Octadecanoic acid, reaction products with diethylenetriamine and urea, acetates

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

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

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.42 (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

Constituent 1

Test material form:

other: waxy solid

Details on test material:

None

Specific details on test material used for the study:

Sponsor's identification: FAT 93580/A
Description: extremely pale yellow waxy solid
Batch number: 0022357000
Purity:94.3%
Date received: 23 January 2013
Expiry Date: 15 December 2015
Storage conditions: room temperature in the dark

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: 8-12 weeks old
- Weight at study initiation: 15 - 23 g
- Housing: individually in suspended solid-floor polypropylene cages
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19-25
- Humidity (%): 30-70
- Air changes (per hr): 15
- Photoperiod (hrs dark/hrs light): 12/12

Study design: in vivo (LLNA)

Vehicle:

propylene glycol

Concentration:

2.5, 5 or 10 % w/w in propylene glycol

No. of animals per dose:

4

Details on study design:

PRE-SCREEN TESTS:
- Compound solubility: 25 µI of the test item at a concentration of 10% w/w in propylene glycol
- Irritation: None
- Ear thickness measurements: Post dosing day 1, day 3 and day 6.
- Erythema scores: Daily

MAIN STUDY
ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method: Estimation of the Proliferative Response of Lymph Node Cells
- Criteria used to consider a positive response: The test item 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 item 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 propylene glycol. 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 item to the dorsal surface of each ear for three consecutive days (Days 1, 2, 3). The test item 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. Five days following the first topical application of the test item or vehicle (Day 6) all mice were injected via the tail vein with 250 μL of phosphate buffered saline (PBS) containing 3H-methyl thymidine (³HTdR: 80 μCi/mL, specific activity 2.0 Ci/mmol, ARC UK Ltd) giving a total of 20 μCi to each mouse.

Positive control substance(s):

other: Phenylacetaldehyde (>90 %)

Statistics:

None

Results and discussion

Positive control results:

Test Item: Phenylacetaldehyde (>90 %)
Stimulation Index: 6.32
Result: Positive
Conclusion. Phenylacetaldehyde (>90 %) was considered to be a sensitizer under the conditions of the test.

In vivo (LLNA)

Results

Results 1

Parameter:

SI

Value:

1.37

Test group / Remarks:

2.5%

Results 2

Parameter:

SI

Value:

1.27

Test group / Remarks:

5 %

Results 3

Parameter:

SI

Value:

1.71

Test group / Remarks:

10 %

Cellular proliferation data / Observations:

CLINICAL OBSERVATION:
There were no deaths. No signs of systemic toxicity were noted in the test or control animals during the test.
Bodyweight changes of the test animals between Day 1 and Day 6 were comparable to those observed in the corresponding control group animals over the same period.

No irritation was observed at the maximal concentration tested (10 %).

Any other information on results incl. tables

Table 1. Disintegrations per Minute, Disintegrations per Minute/Node and Stimulation Index

Concentration (% w/w) in propylene glycol	dpm	Dpm/Node^a	Stimulation Index^b	Result
Vehicle	4607.43	575.93	na	na
2.5	6301.03	787.63	1.37	negative
5	5861.93	732.74	1.27	negative
10	7891.20	986.40	1.71	negative

a: disintegrations per minute/node obtained by dividing the disintegrations per minute value by 8 (total number of lymph nodes)

b: stimulation index of 3.0 or greater indicates a positive result

na = not applicable

Positive control : Phenylacetaldehyde (90 %)

Concentration (% v/v) in propylene glycol	Stimulation Index	Result
2.5	6.32	Positive

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

According to OECD TG 429 and EU Method B.42, the test item FAT #: 93580/A was considered to be a non-sensitizer.

Executive summary:

A study was performed to assess the skin sensitisation potential of the test item FAT 93580/A in the CBA/Ca strain mouse following topical application to the dorsal surface of the ear according to OECD TG 429 and Method B42 (EC) and as per GLP.

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 suspension in propylene glycol at concentrations of 2.5, 5 or 10 % w/w. A further group of four animals was treated with propylene glycol alone.

The Stimulation Index (SI) expressed as the mean radioactive incorporation for each treatment group divided by the mean radioactive incorporation of the vehicle control group are as follows:

Concentration (% w/w) in propylene glycol	Stimulation Index	Result
2.5	1.37	negative
5	1.27	negative
10	1.71	negative

Based on the findings, the test item FAT #: 93580/A was considered to be a non-sensitizer.