Amides, C18 (unsaturated)

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP study with certificate and no deviations. Complete test article characterization available. Reliability was changed from "1" to "2" according to the ECHA guidance document "Practical guide 6: How to report read-across and categories".

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

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

Constituent 1

Reference substance name:

(Z)-docos-13-enamide

EC Number:

204-009-2

EC Name:

(Z)-docos-13-enamide

Cas Number:

112-84-5

Molecular formula:

C22H43NO

IUPAC Name:

docos-13-enamide

In vivo test system

Test animals

Species:

mouse

Strain:

CBA

Sex:

female

Details on test animals and environmental conditions:

Animals were randomly allocated to cages. Females were nulliparous and non-pregnant. After an acclimation period of at least five days, animals were selected at random and assigned a number unique within the study. Animals were housed singly in solid-floor polypropylene cages with granulated softwood bedding. Food and tap water were available ad lib. Temperature was controlled to 20-24 °C; relative humidity was controlled to 18-65%. Rate of air exchange was ten - fifteen changes per hour. Lighting was controlled to give 12 hours continuous light and 12 hours continuous darkness.

Study design: in vivo (LLNA)

Vehicle:

other: tetrahydrofuran

Concentration:

0, 5, 10 and 25% w/v

No. of animals per dose:

Five

Details on study design:

Each test group of mice was treated by topical (epidermal) application to the dorsal surface of each ear (left and right) with different test item concentrations of 5, 10, and 25% (w/v) in tetrahydrofuran. The application volume, 25 µl, was spread over the entire dorsal surface (8 mm) of each ear once daily for three consecutive days. A further group of mice was treated with an equivalent volume of the vehicle alone (control animals). Five days after the first topical application, all mice were administered with 250 µl of 78.3 µCi/ml 3HTdR (corresponds to 19.6 µCi 3HTdR per mouse) by intravenous injection via a tail vein. Approximately five hours after treatment with 3HTdR all mice were euthanised by intraperitoneal injection of Pentobarbital-Natrium (Release®, WDT, 30827 Garbsen, Germany).

The draining lymph nodes were rapidly excised and pooled for each animal (2 nodes per animal). Single cell suspensions (in phosphate buffered saline) of pooled lymph node cells were prepared by gentle mechanical disaggregation through stainless steel gauze (200 µm mesh size). After washing two times with phosphate buffered saline (approx. 10 ml) the lymph node cells were resuspended in 5 % trichloroacetic acid (approx. 3 ml) and incubated at approximately +4 °C for at least 18 hours for precipitation of macromolecules. The precipitates were then resuspended in 5 % trichloroacetic acid (1 ml) and transferred to plastic scintillation vials with 10 ml of ‘Ultima Gold’ scintillation liquid (Perkin Elmer (LAS) GmbH, 63110 Rodgau, Germany) and thoroughly mixed.

The level of 3HTdR incorporation was then measured on a ß-scintillation counter (Tricarb 2900 TR, Perkin Elmer (LAS) GmbH, 63110 Rodgau, Germany). Similarly, background 3HTdR levels were also measured in two 1ml-aliquots of 5 % trichloroacetic acid. The ß-scintillation counter expresses 3HTdR incorporation as the number of radioactive disintegrations per minute (DPM).

Positive control substance(s):

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

Results and discussion

Positive control results:

Results of the GLP Positive Control Experiment performed in November 2009:
Positive control substance: α-Hexylcinnamaldehyde
Vehicle: acetone:olive oil (4+1)
Test item concentration % (w/v): 0, 5, 10, 25
Stimulation indices (based on mean DPM/node of each group): 0%: 1.0; 5%: 1.21; 10%: 2.09; 25%: 6.22

In vivo (LLNA)

Results

Results 1

Parameter:

SI

Remarks on result:

other: 0%: 1.0; 5%: 0.81; 10%: 0.84; 25%: 0.70

Results 2

Parameter:

other: disintegrations per minute (DPM)

Remarks on result:

other: See table below

Any other information on results incl. tables

Test item concentration			DPM values measured	DPM-BG per animal (2 lymph nodes)^a)	S.I.^b)
% (w/v)	Group No.	Animal No.
---	BG I	---	65	---	---
---	BG II	---	21	---	---
0	1	1	1259	1216	---
0	1	2	2080	2037	---
0	1	3	822	779	---
0	1	4	1101	1058	---
0	1	5	622	579	---
5	2	6	741	698	0.6
5	2	7	1097	1054	0.9
5	2	8	1213	1170	1.0
5	2	9	696	653	0.6
5	2	10	1036	993	0.9
10	3	11	1239	1196	1.1
10	3	12	974	931	0.8
10	3	13	779	736	0.6
10	3	14	596	553	0.5
10	3	15	1372	1329	1.2
25	4	16	953	910	0.8
25	4	17	550	507	0.4
25	4	18	916	873	0.8
25	4	19	587	544	0.5
25	4	20	1174	1131	1.0

BG   =   Background (1 ml 5% trichloroacetic acid) in duplicate

1      =   Control Group

2-4  =   Test Group

S.I.   =   Stimulation Index

^a)     =   values corrected for mean background value (BGI and BGII).

^b)          =     Stimulation Indices relative to the mean of the control group (Group 1)

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information

Conclusions:

The test item Erucamide was not a skin sensitizer under the test conditions of this study.

Executive summary:

In the study the test item Erucamide, dissolved in tetrahydrofuran, was assessed for its possible skin sensitization potential. For this purpose a local lymph node assay was performed using test item concentrations of 5, 10, and 25% (w/v). The animals did not show any signs of local skin irritation or systemic toxicity during the course of the study and cases of mortality were not observed. In this study Stimulation Indices (S.I.) of 0.81, 0.84 and 0.70 were determined with the test item at concentrations of 5, 10, and 25% (w/v) in tetrahydrofuran, respectively.

The test item Erucamide was not a skin sensitizer under the test conditions of this study.