Docosanoic acid

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

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 study report.

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 402 (Acute Dermal Toxicity)

Principles of method if other than guideline:

The study was conducted to determine the mortality, clinical sign of toxicity and histopathological effect of the given test chemical at different dose level in wistar albino rats.

GLP compliance:

no

Test type:

other: Acute Dermal Toxicity

Limit test:

yes

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: particulate/powder

Details on test material:

- Name of test material (as cited in study report): docosanoic acid
- Substance type: Organic
- Physical state: Solid White powder

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

-Source : In-bred
-Age : 8 to 10 weeks.
-Body weight range :200±20g
-Identification : By cage tag and corresponding colour body marking.
-Nutritional conditions : Animals were fasted overnight prior to test and food was offered three hours after dosing.
-Housing : Groups of two animals of same sex in polypropylene cages with stainless steel grill top, facilities for food and water bottle, and bedding of clean paddy husk.
-Diet : Pelleted feed
-Water : Fresh and clean water filtered through ‘Aqua Guard on line water filter’, was kept in glass bottles Ad libitum
-Acclimatization :The healthy wistar albino rats selected for study acclimatized to standard laboratory condition for period of one week under close Veterinary supervision.
-Randomization : After acclimation and Veterinary examination all the animals randomly divided into two groups and each group having five male and five female rats.

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.

Administration / exposure

Type of coverage:

occlusive

Vehicle:

other: distilled water

Details on dermal exposure:

TEST SITE
- Area of exposure: back skin of total body surface area
- % coverage: Approximate 10 percent
- Type of wrap if used: The test substance was applied uniformly over an exposed area of skin. The test compound was held in contact with the skin with an impervious dressing secured in place with an adhesive tape.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): The dressing was removed and the site of application was cleaned with lukewarm water wiping the test compound.
- Time after start of exposure:24 hours

VEHICLE
- Amount(s) applied (volume or weight with unit):0.5 gm
- Dose preparation: Preparation of the test article was done freshly, few minutes prior to dosing. Test substance was moistened with distilled water.

Duration of exposure:

24 hours

Doses:

Group-I - 2000 mg/kg b. wt
Group-II - 2000 mg/kg b. wt

No. of animals per sex per dose:

Group-I - 2000 mg/kg b. wt - 10 (5 male & 5 female)
Group-II - 2000 mg/kg b. wt - 10 (5 male & 5 female)

Control animals:

not specified

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: All the animals were observed for mortality at 30 minutes time interval for first six hours on the day of test compound administration and thereafter twice a day for 14 days.
The treated animals were closely observed for clinical signs of intoxication, first 4 hours and thereafter for every 1 hrs interval for 24 hrs after dosing and twice a day for 14 days. All the rats were observed at least twice daily with the purpose of recording any symptoms of ill-health or behavioral changes. These observations included changes in skin and fur in the eyes and mucous membranes, respiratory, circulatory, central nervous and autonomous systems, somatomotor activity and behavior changes. The following clinical signs were observed in rats to characterize with erythema, hypersensitivity, edema etc.
The body weight of all the animals was observed weekly on day 0 (pre treatment), 7th and 14th (post treatment).
- Necropsy of survivors performed: yes, necropsy was carried out on all the animals that died during the study or surviving animals were sacrificed at the end of the study to observe any gross pathological changes.

Statistics:

not specified

Results and discussion

Preliminary study:

not specified

Effect levels

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Remarks on result:

other: No incidence of mortality was observed

Mortality:

No incidence of mortality was observed in wistar albino rats after application of test compound. The period of application of test compound was 24 hours

Clinical signs:

other: The wistar albino rats treated with the test compound did not show any clinical signs of intoxication throughout the period of observation.

Gross pathology:

NECROPSY FINDING
EXTERNAL
Skin- Skin and hair coat was observed wet.
All external orifices- Normal

INTERNAL
Subcutaneous- No changes were observed.
Superficial and deep lymph nodes- No change in mesenteric lymph node.

