Registration Dossier

Toxicological information

Skin sensitisation

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Administrative data

Endpoint:
skin sensitisation: in vivo (non-LLNA)
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: GLP Guideline study. Reliability of 2 given since the data is based on read across, not the target substance.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1990
Report Date:
1990

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 406 (Skin Sensitisation)
GLP compliance:
yes
Type of study:
guinea pig maximisation test
Justification for non-LLNA method:
A valid guinea pig maximisation test was already available. It was considered un-ethical to re-run to the LLNA method

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Test material form:
liquid

In vivo test system

Test animals

Species:
guinea pig
Strain:
Himalayan
Sex:
female
Details on test animals and environmental conditions:
- Source:  BRL, Fuellingsdorf, Switzerland
- Age at study initiation: 8 weeks
- Weight at study initiation: 324 - 342 g (mean)
- Diet: ad libitum
- Water: ad libitum
- Acclimation period:



Study design: in vivo (non-LLNA)

Inductionopen allclose all
Route:
intradermal and epicutaneous
Vehicle:
physiological saline
Concentration / amount:
Range finding tests: intradermal (1, 3, 5 %); dermal (25, 50, 75, 100 %)
Induction: intradermal (5 % in saline and 5 % in Saline/FCA); dermal (25, 50, 75,100 %)
Challenge: dermal (25 %)
Challengeopen allclose all
Route:
epicutaneous, occlusive
Vehicle:
physiological saline
Concentration / amount:
Range finding tests: intradermal (1, 3, 5 %); dermal (25, 50, 75, 100 %)
Induction: intradermal (5 % in saline and 5 % in Saline/FCA); dermal (25, 50, 75,100 %)
Challenge: dermal (25 %)
No. of animals per dose:
40 femals in total and additional 6 females for pretests;
10 animals for control group 1
10 animals for control group 2
20 animals for test group
2 females for the  intracutaneous pretest  
4 females for the epicutaneous pretest.
Details on study design:
For the identification of irritant test substance concentration suitable for the induction phase, intradermal injections (0.1 mL/site) were made into the clipped flank of 2 animals at concentrations of 1, 3 and 5 % dissolved in physiological saline. The dermal reactions were assessed 24 hours later.  For epidermal applications patches of filter paper (2 x 2 cm) were saturated with the undiluted test substance (100 %) and with preparations in physiological saline of 25, 50, 75 % and were applied occlusively to  the clipped and shaved skin of 4 animals. The dressings were removed  after 24 hours and investigated for erythema and edema and  re-investigated after 48 hours.

MAIN STUDY
A1. INDUCTION EXPOSURE (intrademal injections)
- No. of exposures: 3 pairs of intradermal injections (0.1 mL/site)
- Exposure period: 24 hours
- Test groups: 1) Freund's complete adjuvant 50:50 with bi-distilled water.
2) The test article, diluted to 5 % with physiological saline.
3) The test article at the concentration used in (2), emulsified in a 50:50 mixture of Freund's complete adjuvant and the vehicle ued i n (2) .
- Control group: 1) Freund's complete adjuvant 50:50 with bi-distilled water.
2) Vehicle used in (2) for test group .
3) Freund's complete adjuvant 50:50 with bi-distilled water.
- Site: clipped dorsal skin
- Frequency of applications:
- Duration: 24 h after injections reactions were assessed


A2. INDUCTION EXPOSURE (epidermal application)
- No. of exposures: single exposure with Patches of 2 x2 cm in size saturated with the test compound at different concentrations
- Exposure period: 24 hours
- Frequency of applications: epicutaneous application was made one week after intradermal induction
- Duration: 72 h (24h exposure, then substance removal and first reading; second and third readings 24h and 48h after substance removal)
- Concentrations: 100, 75, 50, 25 %


