β,β-carotene

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 2010-01-26 to 2010-02-16

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP study, according to OECD guideline. The study was performed with a formulation containing 13.1% beta-Carotene.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)

GLP compliance:

yes (incl. QA statement)

Type of study:

mouse local lymph node assay (LLNA)

Test material

Test material information

Constituent 1

Reference substance name:

β,β-carotene

EC Number:

230-636-6

EC Name:

β,β-carotene

Cas Number:

7235-40-7

Molecular formula:

C40H56

IUPAC Name:

β,β-carotene

Details on test material:

- Name of test material (as cited in study report): beta-carotene 10% CWS Star
- Analytical purity: 13.1% beta-Carotene content, dose calculation not adjusted to purity
- Lot/batch No.: UT08070004
- Expiration date of the lot/batch: July 2011
- Storage condition of test material: at +2 - +8 °C, light and moisture protected

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 Laboratories BV, Postbus 6174, 5960 AD Horst / The Netherlands
- Age at study initiation: 8-12 weeks
- Weight at study initiation: 18-22 g
- Housing: single
- Diet (e.g. ad libitum): pelleted standard diet, ad libitum
- Water (e.g. ad libitum): tap water, ad libitum
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22±2
- Humidity (%): 20-65
- Photoperiod (hrs dark / hrs light): 12/12

Study design: in vivo (LLNA)

Vehicle:

other: ethanol:deionised water (3+7)

Concentration:

5, 10, 25%

No. of animals per dose:

4

Details on study design:

RANGE FINDING TESTS:
- Compound solubility: 25% (w/w) suspension in ethanol:deionised water (3+7)
- Irritation: the top dose (25%) is the highest technically achievable concentration whilst avoiding systemic toxicity and excessive local irritation

MAIN STUDY
ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method: LLNA
- Criteria used to consider a positive response:
-exposure to at least one concentration of the test item resulted in an incorporation of 3HTdR at least 3-fold or greater than that recorded in control mice, as indicated by the stimulation index.
-the data are compatible with a conventional dose response, although allowance must be made (especially at high topical concentrations) for either local toxicity or immunological suppression.

TREATMENT PREPARATION AND ADMINISTRATION:

Topical Application
Each test group of mice was treated by topical (epidermal) application to the dorsal surface of each ear (left and right) with different test item concentrations of 5, 10 and 25% (w/w) in ethanol:deionised water (3+7). The application volume, 25 µL, was spread over the entire dorsal surface (Ø ~ 8 mm) of each ear once daily for three consecutive days. A further group of mice was treated with an equivalent volume of the relevant vehicle alone (control animals)

Administration of 3H-Methyl Thymidine (3HTdR)
Five days after the first topical application, all mice received a single dose of 250 µL of 80.9 µCi/mL 3HTdR (corresponds to 20.2 µCi 3HTdR per mouse) by intravenous injection via a tail vein.

Positive control substance(s):

hexyl cinnamic aldehyde (CAS No 101-86-0)

Statistics:

The mean values and standard deviations of the body weight were calculated.

Results and discussion

Positive control results:

A GLP-conform study with the positive reference substance revealed the sensitivity and suitability of the test system.

In vivo (LLNA)

Results

Results 1

Parameter:

SI

Value:

1.52

Test group / Remarks:

5%

Results 2

Parameter:

SI

Value:

1.37

Test group / Remarks:

10 %

Results 3

Parameter:

SI

Value:

1.5

Test group / Remarks:

25 %

Results 4

Parameter:

other: disintegrations per minute (DPM)

Remarks on result:

other: 5 %: 359.8 10 %: 324.2 25 %: 355.4

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Conclusions:

The test item beta-Carotene 10 % CWS Star was not a skin sensitiser under the described conditions.

Executive summary:

In a GLP and the OECD guideline 429 conform study, the test item beta-Carotene 10 % CWS Star suspended in ethanol:deionised water (3:7) was assessed for its possible contact allergenic potential. For this purpose a local lymph node assay was performed using test item concentrations of 5, 10 and 25 % (w/w). The animals did not show any clinical signs during the course of the study and no cases of mortality were observed. In this study, Stimulation Indices (SI) of 1.52, 1.37 and 1.50 were calculated for the groups treated with the test item at concentrations of 5, 10 and 25 % in ethanol:deionised water (3:7), respectively. The test item beta-carotene 10 % CWS Star was not a skin sensitiser in this assay.