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Toxicological information

Skin sensitisation

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Administrative data

Endpoint:
skin sensitisation: in vivo (LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Study period:
April 03 - 17, 2013
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2013
Report Date:
2013

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)
Version / remarks:
July 22, 2010
Deviations:
no
Qualifier:
according to
Guideline:
EU Method B.42 (Skin Sensitisation: Local Lymph Node Assay)
Version / remarks:
May 30, 2008
Deviations:
no
GLP compliance:
yes (incl. certificate)
Type of study:
mouse local lymph node assay (LLNA)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: bulk

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
- Age at study initiation: Pre-test: 10-11 weeks; Main test: 8 - 9 weeks
- Weight at study initiation: Pre-test: 21.3 g; Main test: 20.8+/- 1.5 g
- Housing: grouped per dose
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 + 2°C
- Humidity (%): 45-65%
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: day 1 To: day 6

Study design: in vivo (LLNA)

Vehicle:
dimethylformamide
Concentration:
10, 25, and 50 % (w/w)
No. of animals per dose:
5
Details on study design:
RANGE FINDING TESTS:
- Compound solubility: 50% in DMF
- Irritation: No
- Lymph node proliferation response: -

MAIN STUDY
ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method: OECD 429
- Criteria used to consider a positive response: Stimulation index > 3

TREATMENT PREPARATION AND ADMINISTRATION:
The test item was placed into an appropriate container on a tared balance and DMF was added. The different test item concentrations were prepared individually. The preparations were made freshly before each dosing occasion.
Each test group of mice was treated by (epidermal) topical application to the dorsal surface of each ear with test item concentrations of 10, 25, and 50% (w/w) in DMF. The application volume, 25 μL/ear/day, was spread over the entire dorsal surface of each ear once daily for three consecutive days.
Positive control substance(s):
hexyl cinnamic aldehyde (CAS No 101-86-0)
Statistics:
Standard statistical methods have been applied for data processing.

Results and discussion

Positive control results:
Conc. SI
0%: 1.0
5% 1.5
10% 1.9
25% 5.7

In vivo (LLNA)

Resultsopen allclose all
Key result
Parameter:
SI
Value:
1
Test group / Remarks:
Vehicle group
Key result
Parameter:
SI
Value:
1.1
Test group / Remarks:
Test group (10%)
Key result
Parameter:
SI
Value:
1.7
Test group / Remarks:
Test group (25%)
Key result
Parameter:
SI
Value:
2.1
Test group / Remarks:
Test group (50%)
Cellular proliferation data / Observations:
CELLULAR PROLIFERATION DATA
Test item concentration Mean DPM per animal (2 lymph nodes) SD
Vehicle 375.4 126.9
10% 417.6 225.2
25% 621.2 239.9
50% 789.8 395.5

DETAILS ON STIMULATION INDEX CALCULATION

EC3 CALCULATION : The EC3 value could not be calculated, since all S.I.´s are below the threshold value of 3.

CLINICAL OBSERVATIONS: No deaths occurred during the study period. No symptoms of local skin irritation at the ears of the animals and no signs of systemic toxicity were observed during the study period.

BODY WEIGHTS: The body weight of the animals was within the range commonly recorded for animals of this strain and age.

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
Conclusions:
The test item was not a skin sensitiser under the test conditions of this study.
Executive summary:

In the study the test item formulated in DMF was assessed for its possible skin sensitising potential. The GLP study was performed according to OECD TG 429.
For this purpose a local lymph node assay was performed using test item concentrations of 10, 25, and 50% (w/w). The highest concentration tested was the highest concentration that could be achieved whilst avoiding systemic toxicity and excessive local skin irritation as confirmed by a pre-experiment.
The animals did not show any signs of systemic toxicity or local skin irritation during the course of the study and no cases of mortality were observed. Neither for the vehicle treated animals nor for the test item treated groups, a relevant increase in ear thickness values was observed over the course of the study.
In this study Stimulation Indices (S.I.) of 1.1, 1.7, and 2.1 were determined with the test item at concentrations of 10, 25, and 50% (w/w) in DMF, respectively. The EC3 value could not be calculated, since all S.I.´s are below the threshold value of 3.

The test item was not a skin sensitiser under the test conditions of this study.