Docosanoic acid

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Justification for type of information:

data is from experimental reports

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2013

Report date:

2013

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Principles of method if other than guideline:

To evaluate the dermal irritation potential of the test chemical in New Zealand white rabbits

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Docosanoic acid

EC Number:

204-010-8

EC Name:

Docosanoic acid

Cas Number:

112-85-6

Molecular formula:

C22H44O2

IUPAC Name:

docosanoic acid

Test material form:

solid: crystalline

Details on test material:

- Name of test material (as cited in study report): docosanoic acid
- Molecular Formula: C22H44O2
- Molecular weight: 340.33 g/mol
- Substance type: Organic
- Physical state: solid

Specific details on test material used for the study:

- Name of test material (as cited in study report): docosanoic acid
- Molecular Formula: C22H44O2
- Molecular weight: 340.33 g/mol
- Substance type: Organic
- Physical state: solid

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

-Source : In-bred
-Age : 10 to 12 weeks
-Body weight range : 2.0kg±200g
-Identification : By cage tag and corresponding colour body marking.
-Acclimatization : The healthy rabbits selected for study was acclimatized to standard laboratory condition for one week in experimental room under Veterinary examination.
-Randomization : After acclimatization and Veterinary examination three females were randomly selected.
-Accommodation : Animals were housed individually in stainless steel cages provided with stainless steel mesh bottom and facilities for food and water bottle.
-Diet : Pelleted feed
-Water : Community tap water passed through ‘Aqua Guard on line water filter’, was kept in glass bottles, ad libitum.

ENVIRONMENTAL CONDITIONS
- Temperature (°C):22-25 deg.C
- Humidity (%): 40-60%
- Air changes (per hr): 10-15 air changes per hour
- Photoperiod (hrs dark / hrs light):12 hours artificial fluorescent light and 12 hours dark.

Test system

Type of coverage:

occlusive

Preparation of test site:

clipped

Vehicle:

unchanged (no vehicle)

Controls:

not specified

Amount / concentration applied:

0.5 gm of test compound

Duration of treatment / exposure:

4 hrs.

Observation period:

14 days

Number of animals:

Three female rabbits

Details on study design:

Details on study design
TEST SITE
- Area of exposure: dorsal area of the trunk
- % coverage:approx 6 square cm
- Type of wrap if used: impervious dressing
REMOVAL OF TEST SUBSTANCE
- Washing (if done): yes
- Time after start of exposure: after patch removal, the site of application was cleaned with luke warm
water
OBSERVATION TIME POINTS
(indicate if minutes, hours or days) : 1, 24,48 and 72 hours
SCORING SYSTEM: The intact skin site of application was observed for erythema and edema and scored according to Draize method

Results and discussion

In vivo

Results

Irritation parameter:

overall irritation score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Reversibility:

not specified

Remarks on result:

no indication of irritation

Irritant / corrosive response data:

Skin reaction:
The test compound when applied at the dose level of 0.5 gm on shaven back skin (approximately 6 cm2) of rabbit produced Mild Erythema the site of application of test compound after four hour patch removal upto 48 hours.

Other effects:

Clinical signs:
The test compound applied on the shaven back skin of rabbit at the dose level of 0.5 gm did not produce any clinical signs of toxicity throughout the examination period of 14 days.

Any other information on results incl. tables

INDIVIDUAL ANIMAL DERMAL IRRITATION SCORES

Rabbit No.	Sex	INTACT SKIN
		3 Min.		4 Hours		24 Hours		48 Hours		72 Hours		14 days
		Erythema	Oedema	Erythema	Oedema	Erythema	Oedema	Erythema	Oedema	Erythema	Oedema	Erythema	Oedema
01	F	0	0	1	0	0	0	0	0	0	0	0	0
02	F	-	-	2	0	0	0	0	0	0	0	0	0
03	F	-	-	1	0	0	0	0	0	0	0	0	0
Total		0	0	4	0	0	0	0	0	0	0	0	0
Mean		0	0	1.33	0	0	0	0	0	0	0	0	0
Grand Total		0.00

 

Dermal Irritation Index: 1.33/4 = 0.33

TABLE – 2

CLINICAL SIGNS

 

SEX	ANIMAL NO.	Time (Min.)	Time (Hours)					Time (Day)
		3	1	4	24	48	72	14
FEMALE	01	N	N	N	N	N	N	N
	02	N	N	N	N	N	N	N
	03	N	N	N	N	N	N	N

 

N: No Clinical Signs

C: Clinical Signs Observed

 

Applicant's summary and conclusion

Interpretation of results:

other: not irritating

Conclusions:

The dermal irritation index of the test chemical in New Zealand white rabbits was calculated as 0.00 and test compound can be classified under "Not Classified".

Executive summary:

A dermal irritation study was conducted on New Zealand white rabbits in accordance with OECD 404 to assess the irritation parameter of the test chemical.

In the initial test one healthy rabbit of body weight 2.21 kg was selected for the study after acclimatization. The test compound in the amount of 0.5 gm was applied at the different sites on the shaven back skin of animal. The hairs of back sides were removed (approximately 6 cm²) one day earlier before the treatmentThe test substance in the amount of 0.5 gm was applied to a small area (approximately 6 cm²) of skin and covered with a gauze patch, which was held in place with non-irritating tape. The first patch was applied on the shaven back skin of rabbit and removed after three minutes. No serious reaction was observed at the site of application. The second patch was applied on the different shaven back side and removed after one hour. There were no signs of skin reaction observed at this site of application. Finally, a third patch was applied at a different site and was removed after four hour.Mild Erythema was observed at the site of application of test compound after four hour patch removal upto 48 hours.Finally, the animal was observed for 14 days, for any irritation and corrosion.

Because no corrosive effect observed in the initial test, a confirmatory test was done in order to confirm the irritant or negative response of the test substance by using two additional animals. In the confirmatory test the test compound in the amount of 0.5 gm was applied on the shaven back skin of two animals, each with one patch, for an exposure period of four hours. After four hours the patch was removed and the skin reactions were graded according to Draize’s method. The test compound when applied dermally on New Zealand White rabbit in the amount of 0.5 gm produced Mild Erythema at the site of application of test compound after four hour patch removal upto 48 hours. However, there was no corrosivity of the test compound was observed during the entire observation period of 14 days. The dermal irritation index of the test chemical in  New Zealand white rabbits was calculated as 0.00 and test compound can be classified under "Not Classified".