2-methylpropyl-(R)-2-hydroxypropanoate

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: OECD Guideline Study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1991

Report date:

1991

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

GLP compliance:

yes

Remarks:

Centre International de Toxicologie, France

Type of study:

Buehler test

Test material

Test material information

Constituent 1

Reference substance name:

2-methylpropyl-(R)-2-hydroxypropanoate

EC Number:

407-770-0

EC Name:

2-methylpropyl-(R)-2-hydroxypropanoate

Cas Number:

61597-96-4

Molecular formula:

C7 H14 O3

IUPAC Name:

2-methylpropyl-(R)-2-hydroxypropanoate

Details on test material:

- Name of test material (as cited in study report): D-(+)-Isobutyllactat
- Physical state: liquid
- Analytical purity: 99.5%
- Isomers composition: D/(D+L) = 99.4%
- Lot/batch No.: PR 596
- Storage condition of test material: 4°C

In vivo test system

Test animals

Species:

guinea pig

Strain:

Dunkin-Hartley

Sex:

male/female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Shamrock Bio Service breeding centre (78950 Gambais, France)
- Weight at study initiation: mean: 333 ± 10 g for males and 335 ± 18 for females
- Housing: single
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: at least 5 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 ± 3
- Humidity (%): 50 ± 20
- Photoperiod (hrs dark / hrs light): 12/12

Study design: in vivo (non-LLNA)

Induction

Induction 1

Route:

epicutaneous, occlusive

Vehicle:

unchanged (no vehicle)

Induction 2

Concentration / amount:

undiluted, 0.5 mL

Challenge

Challenge 1

Route:

epicutaneous, occlusive

Vehicle:

unchanged (no vehicle)

Challenge 2

Concentration / amount:

undiluted, 0.5 mL

No. of animals per dose:

20

Details on study design:

RANGE FINDING TESTS: A preliminary test enabled to define the maximum non-irritant concentration (MNIC) by cutaneous application of 0.5 ml of the test substance in its original form to a clipped area of approximately 4 square cm. The test substance was prepared on a compress, applied to the skin and then held in place by means of an occlusive dressing for 6 hours. Twenty-four hours after application of the test substance no cutaneous reactions were observed with the test substance in its original form. The test substance was tested in its original form for the definitive study on a group of 20 animals (10 males and 10 females).

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 3
- Exposure period: 6 hours
- Test groups: 10 female and 10 males
- Control group: no control group
- Site: the anterior right and left flanks
- Frequency of applications: induction: d1, d8 and d15
- Duration: 6 hours
- Concentrations: 0.5 mL undiluted


B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Day(s) of challenge: d29
- Exposure period: 6 hours
- Test groups: 10 females and 10 males
- Control group: no control group
- Site: posterior right and left flanks
- Concentrations: 0.5 mL undiluted
- Evaluation (hr after challenge): 24 and 48

Results and discussion

In vivo (non-LLNA)

Results

Results 1

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

undiluted

No. with + reactions:

0

Total no. in group:

20

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: undiluted. No with. + reactions: 0.0. Total no. in groups: 20.0.

Results 2

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

undiluted

No. with + reactions:

0

Total no. in group:

20

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: undiluted. No with. + reactions: 0.0. Total no. in groups: 20.0.

Any other information on results incl. tables

Clinical signs: In one animal a decrease in the spontaneous activity accompanied by dyspnea and piloerection was noted between day 8 and day 18. Another animal was found dead on day 7 without preclinical signs. This was probably not related to the treatment, because it is frequently observed in guinea-pigs and due to spontaneous disease. No apparent abnormalities were observed at the macroscopic examination of the main organs of the animal found dead during the study.

Body weights: The body weight gain of the surviving animals was normal when compared with animals of the same age.

Cutaneous reaction: No cutaneous reactions were observed on day 2. No cutaneous reactions were observed 24 and 48 hours after the cutaneous challenge application of the test substance on days 30 and 31.

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information