(E)-5[(4-chlorophenyl)methylene]-2,2-dimethylcyclopentanone

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1992

Reliability:

1 (reliable without restriction)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1992

Report date:

1992

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

GLP compliance:

yes

Type of study:

guinea pig maximisation test

Test material

Test material information

Constituent 1

Reference substance name:

(E)-5[(4-chlorophenyl)methylene]-2,2-dimethylcyclopentanone

EC Number:

410-440-9

EC Name:

(E)-5[(4-chlorophenyl)methylene]-2,2-dimethylcyclopentanone

Cas Number:

164058-20-2

Molecular formula:

C14 H15 Cl O

IUPAC Name:

(5E)-5-[(4-chlorophenyl)methylidene]-2,2-dimethylcyclopentan-1-one

Details on test material:

- Name of test material (as cited in study report): RPA 405217
- Substance type: white powder
- Expiration date of the lot/batch: Mai 1994
- Solubility: 7 mg/L at 20 °C
- Lot/batch No.: DA 696
- Storage condition of test material: room temperature

In vivo test system

Test animals

Species:

guinea pig

Strain:

Dunkin-Hartley

Sex:

male/female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Lebeau breeding centre, 78950 Gambais, France
- Age at study initiation:
- Weight at study initiation: 379 ± 23 g for males, 364 ± 32 g for females,
- Housing: During the acclimatization period and throughout the study, the animals were housed individually in sterilizable polycarbonate cages (48 x 27 x 20 cm) equipped with a polypropylene water bottle
- Diet: During the study, the animals were fed ad libitum with a certified pelleted diet (Guinea-pigs sustenance ref. 106 - U.A.R. 91360 Villemoissonsur-Orge , France
- Water : Water filtered by a 0.22 micron filter membrane (Société Millipore, 78140 Vélizy, France) and contained in water bottles was given ad ibitum during the study.
- Acclimation period: minimum 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 ± 3
- Humidity: 50 ± 20 % relative humidity
- Air: the air was non-recycled and filtered by absolute filters.
- Photoperiod (hrs dark / hrs light): 12

Study design: in vivo (non-LLNA)

Induction

Induction 1

Route:

intradermal and epicutaneous

Vehicle:

paraffin oil

Induction 2

Concentration / amount:

- 5 % by intradermal route
- unchanged by cutaneous route and challenge application

Challenge

Challenge 1

Route:

epicutaneous, occlusive

Vehicle:

paraffin oil

Challenge 2

Concentration / amount:

- 5 % by intradermal route
- unchanged by cutaneous route and challenge application

No. of animals per dose:

30 guinea-pigs (15 males and 15 females) were allocated to 2 groups: a control group (5 males and 5 females) and a treated group (10 males und 10 females).

Details on study design:

RANGE FINDING TESTS:

A preliminary test enabled the definition of the dose of the test substance to be administered in the main study. The potential sensitization of the animals by intradermal route was performed by administration of the test substance, at a concentration of 5 % in the vehicle, which was the maximum administrable dose using a syringe und which was an irritant dose.

The Potential sensitization of the animals by cutaneous route und challenge application were performed with the test substance as supplied, which is the maximum non-irritant dose when covered using an occlusive dressing for 24 hours.


MAIN STUDY

The sensitization potential of the test substance was evaluated after a 10-day induction period during which the animals were treated with the vehicle (control group) or the test substance (treated group).

On day 1, in presence of Freund's adjuvant, 0.1 ml of the test substance was administered by intradermal route at a concentration of 5 % in
paraffin oil:

3 doses of 0.1 ml were injected into the skin on each side of the spine on a 4 x 2 cm scapular area using a needle (diameter: 0.50 x
16 m,. Terumo: C.M.L., 77140 Nemours, France) mounted on a 1 ml glass syringe (0.01 ml graduations, Record: Carrieri, 75005 Paris, France).
The animals from both groups received Freund's complete adjuvant at 50 % in an injectable isotonic solution of 0.9 % sodium chloride.
The animals from the control group received the vehicle alone whereas the animals from the treated group received the test substance suspended in
the vehicle. The third set of injections was a mixed suspension 50/50 (v/v) of Freund's complete adjuvant at 50 % in an injectable isotonic solution of 0.9 % sodium chloride, the vehicle to the control animals, or the test substance in the vehicle to the treated animals.

