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Skin sensitisation

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Administrative data

Endpoint:
skin sensitisation: in vivo (non-LLNA)
Type of information:
other: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Study period:
From October 22, 1991 to January 14, 1992
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study
Remarks:
The complete read across justification is detailed in section 13. Source study has reliability 1.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1992
Report date:
1992

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
OECD Guideline 406 (Skin Sensitisation)
Version / remarks:
1981
Deviations:
no
Qualifier:
according to guideline
Guideline:
EU Method B.6 (Skin Sensitisation)
Version / remarks:
1984
Deviations:
no
GLP compliance:
yes (incl. QA statement)
Type of study:
guinea pig maximisation test
Justification for non-LLNA method:
Guinae pig maximisation test was available.

Test material

Constituent 1
Reference substance name:
Similar Substance 02
IUPAC Name:
Similar Substance 02
Test material form:
solid: particulate/powder

In vivo test system

Test animals

Species:
guinea pig
Strain:
other: Himalayan spotted
Sex:
female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: BRL, Biological Research Laboratories Ltd., Wölferstrasse 4, CH-4414 Füllinsdorf
- Age at study initiation: 7 - 8 weeks
- Weight at study initiation: control and test group (393 - 502 g), pretest (402-473 g)
- Housing: individually in Makrolon type-3 cages (size: 27 x 42 x 15 cm) with standard softwood bedding ("Lignocel")
- Diet: pelleted standard Kliba 342 (ad libitum)
- Water: tap water (ad libitum); once weekly additional supply of ascorbic acid (1 g/L via the drinking water)
- Acclimation period: one week under test conditions

ENVIRONMENTAL CONDITIONS
- Temperature: 22 ± 3 °C
- Humidity: 40-70 %
- Air changes: 10-15 per hr
- Photoperiod: 12/12 hrs dark/hrs light

Study design: in vivo (non-LLNA)

Induction
Route:
intradermal and epicutaneous
Vehicle:
other: physiol. saline (intradermal), vaselinum album (epidermal)
Concentration / amount:
5 % in physiol. saline
25 % in vaselinum album
Challenge
Route:
epicutaneous, occlusive
Vehicle:
other: vaselinum album
Concentration / amount:
25 % in vaselinum album
No. of animals per dose:
Control group: 10
Test group: 20
Details on study design:
RANGE FINDING TEST
For the intracutaneous pretest, 2 females were used; for the epicutaneous pretest, 4 females were used.
A. Intradermal injections
- 5, 3 and 1 % of test substance in physiol. saline
- site: flank
- dermal reactions were assessed 24 hours later

B. Epidermal applications
- 25, 15, 10 and 5 % of test substance in vaselinum album
- site: flank
- exposure period: 24 hours
- examination was performed 24 and 48 hours after removal of the dressing

MAIN STUDY
A.1. INDUCTION EXPOSURE (intradermal): day 0
- No. of exposures: 3 pairs of intradermal injections (0.1 ml/site) were made
- Test groups: Freund's complete adjuvant 50:50 with physiol. saline, 5 % test substance in physiol. saline, 5 % test substance in a mixture of Freund's complete adjuvant and physiol. saline (50:50)
- Control group: Freund's complete adjuvant 50:50 with physiol. saline, physiol. saline, Freund's complete adjuvant 50:50 with physiol. saline
- Site: area of dorsal skin from the scapular region
- Frequency of applications: single injection

A.2. INDUCTION EXPOSURE (epidermal); day 8
- Test group: 25 % of the test substance in vaselinum album
- Control group: vaselinum album only
- Site: the injection sites of the test animals
- Duration: 48 hours

B. CHALLENGE EXPOSURE; 2 weeks after the epidermal induction application (day 22)
- No. of exposures: 1
- Exposure period: 24 hours
- Test groups: left flank: 25 % test substance in vaselinum album, right flank: vaselinum album only
- Control group: treated in the same way as described at the test group
- Site: flank
- Evaluation (hr after challenge): 24 and 48


Challenge controls:
yes
Positive control substance(s):
yes
Remarks:
formaldehyde

Results and discussion

Positive control results:
8 of 10 animals showed skin reactions 24 h and 48 h after removing the dressings.

