Ethyl 3,5,5-trimethylhexanoate

Specific investigations: other studies

Administrative data

Endpoint:

phototoxicity

Type of information:

experimental study

Adequacy of study:

key study

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:

1983

Report date:

1983

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

Ch. Gloxhuber, J. Soc. Cosmet. Chem., 27, 399 (1976)

GLP compliance:

no

Remarks:

study performed before implementation of GLP)

Type of method:

in vivo

Endpoint addressed:

skin irritation / corrosion

Test material

Test material information

Constituent 1

Reference substance name:

Ethyl 3,5,5-trimethylhexanoate

EC Number:

266-959-4

EC Name:

Ethyl 3,5,5-trimethylhexanoate

Cas Number:

67707-75-9

Molecular formula:

C11H22O2

IUPAC Name:

ethyl 3,5,5-trimethylhexanoate

Test material form:

other: 5% solution in ethanol

Details on test material:

- Name of test material (as cited in study report): 3,5,5-Trimethyl-ethyl-capronat

Test animals

Species:

mouse

Strain:

other: hairless (hr hr)

Sex:

male

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: own breeding
- Age at study initiation: adult
- Weight at study initiation: 25 – 28 g
- Fasting period before study: no
- Housing: individually in type 1 makrolon cages
- Diet (e.g. ad libitum): Altromin maintainance diet 1314, ad libitum
- Water (e.g. ad libitum): tap water, ad libitum
- Acclimation period: no data

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 1
- Humidity (%): approx. 50
- Air changes (per hr): 11
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:

dermal

Vehicle:

ethanol

Details on exposure:

TEST SITE
- Area of exposure: back, 2 x 1.5 cm

REMOVAL OF TEST SUBSTANCE
- Washing (if done): no

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 2 drops per application
- Concentration (if solution): 5%

Analytical verification of doses or concentrations:

no

Duration of treatment / exposure:

1 h

Frequency of treatment:

2 applications: 1 h + directly before irradiation

Post exposure period:

6 d

Doses / concentrations

Remarks:

Doses / Concentrations:
0, 5%
Basis:
nominal conc.

No. of animals per sex per dose:

10 (test group, irradiation control, vehicle control), 5 (only vehicle / test substance without irradiation)

Control animals:

other: irradiation control (no test substance, only irradiation) + test substance control (only test substance, no irradiation) + vehicle control (vehicle ± irradiation)

Examinations

Positive control:

Xanthotoxin

Results and discussion

Details on results:

No significant difference between the increase of skinfold thickness of animals treated with test substance + irradiation compared to the irradiation control (no test substance, only irradiation) was observed. The animals treated with test substance without irradiation showed no significant difference in the increase of skinfold thickness compared to the untreated control group.
The positive control substance Xanthotoxin caused a clear positive response after irradiation.

Applicant's summary and conclusion

Conclusions:

3,5,5-Trimethyl-ethyl capronate (5% in ethanol) was not phototoxic to hairless mice in this test.

Executive summary:

In a phototoxicity study according to the method of Gloxhuber (Ch. Gloxhuber, J. Soc. Cosmet. Chem., 27, 399 (1976)), 3,5,5-Trimethyl-ethyl capronate (5% in ethanol) was applied to 2x1.5 cm on the back of 10 hairless mice in 2 applications (1 h + directly before irradiation; 2 drops per application) and irradiated with UV light for 3 min.

Xanthotoxin (1% in ethanol, ± irradiation) was used as positive control.

Animals treated with no test substance, only irradiation served as irradiation control; animals treated with only test substance, no irradiation served as test substance control. Animals treated with Ethanol (± irradiation) served as vehicle control.

Skinfold thickness (edema) was measured after 0, 1, 2, 3, 24, 30, 48, 54, 72, 78 and 144 h.

A substance is considered to be phototoxic when animals treated with the test substance + irradiation (=test group) show an increase in skinfold thickness and both control groups do not develop edema.

No significant difference between the increase of skinfold thickness of animals treated with test substance + irradiation compared to the irradiation control (no test substance, only irradiation) was observed. The animals treated with test substance without irradiation showed no significant difference in the increase of skinfold thickness compared to the untreated control group.

The positive control substance Xanthotoxin caused a clear positive response after irradiation.

3,5,5-Trimethyl-ethyl capronate (5% in ethanol) was not phototoxic to hairless mice in this test.