Fatty acids, C18-unsatd., dimers, compds. with coco alkylamines

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:

other: GLP 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 442B (Skin Sensitization: Local Lymph Node Assay: BrdU-ELISA)

Version / remarks:

adopted July 2010

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

adopted May 2008

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.2600 (Skin Sensitisation)

Version / remarks:

adopted March 2003

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:

Fatty acids, C18-unsatd., dimers, compds. with coco alkylamines

EC Number:

614-682-8

Cas Number:

68647-95-0

Molecular formula:

Not applicable (UVCB substance)

IUPAC Name:

Fatty acids, C18-unsatd., dimers, compds. with coco alkylamines

Details on test material:

- Name of test material (as cited in study report): Fatty acids, C18-unsatd., dimers, compds. with coco alkylamines
- Physical state: amber liquid
- Analytical purity: The test item is a complex mixture of isomers and homologue components, so no purity can be stated (For details see analytical report BASF study-No.: 11S05363)
- Purity test date: 2012-08-08
- Lot/batch No.: BI514173
- Expiration date of the lot/batch: 2013-04-18
- Stability under test conditions: stable at least for the maximum time of administration
- Storage condition of test material: room temperature

In vivo test system

Test animals

Species:

mouse

Strain:

other: CBA/CaOlaHsd

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Harlan Winkelmann GmbH, Borchen, Germany
- Age at study initiation: main test: 8 weeks; pretest: 9-12 weeks
- Weight at study initiation: 19.6 - 20.5g
- Housing: single in Makrolon type II cages
- Diet (e.g. ad libitum): Stanrab (P) SQC, SDS Special Diets Services, ad lib.
- Water (e.g. ad libitum): tab water ad lib.
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/- 3°C
- Humidity (%): 30-70%
- Air changes (per hr): app. 10
- Photoperiod (hrs dark / hrs light): 12h/12h

Study design: in vivo (LLNA)

Vehicle:

propylene glycol

Concentration:

1%, 2%, 5%

No. of animals per dose:

2 (pre study)
5 (main study)

Details on study design:

RANGE FINDING TESTS: 3 pre-tests were performed in 6 animals per test (2/concentration) to determine the highest non irritant concentration. Mice were treated with 100%, 50%, 25%, 10%, 5%, and 2.5% (w/w) on three consecutive days.
- Irritation: at 10% and above, mice showed local irritation confirmed by increased ear weights >25%. In addition, concentrations above 25% also led to ear swelling > 25%. Body weight loss >5% was observed at 50% and 100%. Groups treated with 2.5% and 5% showed no relevant increase in ear weights or eir swelling nor weight loss. Thus 5% was used as the top concentration.

MAIN STUDY
ANIMAL ASSIGNMENT AND TREATMENT
- 25µL of test substance were spread over the entire dorsal surface of each ear for three consecutive days
- 4 days after the first administration, 5mg BrdU were i.p. injected per mouse.
- mice were sacrificed after 24h and BrdU incorporation measured using a commercial cell proliferation assay kit (Roche, Mannheim)

- Criteria used to consider a positive response:
At least one concentration of the test item resulted in an incorporation of BrdU at least 1.6-fold or greater than that recorded in control mice, as indicated by the Stimulation Index.
Data are compatible with a conventional dose response, although allowance must be made (especially at high topical concentrations) for either local
toxicity or immunological suppression.
An increase in ear weight exceeding the threshold value of 25% was considered to be indicative for excessive local skin irritation.
For BALB/c mice, a cutoff-value for the lymph node cell count index of 1.55 was reported for a positive response.


TREATMENT PREPARATION AND ADMINISTRATION: For better handling, the test item was heated at 60°C for 1h (preparations were heated for 20min). Preparations were produced daily on a weight per weight basis and administered lukewarm.

Positive control substance(s):

hexyl cinnamic aldehyde (CAS No 101-86-0)

Statistics:

The EC1.6 value was calculated according to the equation
EC1.6 = (a-c) [(1.6-d)/(b-d)] + c
where EC1.6 is the estimated concentration of the test item required to produce a 1.6-fold increase in draining lymph node cell proliferative activity; (a, b) and (c, d) are respectively the co-ordinates of the two pair of data lying immediately above and below the S.I. value of 1.6 on the local lymph node assay dose response plot.

For the statistical evaluation of BrdU values, ear weights, lymph node weights and lymph node cell counts, the Mann-Whitney-U test for non-parametric
comparison was applied

Results and discussion

Positive control results:

SI = 4.5

In vivo (LLNA)

Results

Parameter:

SI

Remarks on result:

other: 1%: SI = 1 2%: SI = 1.3 5%: SI = 1.8 EC1.6 = 3.8%

Any other information on results incl. tables

A significant increase in lymph node weights and cell counts were observed in the 5% group. Also, ear weights were significantly increased by 15% in this group, but remained below the threshold of excessive irritation (increase > 25%).

Applicant's summary and conclusion

Interpretation of results:

sensitising

Remarks:

Migrated information