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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:
weight of evidence
Study period:
25 July - 25 Aug 1989
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study with acceptable restrictions
Remarks:
No reliability check and no irritation scores for the induction phase were reported.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1989
Report Date:
1989

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 406 (Skin Sensitisation)
Version / remarks:
1981
Deviations:
yes
Remarks:
no reliability check and no irritation scores for the induction phase were reported
GLP compliance:
yes
Type of study:
guinea pig maximisation test
Justification for non-LLNA method:
The test was done before LLNA as first-choice method for in-vivo testing was set into force.

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
- Age at study initiation: 6-7 weeks old
- Weight at study initiation: 275-350 g
- Housing: 2-3 animals per cage in opaque PPL cages (Type IV), pinewood sawdust was used as bedding material
- Diet: Altromin 3113 (Chr. Petersen Ltd, Jorløse, Jerslev, Denmark), ad libitum
- Water: Vitamin C enriched tap water, ad libitum
- Acclimation period: no data

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21 ± 2
- Humidity (%): 55 ± 15
- Air changes (per hr): 6
- Photoperiod (hrs dark / hrs light): 12/12

Study design: in vivo (non-LLNA)

Induction
Route:
intradermal and epicutaneous
Vehicle:
other: intradermal induction: paraffin oil; dermal induction: 70% ethanol
Concentration / amount:
intradermal: 1%, epicutaneous: 25%
Day(s)/duration:
intradermal induction: on Day 0; dermal induction: on Day 7
Adequacy of induction:
non-irritant substance, but skin pre-treated with 10% SDS
Challengeopen allclose all
No.:
#1
Route:
epicutaneous, semiocclusive
Vehicle:
other: 70% ethanol
Concentration / amount:
2%
Day(s)/duration:
3 weeks after intradermal induction; exposure period: 24 h
Adequacy of challenge:
highest non-irritant concentration
No.:
#2
Route:
epicutaneous, semiocclusive
Vehicle:
other: 70% ethanol
Concentration / amount:
0.2%
Day(s)/duration:
1 week after challenge
No. of animals per dose:
20 (controls), 20 (test group)
Details on study design:
RANGE FINDING TESTS:
A range finding study was performed to determine the appropriate dose level of the test substance following intradermal and topical administrations. The intradermal irritancy of the test substance was investigated in order to find a slight to moderate irritant test substance concentration for the intradermal induction using intradermal injections as in the main study. For the intradermal administration test item concentrations of 0.63, 1.25, 2.5 or 5% were injected intradermal ten times in two animals each. Slight erythema was observed at 0.63%, moderate erythema at 1.25% and moderate to severe erythema with necrosis at 2.5 and 5% test substance.
The topical irritancy of the test substance was investigated in order to find a slight to moderate irritant test substance concentration for the dermal induction using closed patch tests as in the main study. For the topical administration test item concentrations of 50 and 100% were applied two times each to the skin of two animals. Moderate to severe erythema was observed at 50 and 100% test substance.
The topical irritancy of the test substance was investigated in order to find the highest non-irritant test substance concentration for the challenge application. For the topical administration test item concentrations of 0.25, 0.5, 1.0 and 2.0% were applied each with 3 patches to the skin of 3 animals. Additionally, test substance concentrations of 3.13, 6.25, 12.5 and 25% were applied each with 3 patches to the skin of further 3 animals. No skin reactions were observed up to and including 1.0% test substance concentration. At 2.0% test substance concentration, no skin reactions were observed in 2/3 animals and very slight erythema was observed in 1 animal. Slight to moderate erythema was noted at 3.13% test substance concentration. At 6.25 and 12.5% test substance concentration, moderate erythema was noted. Moderate to severe erythema was observed at 25% test substance concentration.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 2 (intradermal and epicutaneous, respectively)
- Exposure period: single injection (intradermal) and 48 h (epicutaneous)
- Test groups:
Intradermal (3 pairs of injections):
Injection 1: a 1:1 mixture FCA/water
Injection 2: test substance in paraffin oil
Injection 3: equal amounts of 2% test substance and FCA
Epicutaneous: 25% test substance
- Control group:
Injection 1: a 1:1 mixture FCA/water
Injection 2: paraffin oil
Injection 3: equal amounts of paraffin oil and FCA
Epicutaneous: 70% ethanol
- Site: scapular region (intradermal + epicutaneous)
- Frequency of applications: every 7 days
- Duration: Days 0-7
- Concentrations: intradermal 1%, epicutaneous 25%

