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Administrative data

Endpoint:
skin sensitisation: in vivo (non-LLNA)
Type of information:
experimental study
Adequacy of study:
supporting study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: The procedures used in the test are in compliance with the OECD Guideline for Testing of Chemicals No. 406.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1996
Report date:
1996

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 406 (Skin Sensitisation)
Deviations:
yes
Remarks:
temperature fell below the specified range by 1 °C on one occasion
GLP compliance:
yes
Type of study:
guinea pig maximisation test

Test material

Constituent 1
Reference substance name:
reaction mass of Lycopyl salt isomers
IUPAC Name:
reaction mass of Lycopyl salt isomers
Details on test material:
- Name of test material (as cited in study report): (2E,4E,6E)-(3,7,11-Trimethyl-dodeca-2,4,6,10-tetraenyl)-triphenyl-phosphonium acetate
- Physical state: clear yellow liquid
- Lot/batch No.: P19-39.5
- Storage condition of test material: In refrigerator at 2-8 °C, protected from light, covered with Nitrogen

In vivo test system

Test animals

Species:
guinea pig
Strain:
Dunkin-Hartley
Sex:
female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: D. Hall, Darley Oaks, Burton-on-Trent, England
- Age at study initiation:
- Weight at study initiation: 300-350 g
- Housing: up to five in stainless steel cages
- Diet (e.g. ad libitum): diet pellets SQC FD1 guinea pig diet with added vitamin C (Special Diet Services, Witham, England)
- Water (e.g. ad libitum): mains drinking water
- Acclimation period: pre-test for five days, seconder intradermal range finding test for 13 days, main test for 26 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18-22
- Humidity (%): 52-69
- Air changes (per hr):
- Photoperiod (hrs dark / hrs light): 12/12


IN-LIFE DATES: From: To:

Study design: in vivo (non-LLNA)

Induction
Route:
intradermal and epicutaneous
Vehicle:
water
Challenge
Route:
epicutaneous, occlusive
Vehicle:
water
Details on study design:
RANGE FINDING TESTS:
A ranging study was performed in one animal for intradermal injection. 7 days previously, the animal had been treated with 4 intradermal injections of a 1:1 mixture of Freund's Complete Adjuvant (FCA) and water.
0.1 mL aliquots of 50 %, 25 %, 10 %, 5 %, 1 % and 0.5 % (v/v) concentrations of the test article in water were injected dermally into the flanks of the guinea pig. The animal was examined on the day of dosing and then daily thereafter for a further 2 days. The resulting intradermal response was unacceptably severe. Test article concentrations of 0.1 %, 0.05 % and 0.01 % (v/v) were administered to an additional FCA/water treated animal and the injection sites examined daily for 6 days. All concentrations used in this second test produced severe responses. A concentration of 0.005 % (v/v) was anticipated to not provoke an unacceptable skin response.
4 animals were pretreated with 1:1 FCA/water as described above. The concentrations used in the topical range finding study were undiluted test article and 50 %, 25 %, 12.5 % (v/v) concentrations of the test article in water. 4 patches each saturated with a different concentration of the test article were placed onto the skin (previously clipped free of fur) on each flank. The site was occluded and the patches were held in place for 24 hours. Twenty four and 48 hours after removing the patches, the animals were examined under standard light and any reaction at the treated site was assessed. The test showed that undiluted test article was minimally irritant and suitable for the topical induction stage. A 50 % (v/v) concentration of the test article in water was the maximum non irritant concentration and was selected for use for the

MAIN STUDY
A. INDUCTION EXPOSURE: intradermal
- No. of exposures: three pairs of intradermal injections
- Exposure period:
- Test groups: 20 animals, randomly selected
- Control group: 10 animals, randomly selected
- Site: dorsal area between the shoulders
- Concentrations: Test group: 50 % v/v FCA emulsified in water; 0.005 % v/v test article in water; 0.005 % v/v concentration of the test article in a 1:1 emulsion of FCA and water; Control group: 50 % v/v FCA emulsified in water; water; water mixed with a 1:1 emulsion of FCA and water to give a vehicle concentration of 50 % v/v

A. INDUCTION EXPOSURE: epicutaneous
- No. of exposures: one patch over the injection sites (4 x 2 cm), skin treated with 0.5 mL of 10 % w/v sodium lauryl sulphate in light liquid paraffin
- Exposure period: seven days after intradermal induction
- Test groups: 20 animals
- Control group: 10 animals
- Site: dorsal area between the shoulders
- Frequency of applications: once
- Duration: occlusive for 48 hours
- Concentrations: undiluted

B. CHALLENGE EXPOSURE
- No. of exposures: one patch on each flank of testing animals
- Day(s) of challenge: fourteen days after topical induction
- Exposure period:
- Test groups: 20 animals
- Control group: 10 animals
- Site: right and left flanks
- Concentrations: 50 % v/v of test article in water
- Evaluation (hr after challenge): twenty four and 48 hours after removal of patches