ABDOMINAL CAVITY
Opening and general examination- In the abdominal cavity all the organs were present in normal position.
Spleen- No changes were recorded.
Digestive system- No gross changes were observed in stomach and intestine.
Liver and biliary ducts- No gross pathological changes were observed
Excretory system- No gross pathological changes were observed.
Adrenal- Observed normal.
Male/female genital organs – Showed normal colour, consistency and no inflammatory changes.

THORACIC CAVITY
Opening and general examination- Thoracic cavity was found to be normal without any fluid, mucous or blood etc.
Lungs- No changes were recorded.
Heart- No changes were observed in color and consistency. Heart found normal.
Thyroid- Normal in shape, size and surface.

3. CRANIAL CAVITY
Brain- Normal in shape and size.

Other findings:

not specified

Any other information on results incl. tables

TABLE – 2

SUMMARY OF BODY WEIGHT (GM)

Group	Animal ID	Day 0	Day 7	% Gain/loss	Day 14	% Gain/loss
Group-I 2000 mg/kg b. wt	201319-1	200.4	206.9	3.24	213.4	6.48
	201319-2	205.7	213.3	3.69	219.6	6.75
	201319-3	202.9	209.4	3.20	214.1	6.60
	201319-4	206.4	212.3	2.85	220.3	6.73
	201319-5	204.9	211.4	3.17	219.9	7.31
	201319-6	202.02	210.02	3.99	219.00	8.40
	201319-7	200.99	209.98	4.47	218.89	8.90
	201319-8	201.46	210.64	4.5	217.32	7.8
	201319-9	206.56	217.54	5.3	221.47	7.2
	201319-10	204.67	209.46	2.3	217.75	6.3
Group-II 2000 mg/kg b. wt	201319-11	203.31	210.10	3.3	216.42	6.4
	201319-12	194.6	199.3	2.41	206.8	6.26
	201319-13	201.23	206.99	2.86	211.56	5.13
	201319-14	205.41	210.23	2.34	218.13	6.19
	201319-15	198.28	204.87	3.32	210.30	6.06
	201319-16	201.56	207.12	2.75	214.05	6.19
	201319-17	203.55	208.98	2.66	215.88	6.05
	201319-18	205.4	211.4	2.92	214.4	4.38
	201319-19	204.2	210.3	2.98	215.3	5.43
	201319-20	203.1	209.4	3.10	215.2	5.95

TABLE – 3

CLINICAL SIGNS AND MORTALITY

Parameters	Incidence of Clinical Signs Observed after Dosing on																			Mortality
	Day 0					DAY
	Min	Hour
	30	1	2	4	6	1	2	3	4	5	6	7	8	9	10	11	12	13	14	Total	%
Mortality (total)	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0/10	0
Clinical Signs- Local
Redness	-	-	-	-	-	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Pain	-	-	-	-	-	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Swelling	-	-	-	-	-	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Systemic signs
	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0

Group: I Limit test                                                                        Dose: 2000 mg/kg b.wt

                                                                                                                                                          

 

-          =Observed after 24 hrs

0        = No clinical signs

+        = Mild

++      = Moderate

+++    = High

++++  = Severe

TABLE – 3 Contd…………….

CLINICAL SIGNS AND MORTALITY

Group: II Confirmatory test                                                        Dose: 2000 mg/kg b.wt

                                                                                                                                              

Parameters	Incidence of Clinical Signs Observed after Dosing on																			Mortality
	Day 0					DAY
	Min	Hour
	30	1	2	4	6	1	2	3	4	5	6	7	8	9	10	11	12	13	14	Total	%
Mortality (total)	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0/10	0
Clinical Signs- Local
Redness	-	-	-	-	-	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Pain	-	-	-	-	-	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Swelling	-	-	-	-	-	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Systemic signs
Clinical signs	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0

 

-          =Observed after 24 hrs

0        = No clinical signs

+        = Mild

++      = Moderate

+++    = High

++++  = Severe

TABLE – 4

SUMMARY OF NECROPSY FINDINGS

S. No.	Fate	Wistar albino rats
		Dose (mg/kg b. wt)
		2000 (limit test)	2000 (confirmatory test)
1	Terminal sacrifice	10/10	10/10
2	Found Dead	0/10	0/10
3	Abnormalities detected	0/10	0/10

TABLE – 5

INDIVIDUAL ANIMAL FATE & NECROPSY FINDINGS

Group-I (limit test)                                                                         2000 mg/kg b.wt.

