2,2'-Methylenebis(4-aminophenol) dihydrochloride

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: According to the OECD Guideline and GLP

Data source

Reference

Reference 1

Reference Type:

study report

Title:

Unnamed

Year:

1998

Report date:

1998

Reference 2

Reference Type:

other: abstract

Title:

Unnamed

Year:

1999

Report date:

1999

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: EC-Guideline 93/21

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

other: EC-Guideline 92/69, B.6.

GLP compliance:

yes (incl. QA statement)

Type of study:

Buehler test

Test material

Test material information

Constituent 1

Reference substance name:

-

EC Number:

440-850-3

EC Name:

-

Cas Number:

27311-52-0

Molecular formula:

C13H14N2O2.2ClH

IUPAC Name:

4-amino-2-[(5-amino-2-hydroxyphenyl)methyl]phenol dihydrochloride

Constituent 2

Reference substance name:

[TN]Ro 1525[/TN][SPEC]Powder[/SPEC][AM]99 %[/AM]

IUPAC Name:

[TN]Ro 1525[/TN][SPEC]Powder[/SPEC][AM]99 %[/AM]

Details on test material:

Ro 1525 corresponds to Colipa A 155
SAT 980375
Batch-No.: Ro-Rn 6567-083
Description: light grey powder

In vivo test system

Test animals

Species:

guinea pig

Strain:

Dunkin-Hartley

Sex:

female

Study design: in vivo (non-LLNA)

Induction

Induction 1

Route:

epicutaneous, occlusive

Vehicle:

other: white petrolatum

Induction 2

Concentration / amount:

50 % of "Ro 1525" in white petrolatum was the highest technically feasible concentration.

Challenge

Challenge 1

Route:

epicutaneous, occlusive

Vehicle:

other: white petrolatum

Challenge 2

Concentration / amount:

50 % of "Ro 1525" in white petrolatum was the highest technically feasible concentration.

No. of animals per dose:

20 animals for the test substance group
10 animals for the negative control group

Details on study design:

1st application: Induction 50 % occlusive epicutaneous
2nd application: Induction 50 % occlusive epicutaneous
3rd application: Challenge 50 % occlusive epicutaneous

I 3 induction exposures
If left flank
ch chaJlenge exposure
arf anterior fight flank
TS test substance
prf posterior right flank

group animal Nos. sex exposure substances
K 1-10 f I lf white petrolatum
negative Ch prf TS, 50% in white petrolatum
control arf white petrolatum
___________________________________________________________________

A 11-30 f I lf TS, 50% in white petrolatum
test Ch prf TS, 50% in white petrolatum
substance arf white petrolatum

Positive control substance(s):

yes

Remarks:

HEXYL CINNAMIC ALDEHYDE

Results and discussion

Positive control results:

17/20 animals, i.e. 85 % of the animals of the positive control group, were regarded as sensitised.

In vivo (non-LLNA)

Results

Results 1

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

50% (induction+challenge)

No. with + reactions:

1

Total no. in group:

20

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 50% (induction+challenge). No with. + reactions: 1.0. Total no. in groups: 20.0.

Results 2

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

50% (induction+challenge)

No. with + reactions:

1

Total no. in group:

20

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 50% (induction+challenge). No with. + reactions: 1.0. Total no. in groups: 20.0.

Results 3

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

0% (induction), 0% and 50% (challenge)

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: 0% (induction), 0% and 50% (challenge). No with. + reactions: 0.0. Total no. in groups: 10.0.

Results 4

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

0% (induction), 0% and 50% (challenge)

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: 0% (induction), 0% and 50% (challenge). No with. + reactions: 0.0. Total no. in groups: 10.0.

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

In the negative control group, the control areas and also the test substance treated areas of all animals were normal 24 and 48 hours after the end of the challenge exposure. In the test substance group, a well defined skin reaction was noted in 1/20 animals at the test substance treated area 24 hours and 48 hours after the end of the challenge exposure. The control areas of all animals were normal of each scoring time. Therefore 1/20 animals (5 % of the test substance group animals) was regarded as sensitised. The threshold limit for a classification of a test substance as a sensitiser is 15 %
positively reacting animals in the Buehler test according to the EC Guideline 93/21. As this threshold is not reached, the test substance "Ro 1525" is
not considered to be a sensitiser.

Executive summary:

The "Buehler test" of E.V. Buehler was performed to reveal a possible sensitising potential of "Ro 1525". Investigations performed were in conformance with OECD-Guideline 406 and EGGuideline 92/69, B.6. Twenty female guinea pigs were used as a test substance group and

another 10 females were used as a negative control group. There were three epicutaneous induction exposures and one epicutaneous challenge exposure. The concentration of the test substance was 50 % in white petrolatum for all three induction exposures and for the challenge exposure. The areas of administration were covered occlusively for 6 hours.

Results - General

All animals survived till the end of the study. Possible skin reactions excluded, no other adverse effects were noted. The test substance did not stain the skin of the guinea pigs and scoring was not impeded by skin dyeing.

Skin reactions afer induction exposures

The application sites of all control animals were normal at each time. In the test substance group, very slight to well defined erythema and/or oedema were noted in 3/20 animals after the second and/or third induction exposure.

Skin reactions after challenge exposure

In the negative control group, the control areas and also the test substance treated areas of all animals were normal 24 and 48 hours after the end of the challenge exposure. In the test substance group, a well defined skin reaction was noted in 1/20 animals at the test substance treated area 24 hours and 48 hours after the end of the challenge exposure. Therefore one animal(5 % of the test substance group animals) was regarded as sensitised. The threshold limit for a classification of a test substance as a sensitiser is 15 % positively reacting animals in the Buehler test according to the EC Guideline 93/21. As this threshold is not reached, the test substance "Ro 1525" is not considered to be a sensitiser.