As the test substance in its original form did not show any irritant characteristics when administered by cutaneous application under an occlusive dressing during the preliminary test, local irritation was induced on day 7, using 0.5 ml of 10 % sodium laurylsulphate in vaseline, applied to the scapular region. On day 8, 0.5 ml of the vehicle in the control group or 500 mg of test substance in its original form in the treated group were prepared on a dry compress and then applied to the scapular region. They were held in place for 48 hours by means of an occlusive dressing. Any residual test substance was rinsed using a dressing moistened with water.

After a period of 12 days without treatment, a challenge cutaneous application of 0.5 ml of the vehicle (left flank) and 500 mg of the test substance in its original form (right flank) were prepared on a dry compress and then applied on all animals.

The substances were held in place for 24 hours by means of an occlusive dressing. Cutaneous reactions on the challenge application site were then evaluated 24 and 48 hours after removal of the dressing.


After the final scoring period, the animals were sacrificed and cutaneous samples were taken from the challenge application sites from all animals.
No histological examination was performed on the cutaneous samples.

Challenge controls:

After a period of 12 days without treatment, a challenge cutaneous application of 0.5 ml of the vehicle (left flank) and 500 mg of the test substance in its original form (right flank) were prepared on a dry compress and then applied on all animals.

Positive control substance(s):

not specified

Results and discussion

In vivo (non-LLNA)

Results

Results 1

Reading:

1st reading

Hours after challenge:

24

Group:

other: control

Dose level:

nr

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

No clinical signs or imortality were observed throughout the study

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: other: control. Dose level: nr. No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: No clinical signs or imortality were observed throughout the study.

Results 2

Reading:

2nd reading

Hours after challenge:

48

Group:

other: control

Dose level:

nr

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

No clinical signs or imortality were observed throughout the study

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: other: control. Dose level: nr. No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: No clinical signs or imortality were observed throughout the study.

Results 3

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

nr

No. with + reactions:

2

Total no. in group:

20

Clinical observations:

No clinical signs or imortality were observed throughout the study

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: nr. No with. + reactions: 2.0. Total no. in groups: 20.0. Clinical observations: No clinical signs or imortality were observed throughout the study.

Results 4

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

nr

No. with + reactions:

1

Total no. in group:

20

Clinical observations:

No clinical signs or imortality were observed throughout the study

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: nr. No with. + reactions: 1.0. Total no. in groups: 20.0. Clinical observations: No clinical signs or imortality were observed throughout the study.

Applicant's summary and conclusion

Executive summary:

In a dermal sensitisation study (Rhone-Poulenc, 1992) the sensitization potential of the test substance (E)-5[(4 - chlorophenyl)methylene]-2,2 - dimethylcyclopentanon was evaluated in 30 guinea-pigs by intradermal injection und cutaneous application, according to the maximization method of Magnusson and Kligman (Induction 5 % intracutaneous on day 1, Induction 100 % epicutaneous on day 8, Challenge 100 % epicutaneous on day 22) and OECD Guideline 406. Local irritation was induced on day 7, using 0.5 ml of 10 % sodium laurylsulphate in vaseline, applied to the scapular region.

No clinical signs were observed and no deaths occurred throughout the study. After the challenge application of the test substance, no coetaneous

reactions were observed in the animals of the control group. The body weight gain of the treated animals was unaffected by administration of the test substance. The macroscopic examination of' the skin at the challenge application sites revealed on the right flank of 2 treated animals an erythema after 24 and/or 48 hours. No edema was noted. The reactions noted (very slight erythema in one animal and well-defined erythema in one animal after 24 hours, very slight erythema in one animal after 48 hours) were considered to be due to a slight sensitization effect in 2/20 animals. After 48 hours, a dryness of the skin was also noted in 1/10 treated animals.

The test item was not a skin sensitizer in the present study.