Animal ID	Fate	Time	Gross Findings
201319-1	TS	Day 15	NAD
201319-2	TS	Day 15	NAD
201319-3	TS	Day 15	NAD
201319-4	TS	Day 15	NAD
201319-5	TS	Day 15	NAD
201319-6	TS	Day 15	NAD
201319-7	TS	Day 15	NAD
201319-8	TS	Day 15	NAD
201319-9	TS	Day 15	NAD
201319-10	TS	Day 15	NAD

Day 0 is the day of dose administration.

TS- Terminal Sacrifice

NAD- No abnormality Detected

FD-Found dead

TABLE-5 Contd………..

INDIVIDUAL ANIMAL FATE & NECROPSY FINDINGS

Group: II(confirmatory test)                                                     Dose: 2000 mg/kg b.wt.                                                                                

Animal ID	Fate	Time	Gross Findings
201319-11	TS	Day 15	NAD
201319-12	TS	Day 15	NAD
201319-13	TS	Day 15	NAD
201319-14	TS	Day 15	NAD
201319-15	TS	Day 15	NAD
201319-16	TS	Day 15	NAD
201319-17	TS	Day 15	NAD
201319-18	TS	Day 15	NAD
201319-19	TS	Day 15	NAD
201319-20	TS	Day 15	NAD

Day 0 is the day of dose administration.

TS- Terminal Sacrifice

NAD- No abnormality Detected

FD-Found dead

 

Applicant's summary and conclusion

Interpretation of results:

other: Not classified

Conclusions:

Based on the results obtained from present investigation, it can be concluded that the LD50 value was considered to be >2000 mg/kg bw, when Wistar albino rats treated with the test chemical applied dermally on the shaven back skin. Hence, the given test chemical is acutely non toxic.

Executive summary:

The acute dermal toxicity study of the given test chemical was conducted according to OECD guideline 402 for testing of chemicals on Wistar albino rats. The summary of the study was as follows -

Limit Test (2000 mg/kg b.wt):

Ten healthy wistar albino rats of both sexes (ranging b.wt 200±20 gm) were selected for the study after acclimatization. Approximate 10 percent back skin of total body surface area was prepared 24 hrs prior to application of test compound. The test compound was applied dermally at the dose level of 2000 mg/kg b.wt to each animal. The treated animals were observed for clinical signs of intoxication and mortality at different time interval for a period of 14 days. The body weight of each rat was observed on day 0 (pre treatment), 7th and 14th (post treatment). The necropsy was performed on all animals at the termination of the study. The test compound applied at the dose level of 2000 mg/kg b.wt in Wistar albino rats did not show any mortality as well as clinical signs of toxicity throughout the observation period of 14 days. The necropsy was conducted on all the animals at the end of observation period did not show any gross pathological changes.  

Confirmatory Test:

After 72 hrs, confirmatory test was conducted in same species of animals to confirm result obtained from the limit test (OECD-402 guidelines for testing of chemicals). Ten healthy Wistar albino rats of both sex (ranging b.wt 200±20 gm) were selected for the study after acclimatization. Approximate 10 percent back skin of total body surface area was prepared 24 hrs prior to application of test compound. The test chemical was applied dermally at the dose level of 2000 mg/kg b.wt for each animal. The treated animals were observed for clinical signs of intoxication and mortality at different time interval for a period of 14 days. The body weight of each rat was observed on day 0 (pre treatment), 7th and 14th (post treatment). The necropsy was performed on all animals at termination of the study. No mortality was recorded after administration of test compound at the dose level of 2000 mg/kg b.wt. The test compound did not elicit any clinical signs of toxicity during the entire observation period. No skin reaction was observed after 24th hrs. of patch removal. The body weight of each animal recorded on day 0, 7th and 14th showed normal increase in weight.

Based on the results obtained from present investigation, it can be concluded that the LD50 value was considered to be >2000 mg/kg bw, when Wistar albino rats treated with the test chemical applied dermally on the shaven back skin. Hence, the given test chemical is acutely non toxic.