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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
Study period:
8th January 2002 to 14th February 2002
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2002
Report Date:
2002

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 406 (Skin Sensitisation)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method B.6 (Skin Sensitisation)
Deviations:
no
Qualifier:
according to
Guideline:
EPA OPPTS 870.2600 (Skin Sensitisation)
Deviations:
no
GLP compliance:
yes
Type of study:
Buehler test
Justification for non-LLNA method:
The study was conducted prior to the adoption of the LLNA as a standard test guideline.

Test material

Reference
Name:
Unnamed
Type:
Constituent

In vivo test system

Test animals

Species:
guinea pig
Strain:
Hartley
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Females (if applicable) nulliparous and non-pregnant: Yes
- Microbiological status of animals, when known:
- Age at study initiation: Males were 6 weeks of age, females were 8 weeks of age
- Weight at study initiation: Males 350-431 g; Females 363-435 g
- Housing: Individually in suspended stainless steel cages.
- Diet: ad libitum
- Water: Municipal tap water treated by reverse osmosis, available ad libitum.
- Acclimation period: Minimum of 5 days.
- Indication of any skin lesions: Animals were subject to a deteailed pre-test before dosing. Only healthy animals were selected for the study.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 17-24 °C
- Humidity (%): 32-67 %
- Air changes (per hr): 10-15 changes per hour
- Photoperiod (hrs dark / hrs light): 12 hour light/dark cycle

Study design: in vivo (non-LLNA)

Induction
Route:
epicutaneous, occlusive
Vehicle:
unchanged (no vehicle)
Concentration / amount:
100 %
Day(s)/duration:
1, 7 and 21
Adequacy of induction:
highest technically applicable concentration used
Challengeopen allclose all
No.:
#1
Route:
epicutaneous, occlusive
Vehicle:
unchanged (no vehicle)
Concentration / amount:
100 %
Day(s)/duration:
28
Adequacy of challenge:
highest non-irritant concentration
No.:
#2
Route:
epicutaneous, occlusive
Vehicle:
propylene glycol
Concentration / amount:
100 and 50 %
Day(s)/duration:
35
Adequacy of challenge:
highest non-irritant concentration
No. of animals per dose:
10 males and 10 females in the definitive test
5 males and 5 females in the challenge control and rechallenge control
Details on study design:
RANGE FINDING TESTS:
A topical range-finding study was conducted in 2 males and 2 females.
The test material was administered at 100, 75, 50 and 25 % w/v in propylene glycol. On the day prior to dose administration, the guinea pigs were weighed and the hair removed from the right and left sides with a clipper, careful not to abrade the skin.
0.3 mL on the test material was applied in test chambers to the clipped surface and the trunk of the animal wrapped with elastic wrap secured with adhesive tape. After six hours the chambers were removed, and the sites wiped with gauze moistened in deionised water, and dried with gauze. The test sites were observed and graded for irritation at approximated 24 and 48 hours after test material application.


MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 3
- Exposure period: 6 hours
- Site: Left side
- Frequency of applications: Weekly
- Duration: 3 weeks
- Concentrations: 100 %

B. CHALLENGE EXPOSURE
- No. of exposures: 2
- Day(s) of challenge: 28 and 35
- Exposure period: 6 hours
- Site: Right side
- Concentrations: 100 % and 100 and 50 % for rechallenge
- Evaluation (hr after challenge): 24 and 48 hours after chamber removal.
Challenge controls:
The 1st challenge was performed with the neat substance. The rechallenge was performed on the right side at a different test site at 100 and 50 % concentrations.
Positive control substance(s):
yes
Remarks:
α-hexylcinnamaldehyde (5 %)

Results and discussion

Positive control results:
Following challenge with 2.5 w/v % of HCA in acetone, dermal scores of 1 were noted in 7/10 test animals at the 24-hour scoring interval. At 48 hours, dermal scores of 1 were noted in 4/10 animals. Dermal reactions in the remaining HCA test animals and HCA challenge control animals were limited to scores of 0 and ± (equivocal). Group mean dermal scores were noted to be higher in the test animals compared with the challenge control animals.
Following challenge with 1 % w/v HCA in acetone, dermal scores of 1 were note din 7/10 test animals at 24 hours. At 48 hours, scores of 1 were noted in 1/10 test animals. Dermal reactions in the remaining HCA test animals and HCA challenge control animals were limited to scores of 0 and ± (equivocal). Group mean dermal scores were noted to be higher in the test animals compared with the challenge control animals.

