N-[3-(dimethylamino)propyl]docosanamide

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

2009-12-10 to 2012-12-26

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2009

Report date:

2009

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 (C18) and N-[3-(dimethylamino)propyl]docosanamide (C22) 50:50 (w/w %)

IUPAC Name:

N-[3-(dimethylamino)propyl]stearamide (C18) and N-[3-(dimethylamino)propyl]docosanamide (C22) 50:50 (w/w %)

Details on test material:

- Chemical name: 50:50 (w/w %) N-[3-(dimethylamino)propyl]stearamide (C18) and N-[3-(dimethylamino)propyl]docosanamide (C22)
- Physical state: solid
- Analytical purity: 99%

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Age at study initiation: 18 weeks (male), 15 weeks (female)
- Weight at study initiation: 2598 g (male), 2235-2509 g (females)
- Housing: Individually in stainless steel cages equipped with feed hoppers abd drinking water bowles. Wood blocks and haysticks 4642 were provided for gnawing
- Diet (e.g. ad libitum): Pelleted standard Provimi Kliba 3418 diet for rabbits ad libitum
- Water (e.g. ad libitum): tap water from Füllinsdorf ad libitum
- Acclimation period: at least 5 d

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 17 to 23°C
- Humidity (%): 30 to 70%
- Air changes (per hr): 10-15
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 2009-12-10 To: 2009-12-26

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): 0.5 mL

Duration of treatment / exposure:

4 hours

Observation period:

10 days

Number of animals:

1 male, 2 females

Details on study design:

TEST SITE
- Area of exposure: 2.5 x 2.5 cm
- % coverage: no data
- Type of wrap if used: restrainer bandage wrap around the abdomen

REMOVAL OF TEST SUBSTANCE
- Washing (if done): treated skin was cleaned of residual test substance using lukewarm tap water after removal of dressing
- Time after start of exposure: 4 hours

SCORING SYSTEM: Commision Regulation (EC) No 440/2008, B.4

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

2

Max. score:

4

Reversibility:

fully reversible within: 7 days

Results 2

Irritation parameter:

erythema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

1.67

Max. score:

4

Reversibility:

fully reversible within: 7 days

Results 3

Irritation parameter:

erythema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Max. score:

4

Results 4

Irritation parameter:

edema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

4

Results 5

Irritation parameter:

edema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0.67

Max. score:

4

Reversibility:

fully reversible within: 72 hours

Results 6

Irritation parameter:

edema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Max. score:

4

Irritant / corrosive response data:

One hour after test item exposure a very slight erythema was observed in the first treated female and in the male which progressed into a well-defined erythema at the 24-hour reading and persisted well-defined or very slight up to the 72-hour reading in both animals- A very light swelling was recorded in the first treated female 24 and 48 hours after removal of the dressing. Scaling was present on the skin of the male on day 7.

Other effects:

No staining produced by the test item of the treated skin was observed. No clinical signs were observed in the animals during the test period and no mortality occurred. All animals lost body weight during acclimatisation (1.2%-8.3%) but recovered until end of the study.

Any other information on results incl. tables

Table 1: INDIVIDUAL SKIN IRRITATION SCORES

 

Animal #	1 (male)			2 (female)			3 (female)
Time after exposure	Erythema	Oedema	comments	Erythema	Oedema	comments	Erythema	Oedema	comments
1 hour	1	0	-	1	0	-	0	0	-
24 hours	2	0	-	2	1	-	0	0	-
48 hours	2	0	-	2	1	-	0	0	-
72 hours	2	0	-	1	0	-	0	0	-
7 days	0	0	I	0	0	-	0	0	-
10 days	0	0	-	0	0	-	0	0	-

 

Comments:

l. Scaling

 

 

 

 

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 2.00/1.67/0.00 and edema 0.00/0.67/0.00. These effects were fully reversible within 7 days. Scaling was present on the skin of one animal on day 7.

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 adult New Zealand white rabbits (1 male, 2 females) were dermally exposed to 0.5 g of N-[3-(dimethylamino)propyl]stearamide (C18) and N-[3-(dimethylamino)propyl]docosanamide (C22) 50:50 (w/w %) (99 % a.i., moistened with 0.5 ml water) to 6.25 cm² skin surface. Animals then were observed for 10 days.

Irritation was scored by the method of the numerical scoring system listed in the Commission Regulation (EC) No 440/2008, B.4.

One hour after test item exposure a very slight erythema was observed in the first treated female and in the male which progressed into a well-defined erythema at the 24-hour reading and persisted well-defined or very slight up to the 72-hour reading in both animals- A very light swelling was recorded in the first treated female 24 and 48 hours after removal of the dressing. Scaling was present on the skin of the male on day 7. In this study, N-[3-(dimethylamino)propyl]stearamide (C18) and N-[3-(dimethylamino)propyl]docosanamide (C22) 50:50 (w/w %) is classified as not irritating to rabbit skin according the criteria of CLP, EU GHS (Regulation (EC) No 1272/2008).