Methyl 4-[[(2,5-dichlorophenyl)amino]carbonyl]-2-nitrobenzoate

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: guideline study (OECD TG 429), with GLP

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2007

Report date:

2007

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes

Type of study:

mouse local lymph node assay (LLNA)

Test material

Test material information

Constituent 1

Reference substance name:

Methyl 4-[[(2,5-dichlorophenyl)amino]carbonyl]-2-nitrobenzoate

EC Number:

281-339-3

EC Name:

Methyl 4-[[(2,5-dichlorophenyl)amino]carbonyl]-2-nitrobenzoate

Cas Number:

83929-47-9

Molecular formula:

C15H10Cl2N2O5

IUPAC Name:

methyl 4-[(2,5-dichlorophenyl)carbamoyl]-2-nitrobenzoate

Details on test material:

- Name of test material (as cited in study report): Nitro-MMT-Dichloranilide

In vivo test system

Test animals

Species:

mouse

Strain:

CBA

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- strain: CBA/CaOlaHsd
- Source: Harlan Netherlands
- Age at study initiation: 7-8 weeks
- Weight at study initiation: mean 18.8 g +/- 1.1 g (range 17.7-21.4 g)
- Housing: individually, Makkrolon Type I cages
- Diet: pelleted standard died (Harlan Winkelmann, Borchen), ad libitum
- Water: tap water, ad libitum
- Acclimation: yes (no information on duration)

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/- 3
- Humidity (%): 30-92
- Photoperiod (hrs dark / hrs light): 12 hrs/12 hrs

Study design: in vivo (LLNA)

Vehicle:

dimethyl sulphoxide

Concentration:

0, 5, 10, 20% (w/v)

No. of animals per dose:

4 females per dose group
2 females in the pre-test

Details on study design:

RANGE FINDING TESTS:
- Compound solubility: 20% (w/v) suspension in DMSO was the highest technically applicable concentration; higher concentrations could also not be achieved with other vehicles
- Irritation: No irritation effects were observed after tripple application of test item concentrations of 2.5, 5. 10, and 20% (w/v).
- lymph node proliferation response: no data


MAIN STUDY
ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method: LLNA
- Criteria used to consider a positive response:
1: exposure to at least one concentration of the test item resulted in an incorporation of 3H-methyl thymidine at least 3-fold or greater than that recorded in control mice as indicated by the stimulation index
2: data are compatible with a conventional dose response, although allowance must be made for either local toxicity or immunological suppression especially at high topical concentrations

TREATMENT PREPARATION AND ADMINISTRATION:
- individual preparation of weight volume dilutions using a magnetic stirrer as homogenizer
- test item preparations were made freshly before each dosing occasion
- 25 µl were spread over the entire dorsal surface of each ear lobe once daily for three consecutive days

Positive control substance(s):

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

Statistics:

- calculations of mean values and standard deviations for body weight

Results and discussion

Positive control results:

Stimulation indices of 2.43, 4.07 and 4.88 were determined with the positve control substance at concentrations of 5%, 10% and 25% (w/v), respectively, in acetone:olive oil (4+1). An EC3 value of 6.7% (w/v) was calculated.

In vivo (LLNA)

Results

Results 1

Parameter:

SI

Remarks on result:

other: Stimulation indices were all below 3. The following SI were calcualted: 5% test item: 2.2 10. % test item: 1.5 20% test item: 0.8

Results 2

Parameter:

other: disintegrations per minute (DPM)

Remarks on result:

other: see Remark

Remarks:

There was no dose dependent increase in the dpm, which were measured for the pooled lymph nodes of each treatment group (8 lymph nodes per dose group): Background: 24 or 20 dpm Control group: 6360 dpm 5% test item: 13779 dpm 10% test item: 9638 dpm 20% test item: 4931 dpm

Any other information on results incl. tables

The animals did not show any clinical signs (neither local toxicity nor systemic findings) during the course of the study and no cases of mortality were observed. The body weights of the animals were within the range commonly recorded for animals of this strain. Calculation of the EC3 value was not performed, because no test concentration produced a SI of 3 or higher.

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information Criteria used for interpretation of results: other: CLP

Conclusions:

The test substance was not sensitising in this LLNA in concentrations up to 20% (w/v) in DMSO, the highest technically achievable concentration.

Executive summary:

The test item was assessed for its possible contact allergenic potential in a local lymph node assay (OECD TG 429). For this purpose the test item was applied to the dorsal surface of the ears of female mice (4 per group) at concentrations of 5, 10, and 20% (w/v) in dimethyl sulphoxide for three consecutive days. The animals did not show any clinical signs during the course of the study and no cases of mortality were observed. In this study Stimulation Indices (S.I.) of 2.2, 1.5, and 0.8 were determined with the test item at concentrations of 5, 10, and 20%, respectively. The results obtained with the positive control confirmed the validity of the test. The test item was not a skin sensitiser in this assay.