Registration Dossier

Diss Factsheets

Toxicological information

Skin sensitisation

Currently viewing:

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: Current guidelin, 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:
2,2'-(1,4-phenylene)bis[4-[(4-methoxyphenyl)methylene]oxazol-5(4H)-one]
EC Number:
257-055-0
EC Name:
2,2'-(1,4-phenylene)bis[4-[(4-methoxyphenyl)methylene]oxazol-5(4H)-one]
Cas Number:
51202-86-9
Molecular formula:
C28H20N2O6
IUPAC Name:
2,2'-(1,4-phenylene)bis[4-[(4-methoxyphenyl)methylene]oxazol-5(4H)-one]

In vivo test system

Test animals

Species:
mouse
Strain:
CBA
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 (beginning of acclimatisation)
- Weight at study initiation: no data
- Housing: Makrolon Type I, with wire mesh top (EHRET GmbH, D-79302 Emmendingen)
- Diet (e.g. ad libitum): pelleted standard diet, ad libitum
- Water (e.g. ad libitum): tap water, ad libitum,


ENVIRONMENTAL CONDITIONS
temperature 22 + 3°C
relative humidity 30-74%
artificial light 6.00 a.m. - 6.00 p.m.

Study design: in vivo (LLNA)

Vehicle:
acetone/olive oil (4:1 v/v)
Concentration:
6.25, 12.5, and 25% (w/v) in acetone:olive oil (4+1).
No. of animals per dose:
4
Positive control substance(s):
not specified

Results and discussion

In vivo (LLNA)

Results
Parameter:
other: disintegrations per minute (DPM)
Remarks on result:
other: see table below

Any other information on results incl. tables

see table below

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 found to be not a skin sensitiser under the
described conditions.
Executive summary:

In order to study a possible contact allergenic potential of the test item, 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 acetone:olive oil (4+1) 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 (acetone:olive oil (4+1)) 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 (S.I.) of 2.1, 1.8, and 0.7 were determined with the test item at concentrations of 6.25, 12.5, and 25% in acetone:olive oil (4+1), respectively. The EC3 value could not be calculated, since none of the tested concentrations induced an S.I. greater than 3.