B. CHALLENGE EXPOSURE
- No. of exposures: 2 patches of 2 x2 cm in size saturated with the test compound were applied to the right and the left flank skin
- Day(s) of challenge: two weeks after the epidermal induction application
- Exposure period: 24 h
- Test groups: all test groups challenged with the test substance
- Control group: control group 1 challenged with the test substance, control group 2 left untreated
- Site: shaved flank skin
- Concentrations: non-irritant concentration (25 % in saline)
- Evaluation (hr after challenge): immediately after patch removal, 24h and 48h later


OTHER: Scoring
The reactions were scored according to the following numerical grading system according to Draize:

Erythema and eschar formation:
0        No erythema
1        Very slight erythema (barely perceptible)
2        Well-defined erythema
3        Moderate to severe erythema
4        Severe erythema (beet redness) to slight eschar formation (injuries in  depth)

Edema formation:
0        No edema
1        Very slight edema (barely perceptible)
2        Slight edema (edges of area well-defined by definite raising)
3        Moderate edema (raised approximately 1 mm)
4        Severe edema (raised more than 1 mm and extending beyond the area of  exposure)
Challenge controls:
1) Freund's complete adjuvant 50:50 with bi-distilled water.
2) Vehicle used in (2) for test group.
3) Freund's complete adjuvant 50:50 with bi-distilled water.

Results and discussion

In vivo (non-LLNA)

Resultsopen allclose all
Reading:
1st reading
Hours after challenge:
24
Group:
test group
No. with + reactions:
2
Total no. in group:
20
Clinical observations:
erythema
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. No with. + reactions: 2.0. Total no. in groups: 20.0. Clinical observations: erythema.
Reading:
2nd reading
Hours after challenge:
48
Group:
test group
No. with + reactions:
1
Total no. in group:
20
Clinical observations:
erythema
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. No with. + reactions: 1.0. Total no. in groups: 20.0. Clinical observations: erythema.
Reading:
1st reading
Hours after challenge:
24
Group:
negative control
No. with + reactions:
0
Total no. in group:
10
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. No with. + reactions: 0.0. Total no. in groups: 10.0.
Group:
positive control
Remarks on result:
not measured/tested

Any other information on results incl. tables

Results of pretest:  
Based on the reactions of the pretest, the concentration of 5% was selected for intradermal injection for the main study

Based on the reactions of the pre-test with regards to epidermal application, the concentration selected for the induction was 75 % and for  the challenge procedure was 25 %.

Results of main test:
 
No mortalities or toxic signs occurred.

Control group:
No positive skin reactions were evident after 1st challenge neither with when treated with physiological saline nor with 25 % Diethanolamine.

Test group:
Only 2/20 (10 %) showed erythema findings at 24 h readings, declining to 1/20 (5 %) at 48 h reading when treated with 25 % Diethanolamine. No further findings were noted.

Summary of skin reactions after challenge exposure:

Readings:

24 h

48 h

Control groups

75 % epidermal DEA during induction     

0/10

0/10

Phys. Saline during induction        

0/10

0/10

Test group

25 % DEA

2/20

1/20

Phys. saline

0/20

0/20


                                         
Body weights:

The body weight gain of the animals was not affected adversely during the study.

Systemic Symptoms:

No systemic symptoms were observed during the study.

Applicant's summary and conclusion

Interpretation of results:
other: GHS criteria not met
Conclusions:
Not skin sensitising
Executive summary:

The potential of the test material to cause skin sensitisation was investigated in a guinea-pig maximisation test conducted in accordance with the standardised guideline OECD 406 under GLP conditions.

Twenty female Himalayan guinea-pigs were exposed to the test material. The concentrations used in the induction phase of the study were 5 % in saline and 5 % in saline/FCA for the intradermal and 25, 50, 75 and 100 % in physiological saline for the topical application.

In the challenge application, the animals were exposed to the test material at 25 % v/v in physiological saline.

No signs of ill health or toxicity were observed throughout the study. The test material elicited dermal reactions similar to those seen in the control animals.

Under the conditions of this study, the test material did not produce evidence of skin sensitisation and therefore requires no classification in accordance with EU criteria.