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Toxicological information

Skin irritation / corrosion

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Administrative data

Endpoint:
skin irritation: in vivo
Type of information:
experimental study
Adequacy of study:
key study
Study period:
9 September 2003 to 12 September 2003
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2003
Report Date:
2003

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 404 (Acute Dermal Irritation / Corrosion)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method B.4 (Acute Toxicity: Dermal Irritation / Corrosion)
Deviations:
no
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
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:
rabbit
Strain:
New Zealand White
Details on test animals and environmental conditions:
TEST ANIMALS
- Age at study initiation: The rabbits were young adults (at least three months old)
- Weight at study initiation: at least 2000 grams
- 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 rabbits were singly housed in suspended, stainless-steel mesh cages. Cages and racks were washed once a week. Absorbent paper, used to collect excreta, was changed every other day.
- Diet: Certified High Fiber Rabbit Diet 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: 21.4 to 23.0 °C
- Humidity: 45.1 to 61.4 %
- Photoperiod: A photoperiod of 12 hours of light was maintained.

Test system

Type of coverage:
occlusive
Preparation of test site:
shaved
Vehicle:
water
Controls:
other: No control substance was used. Adjacent areas of untreated skin of each animal served as control sites for the test areas.
Amount / concentration applied:
TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 gram of the test substance was applied topically to each animal. The test substance was administered as a solid moistened with water.

Duration of treatment / exposure:
4 hours
Observation period:
The site of application was examined at 1, 24, 48, and 72 hours after removal of the occlusive patch. Observations included estimation of erythema, edema, necrosis, eschar formation, scarring, erosion, and staining caused by the test substance as well as general systemic effects.
Number of animals:
3
Details on study design:
TEST SITE
- Area of exposure: Not reported
- % coverage: Not reported
- Type of wrap if used: A fiber pad and an occlusive wrap to hold the test substance in place for four hours.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): At the end of the exposure period, the application site was rinsed with running water.
- Time after start of exposure: 4 hours

SCORING SYSTEM:
The most severely affected area within the test substance application sites were scored for dermal reactions. Corrosion was considered to have resulted if destruction or irreversible alteration of the skin tissue (ulceration and/or necrosis) resulted after an exposure of 4 hours or less to the test substance. Skin irritation reactions were graded and scored as described in below:

Grading Of Skin Reactions*

Erythema and Eschar Formation
0 = No erythema
1 = Very slight erythema (barely perceptible)
2 = Well-defined erythema
3 = Moderate to severe erythema
4 = Severe erythema to slight eschar formation

Edema Formation
0 = No edema
1 = Very slight edema (barely perceptible)
2 = Slight edema (edges of area well defined by definite raising)
3 = Moderate edema (edges raised approximately 1.0 mm)
4 = Severe edema (raised more than 1.0 mm and extending beyond area of exposure)

*Graded as described in OECD Guideline 405 (Annex V., Test B.4) (Grading of Skin Reaction)

Results and discussion

In vivo

Resultsopen allclose all
Irritation parameter:
erythema score
Basis:
mean
Time point:
24/48/72 h
Score:
0
Max. score:
0
Reversibility:
other: no effects seen
Irritation parameter:
edema score
Basis:
mean
Time point:
24/48/72 h
Score:
0
Max. score:
0
Reversibility:
other: no effects seen
Irritant / corrosive response data:
No irritant response or serious lesion was noted during the 72-hour observation period.
Other effects:
No toxic effects were noted during the study.

Any other information on results incl. tables

Observations for Irritation

The application site of each animal was examined for signs of irritation at 1, 24, 48, and 72 hours after termination of exposure to the test substance. Observations for irritation (erythema and edema) are presented in Table 1.

Table 1: Response at application site

Animal number Erythema, edema*
1 hour 24 hours 48 hours  72 hours
745 0,0 0,0 0,0 0,0
746 0,0 0,0 0,0 0,0
747 0,0 0,0 0,0 0,0

*Graded as described in OECD Guideline 405 (Annex V., Test B.4) (Grading of Skin Reaction)

Applicant's summary and conclusion

Interpretation of results:
other: Not classified in accordance with EU criteria
Conclusions:
Under the conditions of the test, the substance was determined to be a non-irritant to the skin.
Executive summary:

In a GLP compliant study conducted in line with OECD Guideline 404 and EU Method B.4, the dermal irritation 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 was investigated by administering single topical doses of 0.5 gram of the test substance to rabbits. The test substance was left in contact with the skin under an occlusive wrap for four hours. Skin lesions were graded according to OECD Guideline 404 (Annex V., Test B.4).

No irritant response or serious lesion was noted during the 72-hour observation period. Based on these results, the test substance requires no skin irritation classification in line with current EU requirements.