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:
12
Total no. in group:
20
Clinical observations:
Dermal scores of 1
Remarks on result:
positive indication of skin sensitisation
Key result
Reading:
2nd reading
Hours after challenge:
48
Group:
test group
Dose level:
100 %
No. with + reactions:
8
Total no. in group:
20
Clinical observations:
Dermal score of 1
Remarks on result:
positive indication of skin sensitisation
Key result
Reading:
rechallenge
Hours after challenge:
24
Group:
test group
Dose level:
100 %
No. with + reactions:
18
Total no. in group:
20
Clinical observations:
Dermal scores of 1
Remarks on result:
positive indication of skin sensitisation
Key result
Reading:
rechallenge
Hours after challenge:
48
Group:
test group
Dose level:
100 %
No. with + reactions:
16
Total no. in group:
20
Clinical observations:
dermal scores of 1
Remarks on result:
positive indication of skin sensitisation
Key result
Reading:
rechallenge
Hours after challenge:
24
Group:
test group
Dose level:
50 %
No. with + reactions:
12
Total no. in group:
20
Clinical observations:
Dermal scores of 1
Remarks on result:
positive indication of skin sensitisation
Key result
Reading:
rechallenge
Hours after challenge:
48
Group:
test group
Dose level:
50 %
No. with + reactions:
12
Total no. in group:
20
Clinical observations:
dermal scores of 1
Remarks on result:
positive indication of skin sensitisation

Any other information on results incl. tables

Table 1: Challenge Data

Group

Animal

Dermal Scores

24 Hours

Observation

48 Hours

Observation

Test Material Challenge

(100 %)

M1

±

±

M2

±

±

M3

±(IT)

±

M4

1

1

M5

±

±

M6

1

±

M7

1

1

M8

1

1

M9

±

±

M10

1

±

F1

1

1

F2

1

±

F3

1

1

F4

1

±

F5

1

1

F6

±

±

F7

1

1

F8

±

±

F9

±

±

F10

1

1

Mean

0.8

0.7

Challenge control

(100 %)

M11

0(IT)

0

M12

0(IT)

0

M13

0

0

M14

0

0

M15

0(IT)

0

F11

±

0

F12

0

0

F13

0

0

F14

±

0

F15

0

0

Mean

0.1

0

HCA Test

(2.5 %)

M16

±

±

M17

1

±

M18

1

±

M19

1

1

M20

±

±

F16

1

±

F17

1

1

F18

1

1

F19

±

±

F20

1

1

Mean

0.9

0.7

HCA Test

(1.0 %)

M16

±

0

M17

1

±

M18

1

±

M19

1

±

M20

±

0

F16

1

±

F17

1

±

F18

1

±

F19

±

±

F20

1

1

Mean

0.9

0.5

HCA Challenge Control

(2.5 %)

M21

0

0

M22

0

0

M23

0

0

M24

0

0

M25

0

0

F21

0

0

F22

0

0

F23

0

0

F24

0

0

F25

0

0

Mean

0

0

HCA Challenge Control

(1.0 %)

M21

0

0

M22

0

0

M23

0

0

M24

0

0

M25

0

0

F21

0

0

F22

0

0

F23

0

0

F24

0

0

F25

0

0

Mean

0

0

HCA Vehicle - Acetone

IT – Dermal irritation outside of test site

 

Table 2: Rechallenge data

Group

Animal

Dermal Scores

24 Hours Observation

48 Hours Observation

Test Material Rechallenge

(100 %)

M1

1

1

M2

1

±

M3

1

1

M4

1

1

M5

1

1

M6

1

1

M7

1

1

M8

1

1

M9

1

1

M10

1

1

F1

1

1

F2

±

±

F3

1

1

F4

1

1

F5

1

1

F6

1

1

F7

1

1

F8

1

±

F9

±

±

F10

1

1

Mean

1

0.9

Test Material Rechallenge

(50 %)

M1

1

1

M2

±

0

M3

±

±

M4

1

1

M5

1

1

M6

1

1

M7

1

1

M8

±

±

M9

1

1

M10

1

1

F1

±

±

F2

±

±

F3

1

1

F4

1

1

F5

1

1

F6

1

1

F7

±

0

F8

±

0

F9

±

±

F10

1

1

Mean

0.8

0.7

Challenge control

(100 %)

M26

0

0

M27

0

0

M28

0

0

M29

0

0

M30

0

0

F26

0

0

F27

0

0

F28

0

0

F29

0

0

F30

0

0

Mean

0

0

Challenge control

(50 %)

M26

0

0

M27

0

0

M28

0

0

M29

0

0

M30

0

0

F26

0

0

F27

0

0

F28

0

0

F29

0

0

F30

0

0

Mean

0

0

Vehicle - propylene glycol

 

Applicant's summary and conclusion

Interpretation of results:
Category 1B (indication of skin sensitising potential) based on GHS criteria
Conclusions:
Under the conditions of the test, the test material was determined to be a contact sensitiser at the concentrations tested. The results of the positive control demonstrated that a valid test was performed.
Executive summary:

The dermal sensitisation potential of the test material was investigated in the Buehler test conducted on male and female Hartley guinea pigs, in accordance with OECD 406, EU Method B.6 and EPA OPPTS 870.2600.

Ten male and ten female guinea pigs were topically treated with the neat test material once per week for three consecutive weeks. The challenge test was performed after a rest period of two weeks. The challenge test was administered neat to the twenty animals in the test group and ten (five male and five female) naïve challenge control animals. Challenge responses were recorded at 24 and 48 hours. Following a seven day rest period, a rechallenge was performed with the twenty test animals and ten naïve test rechallenge control animals. The rechallenge animals were topically treated with the test material at 100 % and 50 % in propylene glycol.

A positive control group treated withα-Hexylcinnamaldehyde (HCA) was included to demonstrate the validity of the study.

Under the conditions of the test, the test material was determined to be a contact sensitiser at the concentrations tested. The results of the positive control demonstrated that a valid test was performed.