Nicotinamide

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Report date:

2000

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)

Remarks:

Safepharm Laboratories Ltd.

Test material

Test material information

Constituent 1

Reference substance name:

Nicotinamide

EC Number:

202-713-4

EC Name:

Nicotinamide

Cas Number:

98-92-0

Molecular formula:

C6H6N2O

IUPAC Name:

nicotinamide

Test material form:

solid: crystalline

Details on test material:

- Name of test material: Nicotinamide

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Age at study initiation: Twelve to sixteen weeks
- Weight at study initiation: 2.61 to 2.96 kg
- Housing: The animals were individually housed in suspended metal cages
- Diet: Ad libitum
- Water: Ad libitum
- Acclimation period: Minimum acclimatisation period of five days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 17 to 23
- Humidity (%): 30 -70 (any occasional deviations from these targets were considered not to have affected the purpose or integrity of the study)
- Air changes (per hr): Fifteen changes per hour
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES:
- From: 05 April 2000
- To: 13 April 2000

Test system

Type of coverage:

semiocclusive

Preparation of test site:

clipped

Vehicle:

water

Controls:

no

Amount / concentration applied:

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

VEHICLE
- Amount applied: 0.5 ml

Duration of treatment / exposure:

4 hour exposure

Observation period:

Approximately one hour following the removal of the patches, and 24, 48 and 72 hours later

Number of animals:

1 Male, 2 Females

Details on study design:

TEST SITE
- Area of exposure: 2.5 cm x 2.5 cm
- Type of wrap if used: Cotton gauze patch secured in position with a strip of surgical adhesive tape (BLENDERM: approximate size 2.5 cm x 4.0 cm). To prevent the animals interfering with the patches, the trunk of each rabbit was wrapped in an elasticated corset (TUBIGRIP).

REMOVAL OF TEST SUBSTANCE
- Washing (if done): Residual test material was removed by gentle swabbing with cotton wool soaked in distilled water.
- Time after start of exposure: 4 hours

SCORING SYSTEM:
- Draize J H, (1977) "Dermal and Eye Toxicity Tests" In: Principles and Procedures for Evaluating the Toxicity of Household Substances, National Academy of Sciences, Washington DC p.31.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

primary dermal irritation index (PDII)

Basis:

mean

Time point:

other: 24 and 72 hours

Score:

0

Max. score:

0

Reversibility:

other: Not applicable

Results 2

Irritation parameter:

erythema score

Basis:

mean

Time point:

other: 24, 48 and 72 hours

Score:

0

Max. score:

0

Reversibility:

other: Not applicable

Results 3

Irritation parameter:

edema score

Basis:

mean

Time point:

other: 24, 48 and 72 hours

Score:

0

Max. score:

0

Reversibility:

other: Not applicable

Irritant / corrosive response data:

See table 1 below.

Any other information on results incl. tables

Table 1: Individual irritation scores

		Individual scores - rabbit number and sex (body weight kg)
Skin reaction	Observation time (hours)	133 Male (2.96)	174 Female (2.62)	63 Female (2.61)	Total
Erythema/eschar formation	1	0	0	0	0
	24	0	0	0	0
	72	0	0	0	0
	48	0	0	0	0
Oedema formation	1	0	0	0	0
	24	0	0	0	0
	48	0	0	0	0
	72	0	0	0	0

Applicant's summary and conclusion

Interpretation of results:

not irritating

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The test material produced a primary irritation index of 0.0 and was classified as non-irritant to rabbit skin according to the Draize classification scheme. No corrosive effects were noted.

Executive summary:

A study was performed to assess the irritancy potential of the test material to the skin of the New Zealand White rabbit. The method used followed the recommendations of EU Method B.4 and OECD Guideline 404 (Acute Dermal Irritation / Corrosion). A single 4-hour, semi-occluded application of the test material to the intact skin of three rabbits produced no evidence of skin irritation. The test material produced a primary irritation index of 0.0 and was classified as nonirritant to rabbit skin according to the Draize classification scheme. No corrosive effects were noted.