N-octyldecyloctadecanamide

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From May to June 2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2013

Report date:

2013

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of study:

mouse local lymph node assay (LLNA)

Test material

Test material information

1

Reference substance name:

N-octyldecyloctadecanamide

EC Number:

955-212-4

Cas Number:

13276-08-9

Molecular formula:

Variable

IUPAC Name:

N-octyldecyloctadecanamide

Test material form:

solid

Details on test material:

- Chemical registery number : 236-276-6
- Chemical name: N-octadecylstearamide

Based on the qualitative and quantitative information on the composition, the sample used are representative of the boundary composition shared and agreed by each registrant.

In vivo test system

Test animals

Species:

mouse

Strain:

CBA

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Harlan Laboratories UK Ltd., Oxon, UK.
- Age at study initiation: eight to twelve weeks old
- Weight at study initiation: 15 to 23 g
- Housing: The animals were individually housed in suspended solid floor polypropylene cages furnished with softwood woodflakes.
- Diet (e.g. ad libitum): Free access to mains food was allowed throughout the study.
- Water (e.g. ad libitum): Free access to mains tap water was allowed throughout the study.
- Acclimation period: at least five days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19 to 25°C
- Humidity (%): 30 to 70%
- Air changes (per hr): approximately fifteen changes per hour
- Photoperiod (hrs dark / hrs light): twelve hours continuous light (06.00 to 18.00) and twelve hours darkness

Study design: in vivo (LLNA)

Vehicle:

acetone/olive oil (4:1 v/v)

Concentration:

Preliminary Screening Test: 10% w/w
Main Test: 10%, 5% or 2.5% w/w

No. of animals per dose:

Preliminary Screening Test: one mouse
Main Test: four mice

Details on study design:

RANGE FINDING TESTS:
Irritation: No signs of systemic toxicity, visual local skin irritation or irritation indicated by an equal to or greater than 25% increase in mean ear thickness were noted.
TREATMENT PREPARATION AND ADMINISTRATION:

- Name of test method:
- Criteria used to consider a positive response: The test material will be regarded as a sensitizer if at least one concentration of the test item results in a threefold or greater increase in 3HTdR incorporation compared to control values. Any test material failing to produce a threefold or greater increase in 3HTdR incorporation will be classified as a "non-sensitizer."

TREATMENT PREPARATION AND ADMINISTRATION:
Groups of four mice were treated with the test item at concentrations of 10%, 5% or 2.5% w/w in acetone/olive oil 4:1. The preliminary screening test suggested that the test item would not produce systemic toxicity or excessive local skin irritation at the highest suitable concentration. The mice were treated by daily application of 25 µL of the appropriate concentration of the test material to the dorsal surface of each ear for three consecutive days (Days 1, 2, 3). The test material formulation was administered using an automatic micropipette and spread over the dorsal surface of the ear using the tip of the pipette.
A further group of four mice received the vehicle alone in the same manner.

Positive control substance(s):

other: a-Hexylcinnamaldehyde, tech., 85%

Results and discussion

Positive control results:

The Stimulation Index expressed as the mean radioactive incorporation for the treatment group divided by the mean radioactive incorporation of the vehicle control group is 7.33.
a-Hexylcinnamaldehyde, tech., 85% was considered to be a sensitizer under the conditions of the test.

In vivo (LLNA)

Results

Results 1

Parameter:

SI

Value:

1.89

Test group / Remarks:

2.5%

Results 2

Parameter:

SI

Value:

1.36

Test group / Remarks:

5%

Results 3

Parameter:

SI

Value:

1.16

Test group / Remarks:

10%

Any other information on results incl. tables

There were no deaths. No signs of systemic toxicity were noted in the test or control animals during the test.

Body weight change of the test animals between Day 1 and Day 6 was comparable to those observed in the corresponding control group animals over the same period.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The test material was considered to be a non-sensitizer under the conditions of the test.

Executive summary:

A study was performed to assess the skin sensitization potential of the test item in the CBA/Ca strain mouse following topical application to the dorsal surface of the ear.

Following a preliminary screening test in which no clinical signs of toxicity were noted at a concentration of 10% w/w, this concentration was selected as the highest dose investigated in the main test of the Local Lymph Node Assay. Three groups, each of four animals, were treated with 50 μL (25 μL per ear) of the test item as a solution in acetone/olive oil 4: 1 at concentrations of 10%, 5% or 2.5% w/w. A further group of four animals was treated with acetone/olive oil 4:1 alone.

The Stimulation Index expressed as the mean radioactive incorporation for each treatment group divided by the mean radioactive incorporation of the vehicle control group was comprised between 1.16 and 1.89.

The test item was considered to be a non-sensitizer under the conditions of the test.