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

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1995-01-04 to 1995-01-30

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP and guideline study

Qualifier:

according to guideline

Guideline:

EU Method B.6 (Skin Sensitisation)

Version / remarks:

92/69/EEC, 31-Jul-1992

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Version / remarks:

adopted July 17, 1992

Deviations:

no

GLP compliance:

yes

Type of study:

guinea pig maximisation test

Species:

guinea pig

Strain:

other: Himalayan spotted

Sex:

male

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: BRL, Biological Research Laboratories Ltd., Wölferstrasse 4, 4414 Füllinsdorf/Switzerland
- Age at study initiation: 5 - 7 weeks
- Weight at study initiation: 317 - 427 g
- Housing: Individually in Makrolon type-3 cages with autoclaved standard softwood bedding ("Lignocel", Schill AG, CH-4132 Muttenz).
- Diet: Pelleted standard Kliba 342, batch no. 66/94 guinea pig breeding/maintenance diet ("Kliba", Klingentalmuhie AG, CH-4303 Kaiseraugst), ad libitum.
- Water: Community tap water from Füllinsdorf, ad libitum.
- Acclimation period: One week for the control and test group under test conditions after health examination.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20-22
- Humidity (%): 51-68
- Air changes (per hr): 10-15
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 1994-12-28 To: 1995-01-30

Route:

intradermal and epicutaneous

Vehicle:

other: ethanol

Concentration / amount:

Induction:
intradermal: 5%
epidermal: 25%

Challenge:
epidermal: 25%

Route:

epicutaneous, occlusive

Vehicle:

other: ethanol

Concentration / amount:

Induction:
intradermal: 5%
epidermal: 25%

Challenge:
epidermal: 25%

No. of animals per dose:

Test group: 20
Control group: 10

Details on study design:

RANGE FINDING TESTS:
The objective of this investigation was to identify a maximally tolerated concentration of the test article suitable for the induction phase of the main
study. In addition, a suitable non-irritant concentration of the test article, by the topical route of administration, was identified for the challenge application.

MAIN STUDY
A.1 INDUCTION EXPOSURE -intradermal
- No. of exposures: one, on test day 1
- Exposure period: single treatment
- Test groups (2 injections each):
1) 1:1 (v/v) mixture of Freund's Complete Adjuvant and physiological saline.
2) The test article, diluted to 5% with ethanol.
3) The test article diluted to 5% by emulsion in a 1:1 (v/v) mixture of Freund's Complete Adjuvant and physiological saline.
- Control group (2 injections each):
1) 1:1 (v/v) mixture of Freund's Complete Adjuvant and physiological saline.
2) ethanol
3) 1:1 (w/w) mixture of ethanol in a 1:1 (v/v) mixture of Freund's Complete Adjuvant and physiological saline.
- Site: scapular region
- Concentration: 5 % in ethanol

A.2 INDUCTION EXPOSURE-epidermal
- No. of exposures: one
- Exposure period: start on test day 8 for 48 h
- Pretreatment: 10% Sodium-Lauryl-Sulfate (SLS)
- Test groups: 2 x 4 cm patch of filter paper was saturated with the test article (25% in ethanol)
- Control group: 2 x 4 cm patch of filter paper was saturated with the test vehicle (ethanol)
- Site: scapular area
- Concentration: 25 % in ethanol

B. CHALLENGE EXPOSURE
- No. of exposures: one
- Day of challenge: performed on test day 22
- Exposure period: 24 h
- Test groups: Two patches ( 2 x 2 cm) of filter paper were saturated with the highest non-irritating concentration of 25% (left flank) and the vehicle only (right flank)
- Control group: same as test group
- Site: flank
- Concentration: 25 % in ethanol
- Evaluation (hr after challenge): 24 and 48

Challenge controls:

none

Positive control substance(s):

yes

Remarks:

2-Mercaptobenzothiazol and Benzocaine

Positive control results:

Following treatment (challenge) with 25% 2-Mercaptobenzothiazol or 25% Benzocaine in mineral oil 60% 60% of the animals were positive in the GPMT, indicating the sensitivity of the test system used for sensitisation assessment.

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

25 %

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: 25 %. No with. + reactions: 0.0. Total no. in groups: 10.0.

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

25 %

No. with + reactions:

0

Total no. in group:

20

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 25 %. No with. + reactions: 0.0. Total no. in groups: 20.0.

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

25 %

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: 25 %. No with. + reactions: 0.0. Total no. in groups: 10.0.

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

25 %

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: 25 %. No with. + reactions: 0.0. Total no. in groups: 20.0.

Interpretation of results:

not sensitising

Remarks:

Migrated information

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

Procedure and results

To evaluate the allergic potential of the substance, a skin maximisation test in guinea-pig was perfomed. Ten test and ten control guinea-pigs were used in this study. For induction the animals were treated intradermally (5%). 6 days later, topical induction (25%) in the same area was performed after treatment with sodium lauryl sulphate in petrolatum. Control and test animals were challenged topically two weeks after the topical induction application using the test substance, 50% w/v in distilled water.

No skin reactions or signs of toxicity were recorded. There were no dermal reactions seen in any of the test animals.

Discussion

The test substance did not induce any dermal reactions in test animals. Thus, the test substance is considered to be a non-sensitizer.

Migrated from Short description of key information:
To evaluate the allergic potential of the test substance, a skin maximisation test (EU B.6, GLP) in guinea-pig was perfomed. The test item did not induce any dermal reactions in test animals. Thus, the test substance is considered to be a non-sensitizer.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Dangerous Substance Directive (67/548/EEC)

The available studies are considered reliable and suitable for classification purposes under 67/548/EEC. As a result the substance is not considered to be classified for skin sensitization under Directive 67/548/EEC.

                               

Classification, Labeling, and Packaging Regulation (EC) No. 1272/2008

The available experimental test data are reliable and suitable for classification purposes under Regulation 1272/2008. As a result the substance is not considered to be classified for skin sensitization under Regulation (EC) No. 1272/2008.