Registration Dossier

Administrative data

Endpoint:
skin sensitisation: in vivo (non-LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Study period:
08 April 2004 - 14 September 2004
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2004
Report Date:
2004

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 406 (Skin Sensitisation)
Version / remarks:
1992
Deviations:
no
Qualifier:
according to
Guideline:
EU Method B.6 (Skin Sensitisation)
Version / remarks:
1996
Deviations:
no
GLP compliance:
yes (incl. certificate)
Type of study:
guinea pig maximisation test
Justification for non-LLNA method:
The study was performed before the guideline for the LLNA entered into force.

Test material

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

In vivo test system

Test animals

Species:
guinea pig
Strain:
Dunkin-Hartley
Sex:
male
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River Deutschland GmbH, Stolzenseeweg 32 - 36 D-88353 Kißlegg, Germany
- Age at study initiation: 27 days
- Weight at study initiation: 274 -302 g (excluding positive control group), positive control group: 247 - 314 g
- Housing: in pairs in MAKROLON cages (type IV)
- Diet: ssniff® Ms-H V2233 (ssniff Spezialdiaten GmbH, D-59494 Soest, Germany), ad libitum
- Water: tap water, ad libitum

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 ± 3
- Humidity (%): 55 ± 15
- Photoperiod (hrs dark / hrs light): 12 / 12

Study design: in vivo (non-LLNA)

Inductionopen allclose all
Route:
intradermal
Vehicle:
vegetable oil
Remarks:
sesame oil
Concentration / amount:
50 % / 0.1 mL
Day(s)/duration:
day 1 / 2 injections
Adequacy of induction:
highest concentration used causing mild-to-moderate skin irritation and well-tolerated systemically
Route:
epicutaneous, occlusive
Vehicle:
unchanged (no vehicle)
Concentration / amount:
100 % / 2 mL
Day(s)/duration:
day 8 / 48 hours
Adequacy of induction:
non-irritant substance, but skin pre-treated with 10% SDS
Challenge
No.:
#1
Route:
epicutaneous, occlusive
Vehicle:
unchanged (no vehicle)
Concentration / amount:
100 % / 2 mL
Day(s)/duration:
day 22 / 24 hours
No. of animals per dose:
test item: 10
vehicle control: 5
positive control: 20 (not tested concurrently with this study, historical background group from a study performed April/May 2004)
Details on study design:
RANGE FINDING TESTS:
A range finding test was performed with eight animals. Six animals were used for the topical administration and two animals for the intracutaneous administration. Six concentrations of the test item were tested by intracutaneous injection: 0.01, 0.1, 1, 10 or 50% suspensions in sesame oil and the undiluted test item. No skin reactions were observed at concentrations up to the concentration of 0.1 % test item in sesame oil. Concentrations of 1 % and 10% revealed a discrete or patchy erythema 24 hours after administration. A concentration of 50% revealed a moderate and confluent erythema 24 hours, a discrete or patchy erythema 48 and 72 hours after administration. Administration of the undiluted test item revealed a moderate and confluent erythema 24, 48 and 72 hours after administration. Furthermore, six concentrations of the test item were tested by topical application: 1, 5, 10, 25 and 50% suspensions in sesame oil and the undiluted test item. No skin reactions were observed, neither to the shaved nor to the depilated skin. Hence, it was decided to use a 50% suspension in sesame oil for the 1st (intracutaneous) induction stage and the undiluted test item for the 2nd (topical) induction stage and for the challenge.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: intradermal exposure: 2 injections with 0.1 mL of Freund's Adjuvant (diluted 1 : 1 with 0.9% NaCI), 2 injections with 0.1 mL of the test item (50 %), 2 injections with 0.1 mL of a 1:1 mixture of the test item (50 %) and Freund's Adjuvant; epicutaneous exposure: one application
- Exposure period: 48 hours (epicutaneous exposure)
- Test groups: 10 animals
- Control group: vehicle control group: 5 animals, positive control group: 20 animals
- Site: shoulder region
- Frequency of applications:
- Duration: 48 hours (epicutaneous exposure)
- Concentrations: 50% (intradermal exposure), 100% (epicutaneous exposure)

