Benzonitrile, 4-[(1,6-dihydro-4-hydroxy-6-oxo-2-pyrimidinyl)amino]-

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2003-05-20 to 2003-06-11

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2004

Report date:

2004

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)

Deviations:

not specified

Remarks:

not specified/limited data provided on methodology

Principles of method if other than guideline:

SPL Standard Test Method 595.12

GLP compliance:

no

Remarks:

The study was conducted in a facility operating to Good Laboratory Practice within the UK national GLP monitoring programme, but the study report has not been audited by the QA unit. No formal claim of GLP compliance is made for this study.

Type of study:

mouse local lymph node assay (LLNA)

Test material

Test material information

Constituent 1

Reference substance name:

4-[(4,6-dihydroxypyrimidin-2-yl)amino]benzonitrile

EC Number:

609-425-1

Cas Number:

374067-80-8

Molecular formula:

C11H8N4O2

IUPAC Name:

4-[(4,6-dihydroxypyrimidin-2-yl)amino]benzonitrile

Test material form:

solid: particulate/powder

Details on test material:

- Name of test material (as cited in study report): JNJ-4370561-AAA (T002326)
- Physical state: solid (powder)
- Appearance: slight beige powder

In vivo test system

Test animals

Species:

mouse

Strain:

CBA/Ca

Sex:

not specified

Details on test animals and environmental conditions:

TEST ANIMALS: no data

ENVIRONMENTAL CONDITIONS: no data

Study design: in vivo (LLNA)

Vehicle:

dimethyl sulphoxide

Concentration:

2.5, 5, and 10% w/w

No. of animals per dose:

4

Details on study design:

RANGE FINDING TESTS:
- Compound solubility: no data
- Irritation: Following a preliminary sighting test, no death or signs of systemic toxicity were observed at a concentration of 10% w/w in DMSO.
- Lymph node proliferation response: no data


MAIN STUDY
ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method: LLNA
- Criteria used to consider a positive response: Test to control ratio for stimulation Index greater than 3.0 indicates a 'positive' result


TREATMENT PREPARATION AND ADMINISTRATION:
- three groups of four animals were treated with 25 µL per ear of 2.5, 5, and 10% test material in dimethyl sulfoxide. A further group of four animals was treated with dimethyl sulfoxide alone. Determination of lymphocyte proliferation was quantified by measuring the incorporation of radiolabelled thymidine in the dividing lymph node cells. The proliferation response of the lymph node cells was expressed as the number of radioactive disintegrations per minute per lymph node and as the ratio of ³HTdR incorporation into lymph node cells of test nodes relative to that recorded for the control nodes (Stimulation Index).

Positive control substance(s):

hexyl cinnamic aldehyde (CAS No 101-86-0)

Results and discussion

Positive control results:

see: any other information on results (here below)

In vivo (LLNA)

Results

Results 1

Parameter:

SI

Value:

2.05

Test group / Remarks:

2.5% w/w group

Results 2

Parameter:

SI

Value:

1.67

Test group / Remarks:

5% w/w group

Results 3

Parameter:

SI

Value:

1.95

Test group / Remarks:

10% w/w group

Cellular proliferation data / Observations:

CELLULAR PROLIFERATION DATA: no data

DETAILS ON STIMULATION INDEX CALCULATION: The Stimulation Index (SI) was expresssed as the mean radioactive incorporation for each treatment group divided by the mean radioactive incorporation of the vehicle control group.

EC3 CALCULATION: no data

CLINICAL OBSERVATIONS: no data

BODY WEIGHTS: no data

Any other information on results incl. tables

Positive Control Local Lymph Node Assay in the Mouse (2003)

Start Date	Finish Date	Test Material	Concentration	Vehicle	Stimulation Index^a	Classification^b
13/03/2003	19/03/2003	α‑Hexylcinnamaldehyde, tech., 85%	5%, 10%, 25% v/v	acetone/olive oil 4:1	2.8, 2.3, 5.5	Positive
13/03/2003	19/03/2003	α‑Hexylcinnamaldehyde, tech., 85%	5%, 10%, 25% v/v	acetone/olive oil 4:1	2.0, 1.9, 6.8	Positive
10/10/2003	16/10/2003	α‑Hexylcinnamaldehyde, tech., 85%	5%, 10%, 25% v/v	acetone/olive oil 4:1	1.76, 2.78, 5.06	Positive
16/10/2003	22/10/2003	α‑Hexylcinnamaldehyde, tech., 85%	5%, 10%, 25% v/v	acetone/olive oil 4:1	1.49, 1.73, 5.26	Positive

 

a=        Ratio of test to control lymphocyte proliferation

b=        Stimulation index greater than 3.0 indicates a positive result

* =        Standard Test Method 595 (Pooled nodes)

·=        Standard Test Method 599 (Individual nodes)

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The test substance was not considered to be a skin sensitizer as the test to control ratio for the stimulation index didn't exceed 3.0 in all dose groups.