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Skin sensitisation

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Administrative data

Endpoint:
skin sensitisation: in vivo (non-LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Study period:
9 March 1983 - 9 April 1983
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1983
Report date:
1983

Materials and methods

Test guideline
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 406 (Skin Sensitisation)
GLP compliance:
not specified
Type of study:
guinea pig maximisation test
Justification for non-LLNA method:
The Sensitization test with Isobutavan in Guinea pigs (maximization test) was already available (performed in 1983) and reliable to evaluate the skin sensitization potential and the classification determination as _ klimish 1 study.

Test material

Constituent 1
Chemical structure
Reference substance name:
4-formyl-2-methoxyphenyl isobutyrate
EC Number:
243-956-6
EC Name:
4-formyl-2-methoxyphenyl isobutyrate
Cas Number:
20665-85-4
Molecular formula:
C12H14O4
IUPAC Name:
4-formyl-2-methoxyphenyl isobutyrate
Test material form:
other: liquid
Specific details on test material used for the study:
- Name of test material (as cited in study report): Isobutavan Y-09607, No. 211234, dated 13.12.1982
- Physical state: slightly yellow viscous liquid
- Received at laboratory on February 23, 1983

In vivo test system

Test animals

Species:
guinea pig
Strain:
not specified
Sex:
male
Details on test animals and environmental conditions:
The 15 male guinea pigs (body weight 361 g - 524 g) to be used of the main test were received on February 23, 1983. The acclimatation period was 14 days.

Study design: in vivo (non-LLNA)

Inductionopen allclose all
Route:
intradermal
Vehicle:
other: Freund's Complete Adjuvant (FCA)
Concentration / amount:
2 injections 0.1 ml
Route:
intradermal
Vehicle:
propylene glycol
Concentration / amount:
2 injections (0.1 ml) of a 10% dilution (v/v) of Isobutavan
Route:
intradermal
Vehicle:
other: FCA and PG (1:1)
Concentration / amount:
2 injections (0.1 ml) of a 10% dilution (v/v) of isobutavan in FCA and PG (1:1)
Route:
other: Topycal application, oclusive
Vehicle:
other: vaseline
Concentration / amount:
The animal were treated with a 25% dilution (w/w) of Isobutavan in vaseline
Day(s)/duration:
48 hours
Challengeopen allclose all
No.:
#1
Route:
other: topical application, oclusive
Vehicle:
other: vaseline
Concentration / amount:
10% dilution (w/w) of Isobutavan in vaseline
Day(s)/duration:
24 hours
No.:
#2
Route:
other: topical application, occlusive
Vehicle:
other: vaseline
Concentration / amount:
2.5% dilution (w/w) of Isobutavan in vaseline
No. of animals per dose:
15 animals were treated
Details on study design:
One week after the intradermal injections, the induction by topical appication was made in the same shoulder region.
The challenge was carried out two weeks after the topical induction in both test and control animals.
Challenge controls:
The challenge was carried out two weeks after the topical induction in both test and control animals. The right flank of all animals were topically treated.
Since upon, the challenge treatment a few test animals showed a very weak positive reaction a rechallenge was carried out in vaseline at a virgin site (left flank), 7 days later and assessed at 0, 24 and 48 hours.
Positive control substance(s):
yes

Results and discussion

In vivo (non-LLNA)

Resultsopen allclose all
Reading:
1st reading
Hours after challenge:
0
Group:
test chemical
Dose level:
10% dilution in vaseline
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
very slight erythema in 8 of the 10 animals visible imeediately after patch removal
Key result
Reading:
2nd reading
Hours after challenge:
24
Group:
test chemical
Dose level:
10% dilution in vaseline
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
very slight erythema in 8 of the 10 animals visible imeediately after patch removal
Reading:
2nd reading
Hours after challenge:
48
Group:
test chemical
Dose level:
10% dilution in vaseline
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
ery slight erythema in 8 of the 10 animals visible imeediately after patch removal

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
Conclusions:
The resultd obtained in a challenge with a 10% dilution (judgement at 24h after patch removal of the dressing (as recommended by the Magnusson and Kligman method) showed a very weak evidence of delayed hypersensitivity in only ne animal test. The challenge treatment with 2.5% dilution - that is a concentration four times lower than the non irritant concentration - did not elicit any sensitization reaction under the test conditions.
Executive summary:

The test substance Isobutavan was examined for possible sensitization potential by a maximization test in Guinea pigs. From the reaction to the challenge treatment with a 10% dilution of the test substance in vaseline, it was concluded that the test substance produced a very weak evidence of delayed hypersensitivity in only one test animal.

A 2.5% dilution of Isobutavan did not elicit sensitization reactions in the guinea pigs under the conditions of the test.