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

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP and guideline conform study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2000

Report date:

2000

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.6 (Skin Sensitisation)

Deviations:

no

GLP compliance:

yes

Type of study:

guinea pig maximisation test

Test material

Test material information

Constituent 1

In vivo test system

Test animals

Species:

guinea pig

Strain:

Dunkin-Hartley

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Charles River Deutschland, Sulzfeld, Germany.
- Age and weight at study initiation: Young adult animals (approx. 5 weeks old, individual body weights < 500 grams) were selected.
- Housing: Group housing of 5 animals per labelled metal cage with wire-mesh floors and equipped with an
automatic drinking system (ITL, Bergen, The Netherlands).
- Diet (e.g. ad libitum): Free access to standard guinea pig diet, including ascorbic acid (1000 mg/kg); (Charles River Breeding and Maintenance Diet for Guinea Pigs, Altromin, Lage, Germany). Certificates of analysis were examined and retained in the NOTOX archives. Hay (B.M.I., Helmond, The
Netherlands) was provided once a week.
- Water (e.g. ad libitum): Free access to tap-water. Certificates of quarteriy analysis were examined and then retained in the NOTOX archives.
- Acclimation period: Acclimatisation period was at least 5 days before start of treatment under laboratory conditions.


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21°C
- Humidity (%): 30-70
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12

IN-LIFE DATES:
Start : 15 February 2000
End : 17 March 2000

Study design: in vivo (non-LLNA)

Induction

Induction 1

Route:

intradermal and epicutaneous

Vehicle:

propylene glycol

Induction 2

Concentration / amount:

50 %, 0,15 ml

Challenge

Challenge 1

Route:

epicutaneous, occlusive

Vehicle:

propylene glycol

Challenge 2

Concentration / amount:

50 %, 0,15 ml

No. of animals per dose:

Experimental group: 10 females.
Control group: 5 females.

Details on study design:

INDUCTION - Experimental animals
Day 1 The scapular region was clipped and three pairs of intradermal injections (0.1 ml/site)
were made in this area as follows:
A) A 1:1 w/w mixture of Freunds' Complete Adjuvant (Difco, Detroit, U.S.A.) with water
for injection (Fresenius AG, Bad Homburg, Germany).
B) The test substance at a 10% concentration.
C) A 1:1 w/w mixture of the test substance, at twice the concentration used in (B) and
Freunds' Complete Adjuvant.
Note: One of each pair was on each side of the midline and from cranial A) to caudal C).
Day 3 The dermal reactions caused by the intradermal injections were assessed for irritation.
Day 7 The scapular area between the injection sites was clipped and subsequently rubbed
with 10% sodium-dodecyl-sulfate (SDS, Boom, Meppel, The Netherlands) in vaseline
using a spatula. This concentration of SDS provokes a mild inflammatory reaction.
Day 8 The 10% SDS treated area between the injection sites was treated with 0.5 ml of a 50%
test substance concentration using a Metalline patch (2x3 cm) mounted on Medical
tape, which was held in place with Micropore tape and subsequently Coban elastic
bandage.
The dressing was removed after 48 hours exposure, the skin cleaned of residual test
substance using water and the dermal reactions caused by the epidermal exposure
were assessed for irritation.

INDUCTION - Control animals
The control animals were treated as described for the experimental animals except that,
instead of the test substance, vehicle alone was administered.

CHALLENGE - All animals
Day 21 One flank of all animals was clipped and treated by epidermal application of a 50% test
substance concentration and the vehicle (0.15 ml each), using Patch Test Plasters
(Leukotest®, Beiersdorf Medical, Almere, The Netherlands). The patches were held in
place with Micropore tape and subsequently Coban elastic bandage. The dressing was
removed after 24 hours exposure and the skin cleaned of residual test substance and
vehicle using water.
To remove the staining caused by the epidermal exposure to the test substance and to
facilitate scoring, the challenged areas of all animals were depilated in a similar manner
as described in the preliminary irritation test.
The treated sites were assessed for challenge reactions 24 and 48 hours after removal
of the dressing.

Positive control substance(s):

no

Results and discussion

In vivo (non-LLNA)

Results

Results 1

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

0%

No. with + reactions:

0

Total no. in group:

5

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. Dose level: 0%. No with. + reactions: 0.0. Total no. in groups: 5.0.

Results 2

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

50%

No. with + reactions:

0

Total no. in group:

10

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 50%. No with. + reactions: 0.0. Total no. in groups: 10.0.

Results 3

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

0%

No. with + reactions:

0

Total no. in group:

5

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: negative control. Dose level: 0%. No with. + reactions: 0.0. Total no. in groups: 5.0.

Results 4

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

50%

No. with + reactions:

0

Total no. in group:

10

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: 10.0.

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information

Conclusions:

There was no evidence that TKP 50048 had caused skin hypersensitivity in the guinea pig, since no responses were observed in the experimental animals in the challenge phase. This result indicates a sensitisation rate of 0 per cent.

Executive summary:

Test substance concentrations selected for the main study were based on the results of a preliminary study. In the main study, ten experimental animals were intradermally injected with a 10% concentration and epidermally exposed to a 50% concentration. Five control animals were similarly treated, but with vehicle alone (propylene glycol). Approximately 24 hours before the epidermal induction exposure all animals were treated with 10% SDS.

Two weeks after the epidermal application all animals were challenged with a 50% test substance concentration and the vehicle.

No skin reactions were evident after the challenge exposure in the experimental and control animals. Red staining was observed at the test substance treated skin sites, 24 and 48 hours after challenge. This staining did not hamper the scoring of the skin reactions.

There was no evidence that TKP 50048 had caused skin hypersensitivity in the guinea pig, since no responses were observed in the experimental animals in the challenge phase.

This result indicates a sensitisation rate of 0 per cent.

Based on these results and according to the EC criteria for classification and labelling requirements for dangerous substances and preparations (Guidelines in Commission Directive 93/21/EEC), TKP 50048 does not have to be classified and has no obligatory labelling requirement for sensitisation by skin contact.