In vivo (non-LLNA)

Resultsopen allclose all
Reading:
1st reading
Hours after challenge:
24
Group:
negative control
Dose level:
0%
No. with + reactions:
0
Total no. in group:
10
Remarks on result:
no indication of skin sensitisation
Reading:
2nd reading
Hours after challenge:
48
Group:
negative control
Dose level:
0%
No. with + reactions:
0
Total no. in group:
10
Remarks on result:
no indication of skin sensitisation
Reading:
1st reading
Hours after challenge:
24
Group:
negative control
Dose level:
25%
No. with + reactions:
0
Total no. in group:
10
Remarks on result:
no indication of skin sensitisation
Reading:
2nd reading
Hours after challenge:
48
Group:
negative control
Dose level:
25%
No. with + reactions:
0
Total no. in group:
10
Remarks on result:
no indication of skin sensitisation
Reading:
1st reading
Hours after challenge:
24
Group:
test chemical
Dose level:
0%
No. with + reactions:
0
Total no. in group:
20
Remarks on result:
no indication of skin sensitisation
Reading:
2nd reading
Hours after challenge:
48
Group:
test chemical
Dose level:
0%
No. with + reactions:
0
Total no. in group:
20
Remarks on result:
no indication of skin sensitisation
Reading:
1st reading
Hours after challenge:
24
Group:
test chemical
Dose level:
25%
No. with + reactions:
0
Total no. in group:
20
Remarks on result:
no indication of skin sensitisation
Reading:
2nd reading
Hours after challenge:
48
Group:
test chemical
Dose level:
25%
No. with + reactions:
0
Total no. in group:
20
Remarks on result:
no indication of skin sensitisation

Any other information on results incl. tables

Viability/mortality: no death occurred during the study.

Clinical signs, local

Control group

Application area around the injection sites was found to show erythema and oedema from day 2 to 7; additionally around 2 of 3 injection sites necroses were observed from day 8 to 20; encrustation from day 19 to 21 and exfoliation from day 21 to 25 (termination of test). In addition staining was observed in the challenge application area from day 23 to 25.

Test group

Application area around one of the injection sites was found to show erythema and oedema from day 2 to 7. Application area around the other 2 injection sites showed oedema and staining from day 2 to 7. For the 3 injection sites necroses were observed from day 8 to 20; encrustation from day 19 to 21 and exfoliation from day 21 to 25. In addition epidermal induction and challenge application area showed staining from day 10 to 25 and 23 to 25 respectively.

On day 9 of test no observation could be performed because the animals were bandaged semi-occlusively.

Clinical signs, systemic

No systemic symptoms were observed in the animals.

Body weights

2 out of 10 control animals, 4 out of 20 test animals and both animals of the intradermal pretest lost weight during the acclimatization period. The body weight gain of the other animals was not affected during the entire study.

Applicant's summary and conclusion

Interpretation of results:
other: not classified according to the CLP Regulation (EC 1272/2008)
Conclusions:
Test substance was non sensitising in a Guinea pig maximisation test.
Executive summary:

Method

Guinea pig maximisation test was carried out according to OECD guideline 406. In the pretest, test substance was applied by intradermal route at concentrations of 1, 3 and 5 % and by epidermal route at concentrations of 5, 10, 15 and 25 %. Main study was conducted with 10 females in the control group and 20 females in the test group. Intradermal induction was done at a concentration of 5 % in physiological saline; epidermal induction and epidermal challenge were done with a concentration of 25 % in vaselinum album. Observations were performed 24 and 48 hours after challenge. Formaldehyde was applied as positive control.

Results

Local signs were reported at the injection site in both control and test group, in terms of erythema, oedema and necrosis. Epidermal application resulted in staining of the exposed area. No signs of systemic toxicity were noted. Based on the lack of positive responses after challenge, test substance resulted as non sensitising.

Positive control gave 80 % of positive response 24 and 48 hours after challenge.