B. CHALLENGE EXPOSURE
- No. of exposures: 2 (challenge and rechallenge)
- Day of challenge: 21 (challenge) and 28 (rechallenge)
- Exposure period: 24 h
- Test groups: 2% test substance and 70% ethanol (challenge); 0.2% test substance (rechallenge)
- Control group: 2% test substance and 70% ethanol (challenge); 0.2% test substance (rechallenge)
- Site: right flank (test substance) and left flank (70% ethanol) (challenge); right flank (rechallenge)
- Concentrations: 2% (challenge) and 0.2% (rechallenge)
- Evaluation: 24, 48 and 72 h after patch removal
Challenge controls:
The control group is actually a challenge control.
Positive control substance(s):
not specified

Results and discussion

In vivo (non-LLNA)

Resultsopen allclose all
Reading:
1st reading
Hours after challenge:
24
Group:
negative control
Dose level:
Induction intradermal: 0%; challenge: 2%
No. with + reactions:
0
Total no. in group:
20
Key result
Reading:
1st reading
Hours after challenge:
24
Group:
test group
Dose level:
Induction intradermal: 1%; challenge: 2%
No. with + reactions:
16
Total no. in group:
20
Reading:
2nd reading
Hours after challenge:
48
Group:
negative control
Dose level:
Induction intradermal: 0%; challenge: 2%
No. with + reactions:
0
Total no. in group:
20
Key result
Reading:
2nd reading
Hours after challenge:
48
Group:
test group
Dose level:
Induction intradermal: 1%; challenge: 2%
No. with + reactions:
15
Total no. in group:
20
Reading:
other: 3rd reading
Hours after challenge:
72
Group:
negative control
Dose level:
Induction intradermal: 0%; challenge: 2%
No. with + reactions:
0
Total no. in group:
20
Key result
Reading:
other: 3rd reading
Hours after challenge:
72
Group:
test group
Dose level:
Induction intradermal: 1%; challenge: 2%
No. with + reactions:
15
Total no. in group:
20
Reading:
rechallenge
Hours after challenge:
24
Group:
negative control
Dose level:
Induction intradermal: 0%; challenge: 2%; rechallenge: 0.2%
No. with + reactions:
0
Total no. in group:
20
Reading:
rechallenge
Hours after challenge:
24
Group:
test group
Dose level:
Induction intradermal: 1%; challenge: 2%; rechallenge: 0.2%
No. with + reactions:
0
Total no. in group:
20

Any other information on results incl. tables

Induction

Intradermal injections of Freund's complete adjuvant mixed with test substance or vehicle elicited irritation. A slight to moderate skin reaction was observed following the intradermal injections of the test substance. Moderate to severe skin reactions were observed at the backs of the test animals after the dermal induction.

 

Rechallenge

No positive skin reactions were registered indicating a possible dose-response relationship between challenge concentration and sensitization rate.

 

Body weight

The animals made normal body weight changes over the duration of the study and exhibited normal appearance and behaviour.

Applicant's summary and conclusion

Interpretation of results:
other: Skin Sens. 1A
Remarks:
according to Regulation (EC) No 1272/2008
Conclusions:
Under the conditions of the guinea pig maximisation test the test substance revealed sensitising properties.
Executive summary:

A maximisation test in guinea pigs was performed according to OECD 406 and GLP in 1989.

The intradermal induction was 1 % in paraffin oil, topical induction was 25 % in EtOH 70 % and the challenge was performed with 2 % in EtOH 70 %. The rechallenge was 0.2 % in 70 % EtOH.

Challenge: 18/20 animals showed skin reactions at 24 hours, thereof 16 with grade >=2 and 15/20 had grade >=2 after 48 and 72 hours. In the control group 5/20 had grade 1 reactions after 24 hours, decreasing to 2 animals after 48 hours and 1 animal after 72 hours.

Rechallenge: In the test group and the control group only grade 1 reactions occurred.

According to this test the substance is a skin sensitiser (CLP Cat 1A).