Z-85

Skin sensitisation

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Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

27 July 2006 to 22 September 2006

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study was conducted following OECD Guideline 429 and EU Method B.42 with no deviations.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2006

Report date:

2006

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.42 (Skin Sensitisation: Local Lymph Node Assay)

GLP compliance:

yes (incl. QA statement)

Type of study:

mouse local lymph node assay (LLNA)

Test material

Reference

Name:

Unnamed

Type:

Constituent

Test material form:

liquid: viscous

Details on test material:

Description: Tan, viscous liquid
Storage: room temperature in the dark

See read-across justification in Section 13

In vivo test system

Test animals

Species:

mouse

Strain:

other: CBA/Ca

Sex:

female

Details on test animals and environmental conditions:

- mice were nulliparous and non-pregnant.
- acclimation period = 5 days
- indelible ink-marking on tail and cage card were used to identify each test animal
- individually housed with free access to food and water

Study design: in vivo (LLNA)

Vehicle:

acetone/olive oil (4:1 v/v)

Concentration:

5%, 10%, 25%

No. of animals per dose:

5

Details on study design:

RANGE FINDING TESTS:

Three mice were used for the preliminary screening test. The mice were treated daily for days 1-3 and 25 uL of undiluted test material and test material at concentrations of 50% and 25% v/v in acetone/olive oil 4:1 was applied to the dorsal surface of each ear. A concentration of 25% was the highest concentration that was predicted to not produce systemic toxicity or excessive local irritation.

MAIN STUDY

- Name of test method: ß-scintillation counting
- Criteria used to consider a positive response:
1. The increase in isotope incorporation for at least one concentration tested must be three-fold or more compared to the control (vehicle treated) mice.
2. The data generated must not be incompatible with the biological dose response.

TREATMENT PREPARATION AND ADMINISTRATION:

Samples were administered to the dorsum of both ears using a micro-pipette.
Groups of 5 mice were dosed with 25 µl of either vehicle (acetone/olive oil 4:1) or a 25%, 10%, or 5% preparation of the test item on three consecutive days on the dorsum of both ears. Five days after initial dosing the animals received approx. 20 µCi of 3H-methyl thymidine. The animals were sacrificed 5 h later and radioactive counts/lymph node were measured. The lymph nodes were measured as single cell suspensions.

The SI was calculated.

Statistics:

- ANOVA
- Dunnett's Mutltiple Comparison test and Dunnett's T3 Multiple Comparison Method were used to evaluate significant results for homogenous or heterogenous datasets, respectively.

Results and discussion

In vivo (LLNA)

Results

Results 1

Parameter:

other: disintegrations per minute (DPM)

Remarks on result:

other: see Remark

Remarks:

A comparison of the results and standard deviation between the control and test animals did not demonstrate any significant difference. The mean Dpm/Animal (Standard Deviation) is as follows for each group: Vehicle: 2241.76 (941.99) 5%: 2236.38 (1196.93) 10%: 2872.57 (1183.42) 25%: 5919.87 (2240.87)

Results 2

Key result

Parameter:

SI

Value:

1

Test group / Remarks:

5%

Results 3

Key result

Parameter:

SI

Value:

1.28

Test group / Remarks:

10%

Results 4

Key result

Parameter:

SI

Value:

2.64

Test group / Remarks:

25%

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The test material is considered to be a non-sensitizer under the conditions of the test.

Executive summary:

Test Guideline

OECD Guideline No. 429 and EC Method B42

Method and materials

A study was performed to assess the skin sensitization of the test material using LLNA. Female CBA/Ca mice were used for both the preliminary and the official study. The preliminary test used 3 animals at concentrations of 100%, 50%, and 25% test material v/v acetone/olive oil 4:1 as the vehicle. A concentration of 25% was the highest concentration that was predicted to not produce systemic toxicity or excessive local irritation and therefore, this was the highest concentration used in the study.

Following the preliminary screening test, four groups of 5 animals were treated with 50 uL (25 uL per ear) of either the vehicle (acetone/olive oil 4:1) alone or at concentrations of 25%, 10%, and 5% of the test material v/v in the vehicle.

Results

The Stimulation Index (SI) was calculated for each test group and was 1.00 (5%), 1.28 (10%), and 2.64 (25%).

Conclusion

The test material was considered to be a non-sensitizer under the conditions of the test.