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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:
July 16 to July 28 2008
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2008
Report Date:
2009

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)
GLP compliance:
yes (incl. certificate)
Type of study:
mouse local lymph node assay (LLNA)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
liquid
Details on test material:
Reaction mass of 3-(2,3-dihydroxypropoxy)-2-hydroxypropyl decanoate and 1-(2,3-dihydroxypropoxy)-3-hydroxypropan-2-yl decanoate
Specific details on test material used for the study:
SOURCE OF TEST MATERIAL
- Source: From sponsor; CIBA Inc.
- Batch No.of test material: 512051
- Expiration date of the lot/batch: December 2008
- Purity test date: certificate of analysis dated June 16, 2008
- pH: 7.15
- Colour: colourless
- Form: liquid

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Room temperature

The test item was considered as 100% for the study

In vivo test system

Test animals

Species:
mouse
Strain:
CBA:J
Sex:
female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Elevage Janvier (F-53941 Le Genest Saint Isle)
- Females (if applicable) nulliparous and non-pregnant: yes
- Age at study initiation: 8 weeks
- Weight at study initiation: 20-22 g
- Housing: The animals were individually housed in suspended solid floor polyprpylene cages furnished with softwood woodflakes
- Diet: ad libitum
- Water:ad libitum
- Acclimation period: a minimum of 5 days
- Indication of any skin lesions:

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19-25
- Humidity (%): 30-70
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12/12

Study design: in vivo (LLNA)

Vehicle:
acetone/olive oil (4:1 v/v)
Concentration:
undiluted, 50 or 25%
No. of animals per dose:
4
Details on study design:
PRE-SCREEN TESTS:

A preliminary screening was performed in one mouse:
Daily treatment with 25 ul undiluted test item, on dorsal surface of ear for 3 days
Observations on days: 1, 2, 3, 4 , 5 and 6
No signs of systemic toxicity were noted.
Dose levels were selected based on this

MAIN STUDY

ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method: Local Lymph node assay
- Criteria used to consider a positive response:
Local reactions:
Increase in ear thickness:
<10% Non-irritant
10-30% slightly irritant
>30% Irritant

Stimulation index (SI) determination:
The proliferation response of lymph node cells was expressed as the numbver of lymphocytes per lymph node and as the ration of lymphocytes into lymph node cells of test nodes relative to that recorded for the control nodes (SI)

When usingt the pooled approach, the SI was calculated according to the following formula:

SI = cell count of treated group / cell count of control group

The test item will be regarded as a sensitiser if at least one concentration of the test item results is greater that 1.4 compared to control values (SI > 1.4)

TREATMENT PREPARATION AND ADMINISTRATION:
The mice were treated daily by application of 25 ul of the appropriate cincentration of test item (0, 25, 50 or 100%) on the dorsal surface of the ear for three consecutive days.
The test item formulation was administered using an automatic micropipette and sprea over the odrsal surface of the ear using the tip of the pipette.

Results and discussion

In vivo (LLNA)

Resultsopen allclose all
Key result
Parameter:
SI
Value:
1.73
Test group / Remarks:
25% test item
Remarks on result:
other:
Remarks:
calculated by pooled approach
Key result
Parameter:
SI
Value:
2.76
Test group / Remarks:
50% test item
Remarks on result:
other:
Remarks:
calculated by pooled approach
Key result
Parameter:
SI
Value:
3.17
Test group / Remarks:
100% test item
Remarks on result:
other:
Remarks:
calculated by pooled approach
Cellular proliferation data / Observations:
DETAILS ON STIMULATION INDEX CALCULATION
A stimulation index more than 1.4 was recorded for all three concentrations (25, 50 and 100%)

CLINICAL OBSERVATIONS:
No mortality and no signs of systemic toxicity were noted in the test and control animals during the test

BODY WEIGHTS
Bodyweight changes of the test animals between day 1 and day 6 were comparable to those observed in the control animals

Any other information on results incl. tables

A slight dryness was registred at D6 in thre treated groups at 50% and 100%.

A moderate to important increase in ear thickness (+16.5%, +29.4%, +41.7%) and in ear weight (+18%, +42.5%, +19.5%) was recorded respectively at the concentrations of 25%, 50% and 100%. The test item must therefore be considered as slightly irritant at 25% and 50% and irritant at 100%.

Applicant's summary and conclusion

Interpretation of results:
Category 1 (skin sensitising) based on GHS criteria
Conclusions:
In view of these results, under these experimental conditions, the itest item, Dermosoft DGMC.., must be classified in category 1B "skin sensitisation" according to the Globally Harmonized System (COM (2007)355 final). The signal word "warning" and the hazard statement H317 "may cause an allergic reaction" are required.
Accoridng to tests on the ear thickness after exposure, the test item must also be considered as slightly irritant at 25% and 50% and irritant at 100%.
Executive summary:

The test was performed to access the skin sensitisation potential of the test item, Dermosoft DGCM.., in the CBA/J mouse strain following topical applications to the dorsal surface of the ear. The test was performed according to OECD guideline 429.

Three groups of each four animals, were treated for three consecutive days with 50 ul (25 ul per ear) with the undilited test item and the test item as a solution in acetone(olive oil (4:1) at concentrations of 25% and 50% (v/v). A further group of four animals was treated with acetone/olive oil (4:1) alone.

No mortality and no signs of systemic toxicity were noted in the test and the control animals during the test.

A slight dryness was registred at D6 in thre treated groups at 50% and 100%. A moderate to important increase in ear thickness (+16.5%, +29.4%, +41.7%) and in ear weight (+18%, +42.5%, +19.5%) was recorded respectively at the concentrations of 25%, 50% and 100%. The test item must therefore be considered as slightly irritant at 25% and 50% and irritant at 100%.

The SI calculated by pooled approach was 1.71, 2.76 and 3.17, for the treated groups at 25%, 50% and 100%, respectively.

In view of these results, under these experimental conditions, the itest item, Dermosoft DGMC.., must be classified in category 1B "skin sensitisation" according to the Globally Harmonized System (COM (2007)355 final). The signal word "warning" and the hazard statement H317 "may cause an allergic reaction" are required.