Pentanediamide, N1,N5-dibutyl-2-[(2-ethyl-1-oxohexyl)amino]-, (2S)-

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

27 February 2001 - 9 March 2001

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2001

Report date:

2001

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

EU Method B.4 (Acute Toxicity: Dermal Irritation / Corrosion)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

(2S)-N,N'-dibutyl-2-(2-ethylhexanamido)pentanediamide

EC Number:

700-664-8

Cas Number:

486455-65-6

Molecular formula:

C21H41N3O3

IUPAC Name:

(2S)-N,N'-dibutyl-2-(2-ethylhexanamido)pentanediamide

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

Test Animals:
Source: Elevage Scientifique des Dombes
F-01400 Chatillon sur Chalaronne, France
Number of animals: 1 male and 2 females
Age at start of treatment: 11-12 weeks (male) 9-11 weeks (females)
Body weights at start of treatment : 2.3-2.5 kg
Identification: By unique cage number and corresponding ear number.
Acclimatization: Under laboratory conditions after health examination. Only animals without any visual signs of illness were used for the study.
Allocation: Male No. 7 Female Nos. 8 and 9

Husbandry:
Room no.: 106 / RCC Ltd, Füllinsdorf
Conditions: Standard Laboratory Conditions
Air-conditioned with target ranges for room temperature 20 ± 3 °C, relative humidity 30-70 % and approximately 10-14 air changes per hour. Room temperature and humidity were monitored continuously and values outside of these ranges may have occasionally occurred, usually following room cleaning. These transient variations are considered not to have any influence on the study and, therefore, these data are not reported but are retained at RCC. The animals were provided with an automatically controlled light cycle of 12 hours light and 12 hours dark. Music was played during the light period.
Accommodation: Individually in stainless steel cages equipped with feed hoppers, drinking water bowls, with autoclaved wood (RCC Ltd, Fullinsdorf) and haysticks for gnawing.
Diet: Pelleted standard Provimi Kliba 3418 rabbit maintenance diet ad libitum (batch no. 33/00) provided by Provimi Kliba AG, CH-4303 Kaiseraugst. Results of analysis are archived at RCC Ltd, Itingen. Haysticks (QS no. 11/01) provided by Eberle Nafag AG, CH-9200 Gossau.
Water: Community tap water from Fullinsdorf, ad libitum. Results of bacteriological, chemical and contaminant analyses are archived at RCC Ltd, Itingen.

Test system

Type of coverage:

semiocclusive

Preparation of test site:

shaved

Vehicle:

water

Remarks:

test material moistened with approximately 0.1 ml bi-distilled water before application

Controls:

not required

Amount / concentration applied:

0.5 g (per animal) of test material was weighed as delivered by the sponsor and then moistened with bi-distilled water before application.

Duration of treatment / exposure:

4 hours

Observation period:

72 hours

Number of animals:

3

Details on study design:

Treatment:
Four days before treatment, the left flank was clipped with an electric clipper, exposing an area of approximately 100 cm² (10 cm x 10 cm). The skin of the animals was examined one day before treatment, and regrown fur of all animals was again clipped.
Animals with overt signs of skin injury or marked irritation which may have interfered with the interpretation of the results were not used in the test.
On the day of treatment, 0.5 g of test material was placed on a surgical gauze patch (ca. 2.5 cm x 2.5 cm). This gauze patch was applied to approximately 6 cm² of the intact skin of the clipped area. The patch was covered with a semi-occlusive dressing [Isoelast Heftpflaster Acryl 8 x 75 cm]. The dressing was wrapped around the abdomen and anchored with tape.
The duration of treatment was 4 hours. Then the dressing was removed and the skin was flushed with lukewarm tap water to clean the application site so that any reactions (erythema) were clearly visible at that time.

Observations:
Viability/Mortality: Daily from delivery of the animals to the termination of test.
Clinical signs: Daily from delivery of the animals to the termination of test.
Body weights: At start of acclimatization, on the day of application and at termination of observation.

Irritation Scores:
The skin reaction was assessed according to the numerical scoring system listed in the EEC Commission Directive 92/69/EEC, July 31, 1992 (based on the Draize score system) approximately 1, 24, 48 and 72 hours after the removal of the dressing, gauze patch and test item.
If evident, corrosive or staining properties of the test item were described and recorded.

Necropsy:
No necropsy was performed in the animals sacrificed at termination of observation.
All rabbits were sacrificed by an intravenous injection of NARCOREN (Rhône Mérieux GmbH, D-88471 Laupheim) into the ear vein at a dose of at least 1 ml/kg body weight (equivalent to 160 mg sodium pentobarbitone/kg body weight) and discarded.

No statistical analysis was performed.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

0

Reversibility:

fully reversible

Results 2

Irritation parameter:

edema score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

0

Reversibility:

fully reversible

Irritant / corrosive response data:

Application of the test item to healthy intact rabbit skin resulted in a primary irritation index of 0.00.
The test item did not elicit any skin reactions at the application site of any animal at any of the observation times (all scores 0). The mean values from 24 to 72 hours were therefore 0 for erythema and 0 for oedema.
No staining by the test item of the treated skin was observed.
No irreversible alterations of the treated skin were observed nor were corrosive effects evident on the skin.

Other effects:

No clinical signs of systemic toxicity were observed in the animals during the study and no mortality occurred.
The body weights of all rabbits were considered to be within the normal range of variability.

Applicant's summary and conclusion

Interpretation of results:

other: Not classified according to EU criteria

Conclusions:

According to Regulation (EC) No 1272/2008, the test material does not require classification as a skin irritant.

Executive summary:

In a skin irritation study (793642) according to EU Test Method B.4, the primary skin irritation potential of the test material was investigated by topical semi-occlusive application of 0.5g to 6 cm² intact left flank of each of three young adult New Zealand White rabbits. The duration of treatment was four hours. The scoring of skin reactions was performed 1, 24, 48 and 72 hours after removal of the dressing. The scores of each animal at the following reading times (24, 48, 72 hours) were used in calculating the respective mean values for each type of lesion.

The test item did not elicit any skin reactions at the application site of any animal at any of the observation times (all scores 0). The mean values from 24 to 72 hours were therefore 0 for erythema and 0 for oedema.

The test item caused no staining of the treated skin.

No corrosive effects were noted on the treated skin of any animal at any measuring interval.

According to Regulation (EC) No 1272/2008, the test material does not require classification as a skin irritant.