B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Day of challenge: 22
- Exposure period: 24 hours
- Test groups: 10 animals
- Control group: vehicle control group: 5 animals, positive control group: 20 animals
- Site: shoulder region
- Concentrations: 100%
- Evaluation (hr after challenge): 24, 48 and 72
Positive control substance(s):
yes
Remarks:
Benzocaine

Results and discussion

Positive control results:
Animals of this strain treated with benzocaine in 40% ethanolic 0.9% NaCI solution exhibited a sensitising reaction in all animals in form of a discrete or patchy erythema (grade 1) or moderate and confluent erythema (grade 2).

In vivo (non-LLNA)

Resultsopen allclose all
Key result
Reading:
1st reading
Hours after challenge:
24
Group:
test group
Dose level:
100%
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
no clinical signs
Remarks on result:
no indication of skin sensitisation
Key result
Reading:
2nd reading
Hours after challenge:
48
Group:
test group
Dose level:
100%
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
no clinical signs
Remarks on result:
no indication of skin sensitisation
Key result
Reading:
other: 3rd reading
Hours after challenge:
72
Group:
test group
Dose level:
100%
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
no clinical signs
Remarks on result:
no indication of skin sensitisation
Reading:
1st reading
Hours after challenge:
24
Group:
negative control
No. with + reactions:
0
Total no. in group:
5
Clinical observations:
no clinical signs
Remarks on result:
no indication of skin sensitisation
Reading:
2nd reading
Hours after challenge:
48
Group:
negative control
No. with + reactions:
0
Total no. in group:
5
Clinical observations:
no clinical signs
Remarks on result:
no indication of skin sensitisation
Reading:
other: 3rd reading
Hours after challenge:
72
Group:
negative control
No. with + reactions:
0
Total no. in group:
5
Clinical observations:
no clinical signs
Remarks on result:
no indication of skin sensitisation
Reading:
1st reading
Hours after challenge:
24
Group:
positive control
Dose level:
40% benzocaine
No. with + reactions:
20
Total no. in group:
20
Remarks on result:
positive indication of skin sensitisation
Reading:
2nd reading
Hours after challenge:
48
Group:
positive control
Dose level:
40% benzocaine
No. with + reactions:
20
Total no. in group:
20
Remarks on result:
positive indication of skin sensitisation
Reading:
other: 3rd reading
Hours after challenge:
72
Group:
positive control
Dose level:
40% benzocaine
No. with + reactions:
20
Total no. in group:
20
Remarks on result:
positive indication of skin sensitisation

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
Conclusions:
Under the present test conditions, the test item revealed no sensitising properties in guinea pigs.
Executive summary:

The purpose of this study according to OECD guideline 406 was to determine the potential of the test item to provoke skin sensitisation reactions in guinea pigs. A 50% suspension of the test item in sesame oil chosen for the 1st (intracutaneous) induction stage revealed a discrete or patchy erythema in all 10 animals 25 and 48 hours after administration. 2 mL of the undiluted test item chosen for stage 2 (topical) induction was not irritating to the non-depilated skin in the preliminary experiment. Hence, in the main study the skin was coated with sodium laurylsulfate on the day before stage 2 induction (day 7 after the first induction) in order to induce a local irritation. The challenge with 2 mL of the undiluted test item/animal revealed no skin irritation in any animal and, thus, the test item had no sensitising properties. The vehicle control revealed no skin reactions per se, either. Animals of this strain treated with benzocaine in 40% ethanolic 0.9% NaCI solution exhibited a sensitising reaction in all animals in form of a discrete or patchy erythema (grade 1) or moderate and confluent erythema (grade 2). The body weight gain of the animals treated with the test item was within the range of the vehicle control during the experiment. Behaviour remained unchanged. Under the present test conditions, the test item revealed no sensitising properties in guinea pigs.