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Administrative data

Endpoint:
acute toxicity: oral
Type of information:
experimental study
Adequacy of study:
key study
Study period:
28 August 2003 to 16 September 2003
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2004
Report date:
2004

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
OECD Guideline 420 (Acute Oral Toxicity - Fixed Dose Method)
Deviations:
no
Qualifier:
according to guideline
Guideline:
EU Method B.1 bis (Acute Oral Toxicity - Fixed Dose Procedure)
Deviations:
no
GLP compliance:
yes
Test type:
fixed dose procedure
Limit test:
yes

Test material

Constituent 1
Chemical structure
Reference substance name:
-
EC Number:
412-600-3
EC Name:
-
Cas Number:
152827-98-0
Molecular formula:
C32H48ClN5O3
IUPAC Name:
Tetradecyl 4'-(6-tert-butyl-7-chloro-3H-pyrazolo[1,5- b][1,2,4]triazol-2-yl)succinanilate
Test material form:
solid: particulate/powder
Details on test material:
- Name of test material (as cited in study report): Butanoic acid, 4-[[4-[7-chloro-6-(1,1-dimethylethyl)-1H-pyrazolo[1,5-b][1,2,4]triazol-2-yl]phenyl]amino]-4-oxo-, tetradecyl ester
- HAEL Number: 2003-0090
- KAN: 632021-1
- CIN: 10084241
- SRID or Lot No.: DEV84241
- Physical state and appearance: brown powder
- Storage conditions of test material: at room temperature
- Purity determination: 96.5 weight percent
- Stability: stable

Test animals

Species:
rat
Strain:
Sprague-Dawley
Sex:
female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Age at study initiation: 9 to 10 weeks of age
- Weight at study initiation: 194.43 to 225.30 grams
- Fasting period before study: Fasted overnight
- Housing: Animals were housed in an Association for Assessment and Accreditation of Laboratory Animal Care International-accredited vivarium in accordance with the Guide for the Care and Use of Laboratory Animals (National Research Council, 1996). The rats were singly housed in suspended, stainless-steel, wire mesh cages. Cages and racks were washed once a week. Absorbent paper, used to collect excreta, was changed at least three times a week.
- Diet: Certified Rodent Diet (pelleted) was available ad libitum.
- Water: Water was available ad libitum through an automatic watering system. The source of the water was the local public water system.
- Acclimation period: The animals were isolated upon arrival and allowed to acclimate for a period of 5 days. Animals were judged to be healthy prior to testing.

ENVIRONMENTAL CONDITIONS
- Temperature: 20.8 - 24.6 °C
- Humidity: 43.4 - 71.0 %
- Photoperiod: A photoperiod of 12 hours of light was maintained.

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
CMC (carboxymethyl cellulose)
Remarks:
0.5 % aqueous suspension
Details on oral exposure:
VEHICLE
- Concentration in vehicle: For the 300 and 2000 mg/kg dose levels, the test substance was administered as a 3 or 20 % suspension in the vehicle, respectively.
- Amount of vehicle (if gavage): The vehicle was a 0.5 % aqueous suspension of carboxymethylcellulose.

TEST SUBSTANCE EXPOSURE
- A single dose of the test substance was administered by gavage to animals that had been fasted overnight.

Doses:
300 and 2000 mg/kg dose levels
No. of animals per sex per dose:
In a preliminary sighting study, an initial dose of 300 mg/kg of the test substance was administered to a single female rat. Since no signs of toxicity were noted for this rat, a higher dose of 2000 mg/kg was administered to a second female rat. Based on the results of the sighting study, 2000 mg/kg was administered to an additional four female rats.
Control animals:
not specified
Details on study design:
- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Body weights were collected on Days 0 (prior to treatment), 7, and 14. Animals were observed three times on the day of dosing (Day 0), and once each day thereafter for the duration of the experiment. Observations included, but were not limited to, examination of the hair, skin, eyes, mucous membranes, motor activity, feces, urine, respiratory system, circulatory system, autonomic nervous system, central nervous system, and behavior patterns.
- Necropsy of survivors performed: yes
Statistics:
No statistical procedures were required during the study. No dose/mortality curve was constructed since graphs become statistically useful only with the use of large numbers of animals and dose groups.

Results and discussion

Preliminary study:
An initial dose of 300 mg/kg of the test substance was administered to a single female rat. Since no signs of toxicity were noted for this female, a higher dose of 2000 mg/kg was administered to a second female rat. No mortality or abnormal clinical signs were noted during the sighting study. Therefore, 2000 mg of the test substance/kg body weight was administered to an additional four female rats.
Effect levels
Key result
Sex:
female
Dose descriptor:
LD50
Effect level:
> 2 000 mg/kg bw
Based on:
test mat.
Mortality:
No mortality was observed during the 14-day observation period for rats administered a dose of 2000 mg/kg of the test substance.
Clinical signs:
No clinical abnormalities were observed at anytime during the observation period.
Body weight:
One 2000 mg/kg female rat gained weight during the first week of the study but lost a small amount of weight (6.46 grams) during the second week of the study. This female rat gained weight over the 14-day observation period. All other rats gained weight during both weeks of the study.
Gross pathology:
No test substance-related changes were observed at necropsy and no tissue was collected for microscopic examination.

Applicant's summary and conclusion

Interpretation of results:
other: Not classified in accordance with EU criteria
Conclusions:
Under the conditions of the test, the acute oral LD50 of the test substance was determined to be greater than 2000 mg/kg for female rats.
Executive summary:

In a GLP compliant study conducted in line with OECD Guideline 420 and EU Method B.1 bis, the acute toxicity of butanoic acid, 4-[[4-[7-chloro-6-(1,1-dimethylethyl)-3H-pyrazolo[1,5-b][1,2,4]triazol-2-yl]phenyl]amino]-4-oxo, tetradecyl ester to female rats was investigated.

An initial dose of 300 mg/kg of the test substance was administered to a single female rat. Since no signs of toxicity were noted for this female, a limit dose of 2000 mg/kg was administered to a second female rat. Since no signs of toxicity were noted for the 2000 mg/kg female, an additional four female rats were administered the limit dose.

For the five female rats that were administered the limit dose, the test substance was administered as a 20 % suspension in an aqueous carboxymethylcellulose vehicle solution. No mortality or abnormal clinical signs were observed for the 300 or 2000 mg/kg dose groups at any time during the 14-day observation period. One 2000 mg/kg female rat lost a small amount of weight (6.46 grams) during the second week of the study. However, this female rat gained weight over the 14-day observation period. All other rats gained weight during both weeks of the study. No test substance-related changes were observed at necropsy and no tissues

were collected for histological examination.

The acute oral LD50 for this test substance was greater than 2000 mg/kg for female rats and requires no toxicity classification under current EU requirements.