4-amino-2,5-dimethoxy-N-methylbenzenesulphonamide

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2008

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: well performed OECD study with GLP

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2008

Report date:

2008

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:

4-amino-2,5-dimethoxy-N-methylbenzenesulphonamide

EC Number:

256-435-3

EC Name:

4-amino-2,5-dimethoxy-N-methylbenzenesulphonamide

Cas Number:

49701-24-8

Molecular formula:

C9H14N2O4S

IUPAC Name:

4-amino-2,5-dimethoxy-N-methylbenzene-1-sulfonamide

Details on test material:

purity: 92.5 %

In vivo test system

Test animals

Species:

mouse

Strain:

other: CBA/CaOlaHsd

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Harlan Netherlands, B.V. Postbus 6174, NL - 5960 AD Horst / The Netherlands
- Age at study initiation: 8 - 9 weeks
- Weight at study initiation: 18.8 - 22.7 g
- Housing: single; Makrolon Type I cages, with wire mesh top, granulated soft wood bedding
- Diet: pelleted standard diet, ad libitum (Harlan Winkelmann GmbH, D-33178 Borchen)
- Water: tap water, ad libitum,
- Acclimation period: At least 5 days prior to the start of dosing under test conditions after health examination.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22+-3
- Humidity (%): 30 - 70
- Air changes (per hr):
- Photoperiod: artificial light 6.00 a.m. - 6.00 p.m.

Study design: in vivo (LLNA)

Vehicle:

dimethyl sulphoxide

Concentration:

0, 2.5, 5, 10 %

No. of animals per dose:

4

Positive control substance(s):

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

Results and discussion

Positive control results:

Positive control with alpha -Hexylcinnamaldehyde in acetone:olive oil (4+1) yielded in an EC3 value 9.9 .

In vivo (LLNA)

Results

Results 1

Parameter:

SI

Remarks on result:

other: see above

Results 2

Parameter:

other: disintegrations per minute (DPM)

Remarks on result:

other: see Remark

Remarks:

Vehicle: dimethylsulfoxide Test item Calculation Result concentration Group Measurement DPM-BG number of DPM per (%) DPM lymph nodes lymph node S.I --- BGI 59 --- --- --- --- --- BGII 59 --- --- --- --- --- 1 8322 8267 8 1033.3 2.5 2 8497 8442 8 1055.2 1.02 5 3 8367 8312 8 1038.9 1.01 10 4 10390 10335 8 1291.8 1.25 BG = Background (1 ml 5% trichloroacetic acid) in duplicate The EC3 value could not be calculated, since all S.I.´s are below 3.

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The test item Chinonbasesulfmethylamide TF was found to be not a skin sensitiser under the described conditions.

Executive summary:

In order to study a possible contact allergenic potential of Chinonbasesulfmethylamide TF, three groups each of four female mice were treated daily with the test item at concentrations of 2.5, 5, and 10% (w/v) in dimethylsulfoxide by topical application to the dorsum of each ear lobe (left and right) for three consecutive days. A control group of four mice was treated with the vehicle (dimethylsulfoxide) only. Five days after the first topical application the mice were injected intravenously into a tail vein with radio-labelled

thymidine (3H-methyl thymidine). Approximately five hours after intravenous injection, the mice were sacrificed, the draining auricular lymph nodes excised and pooled per group.

Single cell suspensions of lymph node cells were prepared from pooled lymph nodes, which were subsequently washed and incubated with trichloroacetic acid overnight. The proliferative capacity of pooled lymph node cells was determined by the incorporation of

3H-methyl thymidine measured in a ß-scintillation counter.

All treated animals survived the scheduled study period and no signs of toxicity were observed.

A test item is regarded as a sensitiser in the LLNA if the exposure to one or more test concentration resulted in 3-fold or greater increase in incorporation of 3HTdR compared with concurrent controls, as indicated by the Stimulation Index (S.I.). The estimated

concentration of test item required to produce a S.I. of 3 is referred to as the EC3 value.

In this study Stimulation Indices of 1.02, 1.01 and 1.25 were determined with the test item at concentrations of 2.5, 5, and 10% in dimethylsulfoxide.

The EC3 value could not be calculated, since none of the tested concentrations induced an S.I. greater than 3