivity of doses and serious effects at higher doses
> or longer exposure would be helpful.

**Protocol Deviations:** Subject 5 received 24 mg/kg Amitraz in error
during Periods 3 and 4.

**References:**

Ellenhorn, M. S. Schonwald, G. Ordog, J. Wasserberger. Ellenhorn\'s
Medical Toxicology: Diagnosis and Treatment of Human Poisoning. 2nd ed.
Baltimore, MD: Williams and Wilkins, 1997. pg. 1730 as Cited in HSDB
2004.