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Toxicological information

Skin sensitisation

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Administrative data

Endpoint:
skin sensitisation: in vivo (LLNA)
Type of information:
migrated information: read-across based on grouping of substances (category approach)
Adequacy of study:
key study
Study period:
From 11 OCT 2004 to 10 NOV 2004
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: guideline study (OECD TG 429) GLP compliant

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2005
Report Date:
2005

Materials and methods

Test guideline
Qualifier:
according to
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

Reference
Name:
Unnamed
Type:
Constituent

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, Horst/The Netherlands
- Age at study initiation: 8-12 weeks (beginning of acclimatization)
- Weight at study initiation: mean: 18.7 +/- 1.1 g
- Housing: individually, Makrolon Type I cages
- Diet: pelleted standard diet (Harlan Winkelmann, Borchen/Germany), ad libitum
- Water: tap water, ad libitum
- Acclimatization: yes (acclimatization period not given)


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/-3
- Humidity (%): 30-70%
- Photoperiod (hrs dark / hrs light): 12 hrs/12 hrs


Study design: in vivo (LLNA)

Vehicle:
dimethyl sulphoxide
Concentration:
0%, 2%, 4%, 8% (w/v)
No. of animals per dose:
5 females per dose group
2 females in the pre-test
Details on study design:
RANGE FINDING TESTS:
- non GLP
- Compound solubility: 8% (w/v) suspension in DMSO was the highest technically applicable concentration; higher concentrations could also not be achieved with other vehicles
- Irritation: no swelling was observed at concentrations of 1.0, 2.0, 4.0 and 8.0% (w/v) after a single application
- Systemic toxicity: not observed up to the highest concentration tested
- Lymph node proliferation response: not examined


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


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:
- calculation of mean values and standard deviations for body weight
- Dunnett-test (ANOVA) to test for statistical significance of the results between the test item groups

Results and discussion

Positive control results:
Stimulation indices of 1.96, 3.03 and 4.92 were determined with the positive control substance at concentrations of 5%, 10% and 25% (w/v), respectively, in acetone:olive oil (4+1). An EC3 value of 9.9% (w/v) was calculated.

In vivo (LLNA)

Resultsopen allclose all
Parameter:
SI
Remarks on result:
other: Stimulation indices were all below 3. The following SI were calculated: 2% test item: 1.3 4% test item: 1.2 8% test item: 1.4
Parameter:
other: disintegrations per minute (DPM)
Remarks on result:
other: Background: 3.4 and 0.0 dpm Control group: 631 dpm/lymph node 2% test item: 792 dpm/lymph node 4% test item: 767 dpm/lymph node 8% test item: 894 dpm/lymph node

Any other information on results incl. tables

The animals did not show any clinical signs during the course of the study and no cases of mortality were observed. The body weight of the animals was within the normal range. 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: EU
Conclusions:
The test substance was not sensitising in this LLNA in concentrations up to 8% (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 according to OECD TG 429. The test was performed using test item concentrations of 2, 4 and 8% (w/v). The animals (5 female mice/dose group) 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 1.3, 1.2 and 1.4 were determined with the test item at concentrations of 2, 4 and 8% (w/v) in DMSO, respectively. The results obtained with the positive control confirmed the validity of the test. The test item was not a skin sensitiser under the conditions tested.