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Diss Factsheets

Administrative data

Endpoint:
skin sensitisation: in vivo (non-LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1988-03-15 to 1988-05-02
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: OECD guideline study, GLP

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1988
Report date:
1988

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 406 (Skin Sensitisation)
Deviations:
no
GLP compliance:
yes
Type of study:
guinea pig maximisation test

Test material

Constituent 1
Chemical structure
Reference substance name:
Iso(C10-C14)alkyl (3,5-di-tert-butyl-4-hydroxyphenyl)methylthioacetate
EC Number:
404-800-4
EC Name:
Iso(C10-C14)alkyl (3,5-di-tert-butyl-4-hydroxyphenyl)methylthioacetate
Cas Number:
118832-72-7
Molecular formula:
C30H52O3S
IUPAC Name:
11-methyldodecyl 2-{[(3,5-di-tert-butyl-4-hydroxyphenyl)methyl]sulfanyl}acetate
Details on test material:
- Physical state: liquid
- Analytical purity: commercial grade
- Storage condition of test material: room temperature

In vivo test system

Test animals

Species:
guinea pig
Strain:
other: Pirbright White
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: CIBA-GEIGY LTD. Tierfarm, 4334 Sisseln, Switzerland
- Age at study initiation: Approx. 10 weeks
- Weight at study initiation: 336 to 430 g
- Housing: individually in Macrolon cages (Type 3)
- Diet: ad libitum standard guinea pig pellets NAFAG No. 846, Gossau SG
- Water: tap water, ad libitum
- Acclimation period: 8 days

ENVIRONMENTAL CONDITIONS
- Temperature: 22 +/- 3°C
- Humidity: 30 to 70%
- Photoperiod: 12 hrs light cycle

Study design: in vivo (non-LLNA)

Inductionopen allclose all
Route:
intradermal and epicutaneous
Vehicle:
other: vaseline (epicutaneous), sesame oil (intradermal)
Concentration / amount:
Intradermal Induction: test substance in sesame oil and adjuvant mixture: 1%
Epidermal Induction: test substance 30 % in vaseline
Epidermal Challenge: test substance 3 % in vaseline
Challengeopen allclose all
Route:
epicutaneous, occlusive
Vehicle:
other: vaseline (epicutaneous), sesame oil (intradermal)
Concentration / amount:
Intradermal Induction: test substance in sesame oil and adjuvant mixture: 1%
Epidermal Induction: test substance 30 % in vaseline
Epidermal Challenge: test substance 3 % in vaseline
No. of animals per dose:
10 male and 10 female guinea pigs
Details on study design:
INDUCTION (weeks 1 and 2)
The induction was a two-stage operation. First, intradermal injections (into the neck region), secondly, closed patch exposure over the injection sites one week later. Three pairs of intradermal injections (0.1 ml per injection) were made simultaneously into the shaved neck of the guinea pigs as follows:
- adjuvant and saline (1:1)
- test compound in sesame oil
- test compound in the adjuvant saline mixture
One week later the test substance was incorporated in vaseline and applied on a filter paper patch to the neck of the animals (patch 2 x 4 cm - occluded administration for 48 hours). Dose of application: approx. 0.4 g paste of 30 % test substance in vaseline

CHALLENGE
Two weeks after the epidermal induction application the animals were tested on the flank with the test substance in vaseline and the vehicle alone (patch 2 x 2 cm,- occluded administration for 24 hours). Dose of application: approx. 0.2 g paste of 3 % test article in vaseline. The concentrations of the test compound for the induction and challenge periods were determined on separate animals.

OTHER
Separate animals were treated with the test substance for the evaluation of the primary irritation threshold concentration. Concentrations of 1, 3, 10 and 30 % in vaseline were tested. Erythema reactions were observed at 10 and 30 %. No erythema was induced at the lower concentrations. Therefore, 3 % was used as the maximum subirritant concentration for the challenge application.
Challenge controls:
A control group was treated with adjuvant and the vehicle during the induction period. During the challenge period the group was treated with the vehicle as well as with the test article (at least 10 animals) to check the maximum subirritant concentration of the test article in adjuvant treated animals.
Positive control substance(s):
no

Results and discussion

In vivo (non-LLNA)

Resultsopen allclose all
Reading:
1st reading
Hours after challenge:
24
Group:
test chemical
Dose level:
3% test substance in vaseline
No. with + reactions:
3
Total no. in group:
20
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 3% test substance in vaseline. No with. + reactions: 3.0. Total no. in groups: 20.0.
Reading:
1st reading
Hours after challenge:
24
Group:
negative control
Dose level:
3% test substance in vaseline
No. with + reactions:
0
Total no. in group:
20
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. Dose level: 3% test substance in vaseline. No with. + reactions: 0.0. Total no. in groups: 20.0.
Reading:
2nd reading
Hours after challenge:
48
Group:
test chemical
Dose level:
3% test substance in vaseline
No. with + reactions:
3
Total no. in group:
20
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 3% test substance in vaseline. No with. + reactions: 3.0. Total no. in groups: 20.0.
Reading:
2nd reading
Hours after challenge:
48
Group:
negative control
Dose level:
3% test substance in vaseline
No. with + reactions:
0
Total no. in group:
20
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: negative control. Dose level: 3% test substance in vaseline. No with. + reactions: 0.0. Total no. in groups: 20.0.

Applicant's summary and conclusion

Executive summary:

A skin sensitisation test in Pirbright White guinea pigs was performed according to OECD 406 (Maximisation test according to Magnusson and Kligman). The test was performed on 10 male and 10 female guinea pigs in the test group and 10 males and 10 females in the control group. The induction was a two-stage operation. First, three pairs of intradermal injections (0.1 ml per injection) were made simultaneously into the shaved neck of the guinea pigs as follows:

- adjuvant and saline (1:1)

- test compound in sesame oil

- test compound in the adjuvant saline mixture

One week later the test substance was incorporated in vaseline and applied on a filter paper patch to the neck of the animals (patch 2 x 4 cm - occluded administration for 48 hours; 0.4 g paste of 30 % test substance in Vaseline). Two weeks after the epidermal induction application the animals were tested on the flank with the test substance in vaseline and the vehicle alone (patch 2 x 2 cm,- occluded administration for 24 hours; approx. 0.2 g paste of 3 % test article in vaseline). A control group was treated with adjuvant and the vehicle during the induction period. During the challenge period the group was treated with the vehicle as well as with the test article (at least 10 animals) to check the maximum subirritant concentration of the test article in adjuvant treated animals. The concentrations of the test compound for the induction and challenge periods were determined on separate animals. 15 % of the animals were sensitized in this guinea pig maximization test (according to Magnusson and Kligman). The substance is therefore considered to have little or no skin sensitizing potential.