Registration Dossier

Toxicological information

Skin sensitisation

Currently viewing:

Administrative data

Endpoint:
skin sensitisation: in vivo (non-LLNA)
Type of information:
experimental study
Adequacy of study:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
data from handbook or collection of data
Justification for type of information:
data is from peer reviewed journals

Data source

Reference
Reference Type:
publication
Title:
The Freund's Complete Adjuvant Test and the Open Epicutaneous Test
Author:
G. Klecak
Year:
1985
Bibliographic source:
Curr. Probl. Derm., vol.14, pp.152-171 (Karger, Basel 1985)

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
other: FREUND'S COMPLETE ADJUVANT (FCAT)
Principles of method if other than guideline:
An Open Epicutaneous Test (OET) was performed on guinea pigs to assess the skin sensitization potential of the test chemical
GLP compliance:
not specified
Type of study:
Freund's complete adjuvant test
Justification for non-LLNA method:
not specified

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
liquid
Details on test material:
- Name of test material (as cited in study report): Isopulegol- Molecular formula: C10H18O- Molecular weight : 154.2512 g/mol- Substance type: Organic- Physical state: Liquid

In vivo test system

Test animals

Species:
guinea pig
Strain:
other: Himalayan white-spotted
Sex:
male/female
Details on test animals and environmental conditions:
Weight at study initiation: 300-450 g

Study design: in vivo (non-LLNA)

Induction
Route:
epicutaneous, open
Vehicle:
unchanged (no vehicle)
Concentration / amount:
0.1 ml
Day(s)/duration:
3 weeks
Adequacy of induction:
not specified
Challenge
No.:
#1
Route:
epicutaneous, open
Vehicle:
unchanged (no vehicle)
Concentration / amount:
0.025ml of the minimal irritating concentration
Day(s)/duration:
on days 21 and 35
Adequacy of challenge:
other: The minimal irritating concentration of each material was used to confirm the biological activity determined before starting the induction and to exclude false results based on instability of test material
No. of animals per dose:
30 (20: test group ; 10: control group)
Details on study design:
RANGE FINDING TESTS: The pretest was performed to determine the primary irritating threshold concentration of test substances at various concentrations (100, 30, 10 and 3%). In this test, a single application of 0.025 ml of each test concentration was simultaneously performed on one of the areas measuring 2 cm2 of the flank skin previously clipped and marked with a circular stamp. Reactions are read 24 h after the application of the test material. MAIN STUDYA. INDUCTION EXPOSURE- No. of exposures: 21- Exposure period:24 hours- Test groups:6-8 guinea pigs- Control group: 6 to 8 untreated controls- Site: an area measuring 8 cm2 on the clipped flank skin of the guinea pigs- Frequency of applications: The applications are repeated daily for 3 weeks or done 5 times weekly during 4 weeks- Duration: 21 days (3 weeks)- Concentrations:0.1mlB. CHALLENGE EXPOSURE- No. of exposures: 2- Day(s) of challenge: on days 21 and 35- Exposure period:24 hours- Test groups: 6-8 guinea pigs- Control group: 6 to 8 untreated controls- Site: contralateral flank measuring 2 cm2- Concentrations: 0.025ml of minimal irritating concentration - Evaluation (hr after challenge): 24,48 and/or 72h.
Challenge controls:
yes concurrent vehicle control
Positive control substance(s):
not specified

Results and discussion

In vivo (non-LLNA)

Results
Reading:
1st reading
Hours after challenge:
72
Group:
test group
Dose level:
0.025ml of the minimal irritating concentration
No. with + reactions:
0
Total no. in group:
20
Clinical observations:
Negative results were observed in treated groups.
Remarks on result:
no indication of skin sensitisation

Applicant's summary and conclusion

Interpretation of results:
other: not sensitizing
Conclusions:
The test chemical failed to induce dermal sensitization reactions in guinea pigs after the challenge exposure.Hence, the test chemical can be considered to be not sensitizing.
Executive summary:

Open Epicutaneous test was conducted in guinea pigs (male and female) to determine the skin sensitization potential of the test chemical.

The pretest was performed to determine the primary irritating threshold concentration of test substances at various concentrations (e.g, 100, 30, 10 and 3%). In this test, a single application of 0.025 ml of each test concentration was simultaneously performed on one of the areas measuring 2 cm2 of the flank skin previously clipped and marked with a circular stamp. Reactions are read 24 h after the application of the test material.

 

On day 1 during induction, 0.1 ml of undiluted test chemical was applied to an area measuring 8 cm2 on the clipped flank skin of the guinea pigs. The applications are repeated daily for 3 weeks or done 5 times weekly during 4 weeks, usually on the same skin sites. The application sites were left uncovered and the reactions, if continuous daily applications were performed, can be read 24 h after each application, or at the end of each week.

 

To determine whether or not contact sensitization was induced, all groups of guinea pigs previously treated for 21 days, as well as 10 untreated, or only pretreated with the vehicle, controls are tested on days 21 and 35 on the contralateral flank with the test material. This test was performed by applying with a pipette 0.025 ml of chemical to skin areas measuring 2 cm2. The reactions were read after 24, 48 and/or 72h.

 

The test chemical failed to induce dermal sensitization reactions in guinea pigs after the challenge exposure.

Hence,the test chemical can be considered to be not sensitizing.