Pentanamide, N-(1-cyanocyclopentyl)-

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Experimental start date: 17 october 2012 - Experimental completion date: 4 december 2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: OECD, GLP study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2012

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

Type of study:

mouse local lymph node assay (LLNA)

Test material

Test material information

Constituent 1

Reference substance name:

N-(1-cyanocyclopentyl)pentanamide

EC Number:

928-489-4

Cas Number:

194984-24-2

Molecular formula:

C11H18N2O

IUPAC Name:

N-(1-cyanocyclopentyl)pentanamide

Test material form:

other: 100 % solution

Details on test material:

Identification: Valeroyl-aminonitrile oil
Description: Liquid
Lot/batch number: 2U291
Certificate of analysis: 13 september 2012
Storage conditions bulk material: between 2°C and 8°C
Purity: 92.4°C
Expiry date: september 2013

In vivo test system

Test animals

Species:

mouse

Strain:

other: BALB/c N

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories France, Les Oncins, BP0109, 69592 L'Arbresle Cedex, France
- Age at study initiation: approx. 8 to 12 weeks
- Weight at study initiation: approx. 20 +/- 4 g
- Total No. of animals on study: 4 animals/group
- Housing: Housed 4/cage in type "1290D" cages made of transparent polycarbonate. Space allocated: 820 cm² x 15.5 cm
- Diet (e.g. ad libitum): Irradiated controlled pelleted rodent diet (re. AO4C-10, SAFE)
- Water (e.g. ad libitum): free acess to tap water through bottles
- Acclimation period: for at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20°C to 24°C
- Humidity (%): 40 to 75 %
- Photoperiod (hrs dark / hrs light): 12h/12h cycle

Study design: in vivo (LLNA)

Vehicle:

unchanged (no vehicle)

Concentration:

100 %

No. of animals per dose:

4

Details on study design:

Experimental schedule:
- Day 1 to day 3: treatment (once daily): open application of 25 µL of the appropriate dilution of the test article or the positive control , or the vehicle alone to the dorsum of both ears.
- Day 4 and day 5: no treatment
- Day 6: injection (tail vein) of 250 µL of sterile phosphate-buffered saline (D-PBS) containing 20 µCi of 3H-methylthymidine to all animals. Approximately five hour later, animals will be sacrified and the draining auricular lymph nodes excised and pooled in D-PBS for each experimental group.

Preparation of cell suspension:
A signle cell suspension of lymph node cells (LNC) is prepared for each pooled sample by gentle mechanical disaggregation through 100 µm Nylon Cell Strainer. The cells are washed twice with an excess of D-PBS and DNA precipitated with 5% trichloroacetic acid (TCA) for approximately 18 hours, in the refrigerator. After centrifugation, the supernatant is discarded and the pellet resuspended in 1mL TCA and transferred to vials, then 10 mL of scintillation fluid for 3H- counting are added.

Determination of incorporated 3H-methyl thymidine
Incorporation of 3H-methyl thymidine is measured by beta-scintillation counting as disintegrations per minute (DPM) for each experimetal group (total DPM) with a beta-scintillation counter Wallac.

Criteria used to consider a positive response: A test article is considered as a skin sensitizer when the stimulation index (SI) >= 3

Positive control substance(s):

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

Statistics:

No statistical analysis was performed.

Results and discussion

Positive control results:

HCA at 25% :
Total DPM/group: 17339.2;
Mean DPM/node: 2167.4;
Simulation index: 13.2
Acceptance criteria validated: SI is greater than 3

In vivo (LLNA)

Results

Results 1

Parameter:

SI

Remarks on result:

other: 4.5

Results 2

Parameter:

other: disintegrations per minute (DPM)

Remarks on result:

other: Total DPM/group: 5877.1 Mean DPM/node: 734.6

Any other information on results incl. tables

No mortality was observed during the study.

No systemic toxicity or local irritation on application sites were noted in any of the treated animals.

Body weight variations in Valeroil-aminonitrile-treated group animals were similar to those observed in the vehicle control group animals.

Applicant's summary and conclusion

Interpretation of results:

sensitising

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

In conclusion, under these experimental conditions, the test article Valeroil-aminonitrile was found positive in the local lymph node assay and has to be classified as a skin sensitizer in Category 1 of the Globally Harmonized Classification System (GHS).