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Toxicological information

Skin sensitisation

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Administrative data

Endpoint:
skin sensitisation
Remarks:
in vivo
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Acceptable, well documented study report which meets basic scientific principles.

Data source

Reference
Reference Type:
publication
Title:
Method for assessment of experimental allergy in guinea pigs adapted to cosmetic ingredients
Author:
K G DOSSOU, C SlCARD, G KALOPISSIS, D REYMOND, H SCHAEFER
Year:
1985
Bibliographic source:
Contact Dermatitis 1985: 13: 226-234

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
other: company guidline for testing cometic ingredients
Deviations:
no
Principles of method if other than guideline:
Method 1: open epidermal induction and challenge, the intensity of the reaction being maximized by injecting Freund's complete adjuvant into the foot pad
Method 2: quasi-intradermal induction: both the adjuvant and test substance are injected into the foot pad
GLP compliance:
not specified
Type of study:
other: modified guinea pig maximisation tests

Test material

Constituent 1
Reference substance name:
Automatically generated during migration to IUCLID 6, no data available
IUPAC Name:
Automatically generated during migration to IUCLID 6, no data available
Details on test material:
purity >=99%

In vivo test system

Test animals

Species:
guinea pig
Strain:
Hartley
Sex:
male/female
Details on test animals and environmental conditions:
Acclimatization: 1 week.
Husbandry: in groups of 12 (6 M and 6 F) or 24 (12 M and 12 F). For each experiment, there were 3 groups: 1 control. 1 topical route. 1 intradermal route. When necessary, 2 vehicle groups were added.
Room temperature: (22±2)°C
Relative humidity: (55±15)%.
Ventilation frequency: 13 cycles/h.
Food: C17-50 pellet diet from Extrii Labo.
Water: available ad libitum.
Cages: iron cages (54 x 42 x 20 cm), 3 animals / cage

Study design: in vivo (non-LLNA)

Inductionopen allclose all
Route:
other: Method 1: induction by topical route, Method 2: Induction by injection
Vehicle:
water
Concentration / amount:
Induction: 0.18 mmol/L
Challlenge: 0.09 mmol/L
Challengeopen allclose all
Route:
epicutaneous, open
Vehicle:
water
Concentration / amount:
Induction: 0.18 mmol/L
Challlenge: 0.09 mmol/L
No. of animals per dose:
12 (6 M and 6 F) or 24 (12 M and 12 F)
Details on study design:
For each experiment, there were 3 groups: 1 control. 1 topical route. 1 intradermal route. When necessary, 2 vehicle groups were added.

Method 1: Induction by topical route.
On day Dl, all animals received 0.2 ml of FCA injected in the foot pad of a hind leg. 6 h before any application, an area of 3 x 5 cm2 on the upper scapular region was shaved. Experimental group: on days Dl, D3 & D5, 0.5 ml of the test substance was applied to the shaved area at the same site (open application). Control group: the animals were exposed to the vehicle without the test agent.

Method 2: Induction by injection.
The injection was made with the test agent incorporated in FCA. Experimental group: on day D5, the animals received a single injection of the mixture[FCA/(vehicle 1+ test substance)] (1:1) into the foot pad of a hind leg, Control group: the animals were given the same injection, but without the lest substance (FCA/vehicle). From day D5 to D16, the animals received no treatment. On day D12 they were prepared for the challenge.

Challenge
The back of all animals, including controls, was shaved and depilated with wax. On day D16, the challenge applications were performed: open topical applications of 10 µL of the test substance on the lumbar region. The test agent was generally used at half the induction concentration. All animals including controls received the same challenge materials. Reactions were evaluated at 24 and 48 h (DI7 and D18).
Challenge controls:
All animals including controls received the same challenge materials.
Positive control substance(s):
yes
Remarks:
Formaldehyde, benzocaine, dinitro 2,4 chlorobenzene

Results and discussion

Positive control results:
Sensitization rate

Method 1 (Topical route):
DNCB: 100%
Formaldehyde: 20%
Benzocaine: 0%

Method 2 (Injection route):
DNCB: 100%
Formaldehyde: 80%
Benzocaine: 30%

In vivo (non-LLNA)

Resultsopen allclose all
Reading:
other: 24 and 48h
Group:
other: test group, method 1 (topical rout)
Dose level:
Induction: 0.18 mmol/L, Challange: 0.09 mmol/L
No. with + reactions:
7
Total no. in group:
24
Clinical observations:
sensitization rate: 30%
Remarks on result:
other: Reading: other: 24 and 48h. Group: other: test group, method 1 (topical rout). Dose level: Induction: 0.18 mmol/L, Challange: 0.09 mmol/L. No with. + reactions: 7.0. Total no. in groups: 24.0. Clinical observations: sensitization rate: 30%.
Reading:
other: 24 and 48h
Group:
other: test group method 2 (injection route)
Dose level:
Induction: 0.18 mmol/L, Challange: 0.09 mmol/L
No. with + reactions:
18
Total no. in group:
24
Clinical observations:
sensitization rate: 75%
Remarks on result:
other: Reading: other: 24 and 48h. Group: other: test group method 2 (injection route). Dose level: Induction: 0.18 mmol/L, Challange: 0.09 mmol/L. No with. + reactions: 18.0. Total no. in groups: 24.0. Clinical observations: sensitization rate: 75%.

Any other information on results incl. tables

The % of sensitized (sensitization rate) animals is determined: those showing a reaction greater than that of the controls at least once in the two readings, are considered sensitized. The number of animals with + reactions is not given in the publication and was calculated based on the sensitization rate for group level of 24 animals.

Applicant's summary and conclusion

Interpretation of results:
sensitising
Remarks:
Migrated information
Conclusions:
Based on the findings of this study the test substance was considered to be a skin sensitizer.
Executive summary:

o-phenylenediamine was tested to predict and assess allergic reactions after application. The first method is an open epidermal induction and challenge, the intensity of the reaction being maximized by injecting Freund's complete adjuvant into the foot pad. The second method allows detection of weaker allergens and is a quasi-intradermal induction: both the adjuvant and test substance are injected into the foot pad. In both protocols, the challenge consisted of a single topical application in the lumbar region of 10 µL of test substance. Following these protocols the sensitization rate for the open epidermal induction was 30% and for the intradermal induction 75%. Based on the findings of this study the test substance was considered to be a skin sensitizer.

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