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Administrative data

Endpoint:
skin sensitisation: in vivo (LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2007
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:
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

Constituent 1
Chemical structure
Reference substance name:
Sodium p-(3-amino-4-methylbenzamido)benzenesulphonate
EC Number:
275-177-2
EC Name:
Sodium p-(3-amino-4-methylbenzamido)benzenesulphonate
Cas Number:
71077-34-4
Molecular formula:
C14H14N2O4S.Na
IUPAC Name:
sodium 4-[(3-amino-4-methylbenzoyl)amino]benzenesulfonate

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: 7 - 8 weeks
- Weight at study initiation: 19.4 - 20.3 grams
- Housing: single in Makrolon Type I cages, with wire mesh top
- Bedding: granulated soft wood bedding
- Diet: pelleted standard diet, ad libitum; (Harlan Winkelmann GmbH, D-33178 Borchen)
- Water: tap water, ad libitum

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22+-3
- Humidity (%): 30 - 79
- Photoperiod: artificial light 6.00 a.m. - 6.00 p.m.

Study design: in vivo (LLNA)

Vehicle:
dimethyl sulphoxide
Concentration:
0, 6.25, 1.5, 25%
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 substance: -Hexylcinnamaldehyde
Vehicle: acetone:olive oil (4+1):

Test item Group Measurement Calculation Result
concentration DPM DPM-BG number of DPM per
lymph nodes lymph node SI
--- BG I 51 --- --- --- ---
--- BG II 24 --- --- --- ---
--- CG 5421 5384 8 672.9
5 TG 1 6985 6948 8 868.4 1.29
10 TG 2 16340 16303 8 2037.8 3.03
25 TG 3 34048 34011 8 4251.3 6.32

EC3 = 9.9%

In vivo (LLNA)

Resultsopen allclose all
Parameter:
SI
Remarks on result:
other: see above
Parameter:
other: disintegrations per minute (DPM)
Remarks on result:
other: see Remark
Remarks:
Test item Group Measurement Calculation Result concentration DPM DPM-BGa number of DPM per SI % (w/v) lymph nodes lymph node --- BG I 88 --- --- --- --- --- BG II 17 --- --- --- --- --- 1 6509 6457 8 807.1 6.25 2 7120 7068 8 883.4 1.09 12.5 3 5815 5763 8 720.3 0.89 25 4 9783 9731 8 1216.3 1.51 BG = Background (1 ml 5% trichloroacetic acid) in duplicate 1 = Control Group 2-4 = Test Group S.I. = Stimulation Index a) = The mean value was taken from the figures BG I and BG II b) = Since the lymph nodes of the animals of a dose group were pooled, DPM/node was determined by dividing the measured value by the number of lymph nodes pooled The EC3 Value could not be calculated, since all SI´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 was not a skin sensitiser under the described conditions.
Executive summary:

In order to study a possible contact allergenic potential of the substance a LLNA test according to OECD 429 was performed. Three groups each of four female mice were treated daily with the test item at concentrations of 6.25, 12.5, and 25% (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 1.09, 0.89, and 1.51 were determined with the test item at concentrations of 6.25, 12.5, and 25% in dimethylsulfoxide. The EC3 value could not be calculated, since none of the tested concentrations induced an S.I. greater than 3.

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