N-[3-(dimethylamino)propyl]stearamide

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2012-10-22 to 2012-11-20

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:

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

Version / remarks:

May 2008

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Version / remarks:

adopted 24 April 2002

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

N-[3-(dimethylamino)propyl]stearamide

EC Number:

231-609-1

EC Name:

N-[3-(dimethylamino)propyl]stearamide

Cas Number:

7651-02-7

Molecular formula:

C23H48N2O

IUPAC Name:

N-[3-(dimethylamino)propyl]octadecanamide

Test material form:

solid: pellets

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Age at study initiation: at least 6 weeks
- Weight at study initiation: at least 1.0 kg
- Housing: individually in labelled cages with perforated floors and shelters
- Diet (e.g. ad libitum): Pelleted diet for rabbits ad libitum
- Water (e.g. ad libitum): tap water ad libitum
- Acclimation period: at least 5 d

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18 to 24°C
- Humidity (%): 40 to 70%
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 2012-10-22 To: 2012-11-20

Test system

Type of coverage:

semiocclusive

Preparation of test site:

clipped

Vehicle:

water

Controls:

not required

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 g of the test item

VEHICLE
- Amount(s) applied (volume or weight with unit): 0.7 mL

Duration of treatment / exposure:

first animal: initially 3 minutes on one flank, consecutively one hour and 4 hours (separate patches) on the other flank;
further two animals: 4 hours

Observation period:

7 days (animal one)
14 days (animals 2 and 3)

Number of animals:

3 (one sex)

Details on study design:

TEST SITE
- Area of exposure: 2x3 cm
- % coverage: no data
- Type of wrap if used: Micropore tape secured with Coban elastic bandage

REMOVAL OF TEST SUBSTANCE
- Washing (if done): treated skin was cleaned of residual test substance using water after removal of dressing
- Time after start of exposure: animal 1: 3 min/1 h / 4 h; animals 2 and 3: 4 h

SCORING SYSTEM: Draize scale (OECD guideline 404)

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

animal #1

Time point:

other: mean 24, 48, 72 h

Score:

1.6

Max. score:

4

Reversibility:

fully reversible within: 7 days

Results 2

Irritation parameter:

erythema score

Basis:

animal: #2, #3

Time point:

other: mean 24, 48, 72 h

Score:

2

Max. score:

4

Reversibility:

fully reversible within: 15 days

Results 3

Irritation parameter:

edema score

Basis:

animal #1

Time point:

other: mean 24, 48, 72 h

Score:

1

Max. score:

4

Reversibility:

fully reversible within: 7 days

Results 4

Irritation parameter:

edema score

Basis:

animal #2

Time point:

other: mean 24, 48, 72 h

Score:

1.3

Max. score:

4

Reversibility:

fully reversible within: 8 days

Results 5

Irritation parameter:

edema score

Basis:

animal #3

Time point:

other: mean 24, 48, 72 h

Score:

1

Max. score:

4

Reversibility:

fully reversible within: 8 days

Irritant / corrosive response data:

No skin irritation was seen after an exposure period of 3 minutes or 1 h to 0.5 g of the test substance.
4 h exposure to the test substance resulted in very slight or well defined erythema (score 1 - 2) and very slight or slight edema (score 1 - 2) in the treated skin areas of the three rabbits. Scaliness was seen in two animals after 7 days. The skin irritation resolved within 7 days after exposure in one animal and after
14 days in the other two animals.

Other effects:

No staining of the treated skin by the test substance was observed and no remnants of the test substance were present.
No symptoms of systemic toxicity were observed in the animals during the test period and no mortality occurred.

Any other information on results incl. tables

Table 1: INDIVIDUAL SKIN IRRITATION SCORES

 

Animal # 1	3 minutes treatment site			1-hour treatment site			4-hours treatment site
Time after bandage removal	Erythema	Oedema	comments	Erythema	Oedema	comments	Erythema	Oedema	comments
Immediately	0	0	-	0	0	-	0	1	-
1 hour	0	0	-	NS	NS	-	1	1	-
3 hours	NS	NS	-	0	0	-	NS	NS	-
4 hours	0	0	-	0	0	-	NS	NS	-
5 hours	0	0	-	NS	NS	-	NS	NS	-
24 hours	0	0	-	0	0	-	2	1	-
48 hours	0	0	-	0	0	-	2	1	-
72 hours	0	0	-	0	0	-	1	1	-
7 days	0	0	-	0	0	-	0	0	-

Comments:

NS. Not scored according to protocol.

l. Scaliness.

 

 

Animal #	2 (4-hours treatment)			3 (4-hours treatment)
Time after exposure	Erythema	Oedema	comments	Erythema	Oedema	comments
1 hour	1	1	-	1	1	-
24 hours	2	1	-	2	1	-
48 hours	2	2	-	2	1	-
72 hours	2	1	-	2	1	-
8 days	1	0	I	1	0	I
15 days	0	0	-	0	0	-

 

 

 

 

Table 2: MEAN VALUE IRRITATION SCORES AFTER 4 HOURS OF EXPOSURE

 

Animal #	Mean 24, 48 and 72 hrs
	Erythema	Oedema
1	1.6	1.0
2	2.0	1.3
3	2.0	1.0

 

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Judgment is based on erythema and edema calculated as mean scores for each animal following grading at 24, 48 and 72 hours after removal of the test material, in consideration of reversibility. The following mean scores were calculated: erythema 1.6/2.0/2.0 and edema 1.0/1.3/1.0. All effects were fully reversible within 7 days in one animal and after 14 days in the two other animals.

Executive summary:

In a primary dermal irritation study according to OECD Guideline 404, adopted 24 April 2002, and EU Method B.4, May 2008, 3 young adult New Zealand white rabbit of one sex were dermally exposed to 0.5 g of Stearic acid 3-(dimethylaminopropyl)amide (100% a.i) to 6 cm² skin surface. The first animal was subsequently exposed for 3 minutes, 1 and 4 hours. Two further animals were exposed for 4 hours. Animals then were observed for 7 (animal #1) or 14 days (animals #2, #3). 

 

In animal 1, no signs of skin reactions were recorded after removing the patch applied for 3 minutes and 1 hour in the observations carried out after removing the patches. After the 4 hours exposure to the test item, very slight oedema (grade 1) was observed one hour after removing the patch. Skin reactions observed in this animal during the observations made 24 and 48 hours after removing the patch were slight erythema (grade 2) and very slight edema (grade 1). After 72 hours, there was very slight erythema and very slight edema (grade 1) that was fully reversible within 7 days.

 

In animals 2 and 3, very slight edema (grade 1) and very slight erythema (grade 1) were observed 1 h after patch removal. At the 24, 48 and 72 h observations slight erythema (grade 2) and very slight or slight edema (grade 1 - 2) were noted. Scaliness was seen in these two animals after 7 days. The skin irritation resolved within 15 days.

The means of the erythema and edema evaluations at 24, 48 and 72 hours for the three animals after a four-hour exposure were 1.6, 2 and 2 (erythema) and 1, 1.3 and 1 (edema).

 

In this study, Stearic acid 3-(dimethylaminopropyl)amide is classified as not irritating to rabbit skin according the criteria of CLP, EU GHS (Regulation (EC) No 1272/2008).