OTHER: Mercaptobenzothiazole was used as a positive control as this is known to be a sensitiser. The material was administered as a 10 % w/v concentration in light liquid paraffin for the intradermal injection phase. Seven days after administration of the intradermal injections, MBT was administered topically to animals in the test group at a concentration of 10 % w/v in acetone whilst animals in the control group were treated with acetone alone. Fourteen days after this topical application, a 10 % w/v concentration of MBT in acetone was applied to the left flank of all test and control animals whilst acetone alone was applied to the right flank. Both sites were then occluded for 24 hours. Skin sites were examined and the skin responses were scored 24 and 48 hours ater the end of the occlusion period.
Positive control substance(s):
yes
Remarks:
Mercaptobenzothiazole (MBT)

Results and discussion

Positive control results:
Four of the 10 test animals exhibited positive responses to challenge with 10 % MBT at the 24 and the 48 hours observations, resulting in a response incidence of 40 %. None of the test animals responded to challenge with the vehicle at any of the observations.
None of the control animals responded to challenge with either 10 % MBT or the vehicle at any of the observations.
These results confirm that MBT is a moderate sensitiser under the conditions of the study and the test system is therefore considered to be valid.

In vivo (non-LLNA)

Resultsopen allclose all
Reading:
1st reading
Hours after challenge:
24
Group:
test chemical
Dose level:
50 % v/v test article in water
No. with + reactions:
9
Total no. in group:
20
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 50 % v/v test article in water. No with. + reactions: 9.0. Total no. in groups: 20.0.
Reading:
2nd reading
Hours after challenge:
48
Group:
test chemical
Dose level:
50 % v/v test article in water
No. with + reactions:
12
Total no. in group:
20
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 50 % v/v test article in water. No with. + reactions: 12.0. Total no. in groups: 20.0.
Reading:
1st reading
Hours after challenge:
24
Group:
negative control
Dose level:
50 % v/v test article in water
No. with + reactions:
0
Total no. in group:
10
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. Dose level: 50 % v/v test article in water. No with. + reactions: 0.0. Total no. in groups: 10.0.
Reading:
2nd reading
Hours after challenge:
48
Group:
negative control
Dose level:
50 % v/v test article in water
No. with + reactions:
0
Total no. in group:
10
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: negative control. Dose level: 50 % v/v test article in water. No with. + reactions: 0.0. Total no. in groups: 10.0.
Reading:
1st reading
Hours after challenge:
24
Group:
positive control
Dose level:
10 % MBT
No. with + reactions:
4
Total no. in group:
10
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: positive control. Dose level: 10 % MBT. No with. + reactions: 4.0. Total no. in groups: 10.0.
Reading:
2nd reading
Hours after challenge:
48
Group:
positive control
Dose level:
10 % MBT
No. with + reactions:
4
Total no. in group:
10
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: positive control. Dose level: 10 % MBT. No with. + reactions: 4.0. Total no. in groups: 10.0.

Any other information on results incl. tables

Table 1: Individual skin responses during the challenge phase

Group

Cage no.

Animal no.

50 % test article

Water

Test

11

1

0

1

0

0

2

1

0

0

0

3

0

0

0

0

4

0

0

0

0

5

1

1

0

0

12

1

1

1

0

0

2

1

1

0

0

3

0

1

0

0

4

1

1

0

0

5

1

1

0

0

13

1

0

1

0

0

2

0

0

0

0

3

1

1

0

0

4

0

0

0

0

5

0

0

0

0

14

1

1

2

0

0

2

0

0

0

0

3

1

1

0

0

4

0

1

0

0

5

0

0

0

0

Control

15

1

0

0

0

0

2

0

0

0

0

3

0

0

0

0

4

0

0

0

0

5

0

0

0

0

16

1

0

0

0

0

2

0

0

0

0

3

0

0

0

0

4

0

0

0

0

5

0

0

0

0

Applicant's summary and conclusion

Interpretation of results:
sensitising
Remarks:
Migrated information
Conclusions:
Based upon the results of the experiment, it is concluded that Ro 44-9567/002 exhibits a moderate to strong sensitisation potential on the guinea pig under the conditions of the study.
Executive summary:

In order to assess the skin sensitisation potential of Ro 44 -9567/002, the Maximisation Test in accordance with OECD Guideline No. 406 was carried out in 30 (20 test and 10 control) female albino guinea pigs.

The intradermal induction of sensitisation was carried out with 0.005 % v/v solution of the test article in water or in emulsion with Freund's Complete Adjuvent. The epicuataneous induction of sensitisation was conducted with undiluted test article under occlusion. Two weeks after the epidermal induction, the challenge was completed by epicutaneous application of the test article in the highest non irritating concentration, i.e., 50 % v/v in water (as determined in the range finding phase of the study) under occlusive dressing.

13 of the test animals exhibited positive skin reactions after challenge with 50 % v/v test article in water (Table 1), giving a response incidence of 65 %. None of the animals in the control group responded positively to challenge with 50 % v/v test article in water.

Based upon the results of the experiment, it is concluded that Ro 44-9567/002 exhibits a moderate to strong sensitisation potential on the guinea pig under the conditions of the study.