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Toxicological information

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
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Study was conducted similar to the OECD guidance 406 and the EU method B.6
Cross-referenceopen allclose all
Reason / purpose:
reference to same study
Reason / purpose:
reference to other study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1975
Report Date:
1975

Materials and methods

Test guidelineopen allclose all
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 406 (Skin Sensitisation)
Deviations:
yes
Remarks:
; observations made only at single time point (i.e. 48 h after challenge) and not at 72 h
Qualifier:
equivalent or similar to
Guideline:
EU Method B.6 (Skin Sensitisation)
Deviations:
yes
Remarks:
; observations made only at single time point (i.e. 48 h after challenge) and not at 72 h
GLP compliance:
not specified
Type of study:
guinea pig maximisation test
Justification for non-LLNA method:
Study was conducted before LLNA method implementation

Test material

Reference
Name:
Unnamed
Type:
Constituent

In vivo test system

Test animals

Species:
guinea pig
Strain:
Dunkin-Hartley
Sex:
female
Details on test animals and environmental conditions:
TEST ANIMALS
- Weight at study initiation: 300-400 g
- Housing: groups of 5 animals in cage
- Diet: ad libitum (standard diet for guinea pigs)
- Water: ad libitum (a supplement of ascorbic acid was dissolved in the drinking water)

Study design: in vivo (non-LLNA)

Inductionopen allclose all
Route:
intradermal and epicutaneous
Vehicle:
water
Concentration / amount:
Injection: 1.0%
Topical: 5.0%
Challenge: 0.25%
Challengeopen allclose all
Route:
epicutaneous, occlusive
Vehicle:
water
Concentration / amount:
Injection: 1.0%
Topical: 5.0%
Challenge: 0.25%
No. of animals per dose:
10
Details on study design:
RANGE FINDING TESTS: The maximum sub-irritant concentration to be used in the main test was determined in preliminary experiments in which a series of concentrations of the test agents were applied.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: Intradermal injections - three; topical application - single
- Exposure period: 48 h (topical application)
- Test group: Intradermal injections - Two rows of 3 intradermal injections were given on each side of the midline.
i) 0.1 mL Freunds adjuvent alone
ii) 0.1 mL test agent alone
iii) 0.1 mL test agent emulsified with Freunds adjuvent
Topical application - 6 d later the injection sites were shaved and treated with 10% sodium lauryl sulphate. The sites were left unbandaged for 24 h and after that a patch of test substance was applied occlusively for 48 h.
- Control groups: During the induction period the control animals were treated similarly to the test animals with the exception that the test compound was replaced with positive (p-phenylenediamine) and negative control (SLS), respectively.
- Concentrations: the test group: 1% (injection) and 5% (topical); the positive control group: 2.0% (injection and topical); the negative control group: 1% (injection) and 5% (topical)
- Frequency of applications: Topical application was made 1 wk after intradermal injections

B. CHALLENGE EXPOSURE
- No. of exposures: Single
- Day(s) of challenge: 1 d
- Exposure period: 24 h
- Test groups: The animals were challenged with test material topically 2 wks after the induction period. The challenge patch were removed after 24 h
- Control group: The control animals were treated similarly to the test animals with the exception that the test compound was replaced with positive (p-phenylenediamine) and negative control (SLS), respectively.
- Site: Flank
- Concentrations: the test group: 0.25%; the positive control group: 2.0%; the negative control group 0.5%
- Evaluation (h after start of challenge): 48 h
Challenge controls:
No data
Positive control substance(s):
yes
Remarks:
(2% p-phenylenediamine)

Results and discussion

Positive control results:
The group treated with p-phenylenediamine showed a positive reaction of 80%, which classifies it as a strong sensitiser.

In vivo (non-LLNA)

Resultsopen allclose all
Reading:
1st reading
Hours after challenge:
48
Group:
negative control
Dose level:
0.5%
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
-
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 48.0. Group: negative control. Dose level: 0.5%. No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: -.
Reading:
1st reading
Hours after challenge:
48
Group:
test group
Dose level:
0.25%
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
-
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 48.0. Group: test group. Dose level: 0.25%. No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: -.
Reading:
1st reading
Hours after challenge:
48
Group:
positive control
Dose level:
2%
No. with + reactions:
8
Total no. in group:
10
Clinical observations:
-
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 48.0. Group: positive control. Dose level: 2%. No with. + reactions: 8.0. Total no. in groups: 10.0. Clinical observations: -.

Any other information on results incl. tables

No reactions were observed on the guinea pigs treated with the test substance.

Applicant's summary and conclusion

Conclusions:
The substance did not induce skin sensitisation in guinea pig maximisation test.
Executive summary:

A study was conducted to evaluate if the substance induces sensitisation in guinea pigs. The test was conducted equivalent or similar to OECD Guideline 406 and the EU Method B.6. Ten female Dunkin-Hartley guinea pigs per group were used in the test. The procedure consisted of two parts: induction and challenge exposures. Doses were determined on the basis of preliminary investigations. The following test concentrations and protocol were used:

(i) Induction injection: 1.0% [two rows of 3 intradermal injections (Freunds adjuvent alone; test agent alone; test agent emulsified with Freunds adjuvant) were given on each side of the midline]

(ii) Induction topical application: 5.0% (a patch was applied occlusively for 48 h after 1 wk of injections)

(iii) Challenge: 0.25% (a patch was applied occlusively for 24 h after 2 weeks of induction)

The degree of response was determined 24 h after removal of the challenge patch. A positive control group was treated with p-phenylenediamine and a negative control group was treated with sodium lauryl sulphate. The positive control group showed a positive reaction of 80%, which classifies it as a strong sensitiser. None of the negative control or test animals showed sensitization reactions. In conclusion, the test substance did not induce skin sensitisation in guinea pig maximisation test (Cuthbert JA, 1975).