Pyrrolo[3,4-c]pyrrole-1,4-dione, 3,6-bis([1,1'-biphenyl]-4-yl)-2,5-dihydro-

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)

Rationale for reliability incl. deficiencies:

other: GLP and OECD testing guideline compliant study with well characterized test material

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1993

Report date:

1993

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Deviations:

no

GLP compliance:

yes

Type of study:

guinea pig maximisation test

Test material

Test material information

Constituent 1

Details on test material:

- Substance type: Organic
- Physical state: Solid
- Lot/batch No.: Z-2281/1,2,4,5
- Expiration date of the lot/batch: April 01, 1997
- Storage condition of test material: at room temperature in the dark

In vivo test system

Test animals

Species:

guinea pig

Strain:

Himalayan

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: BRL Ltd., Basel, Switzerland
- Age at study initiation: Approx. 8 weeks
- Weight at study initiation: 318 - 450 grams
- Housing: 2 animals per cage
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: 5 days

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

IN-LIFE DATES: From: 1992-09-15 To: 1992-10-16

Study design: in vivo (non-LLNA)

Induction

Induction 1

Route:

intradermal and epicutaneous

Vehicle:

other: vaseline

Induction 2

Concentration / amount:

Intradermal injections:
a) The test substance suspended to 5% (w/w) with polyethylene glycol,
b) The test substance, a similar concentration as used In (A), and Freunds' Complete Adjuvant, 0.05 ml of each solution per site separately*.

Epidermal applications
50% in vaseline (induction)
10, 25, 50% (challenge)

Challenge

Challenge 1

Route:

epicutaneous, semiocclusive

Vehicle:

other: vaseline

Challenge 2

Concentration / amount:

Intradermal injections:
a) The test substance suspended to 5% (w/w) with polyethylene glycol,
b) The test substance, a similar concentration as used In (A), and Freunds' Complete Adjuvant, 0.05 ml of each solution per site separately*.

Epidermal applications
50% in vaseline (induction)
10, 25, 50% (challenge)

No. of animals per dose:

20 (test item)
10 (control)

Details on study design:

Prior to each intradermal treatment, the test substance was weighed into small
glass containers, polyethylene glycol was added (w/w) and subsequently mixed
using a mechanical stirrer and/or spatula.

Doses were chosen based on a preliminary study.
Prior to each epidermal treatment, the test substance was weighed into a
mortar, vaseline was added (w/w) and subsequently mixed using a pestle.

On day 7, approximately 24 hours prior to the epidermal induction application,
the scapular area (approximately 6 x 8 cm) was clipped and shaved free of
hair, and pretreated with 10 % Sodium-Dodecyl-Sulfate (SDS) in vaseline.
The SDS was massaged into the skin with a spatula without bandaging. This
concentration of SDS enhances sensitisation by provoking a mild inflammatory
reaction.

All animals were sacrificed after the termination of observation by carbon
dioxide asphyxiation. Immediately thereafter, the four challenge treated skin
areas of the last challenge were cut using a surgical scissor. Each skin site
was collected in a coded, perforated small cassette and per animal fixed in
neutral phosphate buffered 4% formaldehyde solution.
Sections were cut from the skin sites of experimental and control animals
treated with the highest test substance concentration and with the vehicle.
The sections were stained with haematoxylin and eosin. At least one section
from each skin site was microscopically examined by a pathologist.
No microscopically examination was performed on the skin sites treated with
the intermediate concentrations of experimental and control animals.

Challenge controls:

vehicle

Positive control substance(s):

yes

Remarks:

Formaldehyde

Results and discussion

Positive control results:

Clearly positive results were observed in the experimental animals after the challenge with 0.2% (w/w) FORMALDEHYDE in distilled water.

In vivo (non-LLNA)

Results

Results 1

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

50%

No. with + reactions:

0

Total no. in group:

20

Clinical observations:

Histopathological examination revealed no treatment related differences between the 50% test substance concentration treated- and control-skin areas in both experimental and control animals.

Remarks on result:

other: see Remark

Remarks:

Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 50% . No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: Histopathological examination revealed no treatment related differences between the 50% test substance concentration treated- and control-skin areas in both experimental and control animals. .

Results 2

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

50%

No. with + reactions:

0

Total no. in group:

20

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 50%. No with. + reactions: 0.0. Total no. in groups: 20.0.

Results 3

Reading:

other: 1st and second reading

Hours after challenge:

24

Group:

negative control

Dose level:

0

No. with + reactions:

0

Total no. in group:

10

Remarks on result:

other: Reading: other: 1st and second reading. . Hours after challenge: 24.0. Group: negative control. Dose level: 0. No with. + reactions: 0.0. Total no. in groups: 10.0.

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information