4-bromo-2,2-diphenylbutyric acid

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2004-02-02 to 2004-02-18

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study without detailed documentation

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2004

Report date:

2004

Materials and methods

Test guideline

Test guideline 1

Qualifier:

equivalent or similar to guideline

Guideline:

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

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: SPL Standard Test Method 595.12

Deviations:

no

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-bromo-2,2-diphenylbutyric acid

EC Number:

253-648-3

EC Name:

4-bromo-2,2-diphenylbutyric acid

Cas Number:

37742-98-6

Molecular formula:

C16H15BrO2

IUPAC Name:

4-bromo-2,2-diphenylbutanoic acid

Test material form:

solid: particulate/powder

Details on test material:

- Name of test material (as cited in study report): JNJ-1580774-AAA (T000835)
- Physical state: solid powder
- Appearance: slight beige

Specific details on test material used for the study:

no data

In vivo test system

Test animals

Species:

mouse

Strain:

CBA/Ca

Sex:

not specified

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: no data
- Age at study initiation: no data
- Weight at study initiation: no data
- Housing: no data
- Diet (e.g. ad libitum): no data
- Water (e.g. ad libitum): no data
- Acclimation period: no data


ENVIRONMENTAL CONDITIONS
- Temperature (deg C): no data
- Humidity (%): no data
- Air changes (per hr): no data
- Photoperiod (hrs dark / hrs light): no data


IN-LIFE DATES: From: 2004-02-02 To: 2004-02-18

Study design: in vivo (LLNA)

Vehicle:

dimethylformamide

Concentration:

10%, 25%, 50% w/w

No. of animals per dose:

4

Details on study design:

PRE-SCREEN TESTS:
- Compound solubility: no data
- Irritation: no systemic toxicity at 50% w/w
- Lymph node proliferation response: no data

MAIN STUDY
ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method: LLNA: - Lymphocyte proliferation is quantified by measuring the incorporation of radiolabelled thymidine in the dividing lymph node cells. The proliferation response of lymph node cells was expressed as the number of radioactive disintegrations per minute per lymph node (dpm/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).
- Criteria used to consider a positive response: stimulation index: Test to control ratio greater than 3.0 indicates a ‘positive’ result

TREATMENT PREPARATION AND ADMINISTRATION:
- 3 groups of 4 animals were treated with 50 uL test material (25 uL per ear), as a solution of dimethyl formamide, at 10, 25 and 50% w/w.
- A further group was treated with dimethyl formamide alone.

Positive control substance(s):

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

other: 2,4-Dinitrobenzenesulfonic acid, sodium salt 1%, 10%, 20% v/v in 1% pluronic F-68 in distilled water

Statistics:

no data

Results and discussion

Positive control results:

See Any other information on results incl. tables

In vivo (LLNA)

Results

Results 1

Parameter:

SI

Value:

1.02

Test group / Remarks:

10% w/w group

Results 2

Parameter:

SI

Value:

2.2

Test group / Remarks:

25% w/w group

Results 3

Parameter:

SI

Value:

3.06

Test group / Remarks:

50% w/w group

Cellular proliferation data / Observations:

CELLULAR PROLIFERATION DATA: no data

DETAILS ON STIMULATION INDEX CALCULATION: see Results

EC3 CALCULATION: Using the data generated, an EC3 value of 48.3% was calculated.

CLINICAL OBSERVATIONS: no data

BODY WEIGHTS : no data

Any other information on results incl. tables

Positive Control Local Lymph Node Assay in the Mouse (2004)

Project Number	Start Date	Finish Date	Test Material	Concentration	Vehicle	Stimulation Index^a	Classification^b
039/687·	29/04/2004	05/05/2004	α‑Hexylcinnamaldehyde, tech., 85%	5%, 10%, 25% v/v	acetone/olive oil 4:1	1.40, 2.23, 6.09	Positive
039/688*	29/04/2004	05/05/2004	α‑Hexylcinnamaldehyde, tech., 85%	5%, 10%, 25% v/v	acetone/olive oil 4:1	1.74, 2.20, 8.89	Positive
039/719*	14/10/2004	26/10/2004	α‑Hexylcinnamaldehyde, tech., 85%	5%, 10%, 25% v/v	tetrahydrofuran	1.97, 3.71, 7.82	Positive
039/720*	29/09/2004	05/10/2004	2,4‑Dinitrobenzenesulfonic acid, sodium salt	1%, 10%, 20% v/v	1% pluronic F-68 in distilled water	1.03, 4.41, 13.55	Positive
039/723*	27/10/2004	02/11/2004	α‑Hexylcinnamaldehyde, tech., 85%	10%, 25%, 50% v/v	cottonseed oil	1.52, 2.63, 5.07	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:

Category 1B (indication of skin sensitising potential) based on GHS criteria

Conclusions:

The test item was considered to be a sensitiser under the conditions of the test. Based on the EC3 value of 48.3% and the CLP criteria, the substance is classified as skin sensitiser category 1B.