4-tert-butyl-2-(5-tert-butyl-2-oxo-2,3-dihydro-1-benzofuran-3-yl)phenyl 3,5-di-tert-butyl-4-hydroxybenzoate

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2012

Report date:

2012

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

adopted 22 July 2010

Deviations:

not specified

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.42 (Skin Sensitisation: Local Lymph Node Assay)

Version / remarks:

dated 30 May 2008

Deviations:

not specified

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:

4-tert-butyl-2-(5-tert-butyl-2-oxo-2,3-dihydro-1-benzofuran-3-yl)phenyl 3,5-di-tert-butyl-4-hydroxybenzoate

EC Number:

700-641-2

Cas Number:

1261240-30-5

Molecular formula:

C37H46O5

IUPAC Name:

4-tert-butyl-2-(5-tert-butyl-2-oxo-2,3-dihydro-1-benzofuran-3-yl)phenyl 3,5-di-tert-butyl-4-hydroxybenzoate

Test material form:

other: Crystalline powder

Details on test material:

Batch No.: S25211001
Purity: 99.15%
Stability in solvent: Not indicated
Storage: at room temperature, light protected.

In vivo test system

Test animals

Species:

mouse

Strain:

other: CBA/CaOIaHsd

Sex:

female

Details on test animals and environmental conditions:

(1) Details on test animals:
Number of animals for the pre-test: 2 females
Number of animals for the main study: 16 females
Number of animals per group 4 females (nulliparous and non-pregnant)
Number of test groups: 3
Number of control (vehicle) groups: 1
Age: Pre-test: 11-12 weeks (beginning of treatment); main study: 9-10 weeks (beginning of treatment)
Identifcation: The animals were distributed into the test groups at random. All animals belonging to the same experimental group were kept in one cage. In the main experiment, the animals were identified by tail tags. In the pre-experiment, animals were identified by cage number.
Acclimatisation: At least 5 days prior to the start of dosing under test conditions after health examination. Only animals without any visible signs of illness were used for the study.
(2) Details on environmental conditions
Housing: group
Cage type: Makrolon Type II (pre-test) / III (main study), with wire mesh top
Bedding: granulated soft wood bedding
Feed: pelleted standard diet, ad libitum
Water: tap water, ad libitum
Environment: Temperature: 22+/-2 degree C; Relative humidity: 30-65% (acclimation period), 45-65% (main study); Artificial light 6.00 a.m. - 6.00 p.m.

Study design: in vivo (LLNA)

Vehicle:

dimethylformamide

Concentration:

10, 25, 50% (w/v)

No. of animals per dose:

4

Details on study design:

Each test group of mice was treated by topical (epidermal) application to the dorsal surface of each ear with test item concentrations of 10, 25, and 50% (w/v) in dimethylformamide. The application volume, 25 VL/ear/day, was spread over the entire dorsal surface ( Φ - 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).

Positive control substance(s):

other: α-Hexylcinnamaldehyde

Statistics:

The mean values and standard deviations were calculated in the body weight tables. However, both biological and statistical significance were considered together.

Results and discussion

Positive control results:

Test item concentration % (w/v) Group Measurement DPM DPM-BG No. of lymph nodes DPM per lymph node S.I. Result
- BGI 15 - - - -
- BGII 22 - - - -
0 1 3814 3796 8 474.4 1.00
5 2 6461 6443 8 805.3 1.70
10 3 6878 6860 8 857.4 1.81
25 4 22393 22375 8 2796.8 5.90
Vehicle: acetone: olive oil (4+1 v/v)
BG=Background (1 mL 5% trichloroacetic acid) in duplicate
1= Control Group
2-4= Test Group
S.I. = Stimulation Index
DPM-BG= The mean value was taken from the figures BGI and BGII
DPM per lymph node= since the lymph nodes of the animals of a dose group were pooled, DPM/node was determined by dividing the measured value by the number of lymph nodes pooled.
Calculation of the EC3 value (EC3=Estimated concentration for a S.I. of 3) = 14.4% (w/v)

In vivo (LLNA)

Results

Results 1

Key result

Parameter:

SI

Value:

1.04

Variability:

no data

Test group / Remarks:

Test item concentration: 10% (w/v)
Number of animal per group: 4 females (nulliparous and non-pregnant)

Results 2

Key result

Parameter:

SI

Value:

1.07

Variability:

no data

Test group / Remarks:

Test item concentration 25% (w/v);
Number of animal per group: 4 females (nulliparous and non-pregnant)

Results 3

Key result

Parameter:

SI

Value:

0.95

Variability:

no data

Test group / Remarks:

Test item concentration: 50% (w/v)
Number of animal per group: 4 females (nulliparous and non-pregnant)

Any other information on results incl. tables

Viability/Mortality: No deaths occurred during the study period.

Clinical Signs: No systemic findings were observed during the study period. On day 4 to 6, the animals treated with a test item concentration of 10 and 25% showed an erythema of the ear skin (Score 1). Animals treated with 50% test item concentration showed an erythema of the ear skin (Score 1) on day 4 and 6 and Score 2 on day 5.

Body Weights: The body weight of the animals, recorded prior to the first application and prior to treatment with 3HTdR, was within the range commonly recorded for animals of this strain and age.

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Criteria used for interpretation of results: EU

Conclusions:

The test substance was not a skin sensitiser under the test condition of this study.