Isooctadecyl isooctadecanoate

Specific investigations: other studies

Administrative data

Endpoint:

phototoxicity

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

23 - 24 Jan 1989

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Acceptable, well documented study report which meets basic scientific principles.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1989

Materials and methods

Principles of method if other than guideline:

Evaluation of skin reactions after dermal application of the test substance which was subsequently exposed to UV radiations (UVA + UVB).

GLP compliance:

yes

Type of method:

in vivo

Endpoint addressed:

not applicable

Test material

Test material information

Constituent 1

Reference substance name:

Isooctadecyl isooctadecanoate

EC Number:

255-485-3

EC Name:

Isooctadecyl isooctadecanoate

Cas Number:

41669-30-1

Molecular formula:

C36H72O2

IUPAC Name:

2-methylheptadecyl 3-methylheptadecanoate

Details on test material:

- Name of test material (as cited in study report): [only trade name given]
- Physical state: thick liquid
- Analytical purity: no data

Test animals

Species:

guinea pig

Strain:

Hartley

Sex:

not specified

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Maury, Villefranche de Lonchat
- Weight at study initiation: about 300 g
- Housing: The animals were kept in groups of 3 in Makrolon boxes (46.5 x 31 x 19 cm), the floor of which was covered with clean saw dust. A guinea pig feeding device and a drinking bottle were fixed to the stainless steel wired lid.
- Diet: UAR 106, ad libitum
- Water: tap water, ad libitum
- Acclimation period: at least one week

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21 ± 2
- Humidity (%): 55 ± 10
- Air changes (per hr): 14
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:

dermal

Vehicle:

unchanged (no vehicle)

Details on exposure:

TEST SITE
- Area of exposure: 1 cm²
- Time intervals for shavings or clipplings: at least 72 h prior to application of the test material

TEST MATERIAL
- Amount applied: 0.02 mL

USE OF RESTRAINERS FOR PREVENTING INGESTION: no

Analytical verification of doses or concentrations:

no

Duration of treatment / exposure:

30 min prior to UV irradiation
1603 s UVA irradiation
58 s UVB irradiation

Frequency of treatment:

single application without washing

Post exposure period:

24 h

Doses / concentrations

Remarks:

Doses / Concentrations:
0.02 mL/cm²
Basis:
other: actual amount applied

No. of animals per sex per dose:

10

Control animals:

other: only UVA and UVB irradiated sites of the same animal served as control

Details on study design:

PREPARATION OF THE ANIMALS

Prior to the application of the test material and UV irradiation, animals were slightly anaesthetised with Ketamine (0.1 g/kg bw of chlroketam Vétoquinol) for immobilisation, and the clipped skin was hot wax depilated.

IRRADIATION SOURCES

Irradiations were performed using Philips tubes:

- TL 20W/09 N for UVA irradiations
- TL 20W/12 UV for UVB irradiations

Radiation levels were measured with a UVx Wilber Lourmat radiometer.

The exposure times chosen corresponded to radiation doses (in mW/cm²) of UV (A+B) which allowed working at suberythematous levels:

- 1603 s for irradiations with TL 20W/09 N tubes, corresponding to 3302.18 mJ/cm² UVA energy and 224.42 mJ/cm² UVB energy.
- 58 s for irradiations with TL 20W/12 UV tubes, corresponding to 17.4 mJ/cm² UVA energy and 62.64 mJ/cm² UVB energy.

TREATMENTS

The clipped and depilated area (back and flanks) was divided in 6 areas of 1 cm² (3 on both sides of the vertebral axis).

Area 1: Test material + UVA
Area 2: Test material + UVB
Area 3: Test material
Area 4: Positive control (8-metoxypsoralene + UVA
Area 5: UVA
Area 6: UVB

Examinations

Examinations:

EVALUATION OF SKIN REACTIONS

Animals were observed for skin reactions 24 h post-treatment. The degree of induced erythema and/or edema was evaluated according to the Draize scoring system for skin irritation.

For each of the 6 areas the mean score was calculated.

INTERPRETATION OF RESULTS

The test material was considered as phototoxic if the average of the scores obtained with the test substance, after UVA or UVB irradiation, was significantly higher that that of the corresponding control areas, which were only UVA or UVB irradiated.

Positive control:

8-metoxypsoralene + UVA

Results and discussion

Details on results:

No significant skin reactions was observed on the sites treated with the test material, whether exposed to UV radiation or not.
Under the same conditions, the sites treated with the positive control 8-MOP showed major reactions.
The test substance, therefore, devoid of phototoxic effects under the experimental conditions adopted.

Applicant's summary and conclusion

Conclusions:

Not phototoxic