Registration Dossier

Administrative data

Endpoint:
skin irritation: in vivo
Type of information:
experimental study
Adequacy of study:
key study
Study period:
The study was performed between 18 May 2010 and 21 May 2010
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
Study conducted in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or minor methodological deficiencies, which do not affect the quality of the relevant results. The study report was conclusive, done to a valid guideline and the study was conducted under GLP conditions.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2010
Report Date:
2010

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 404 (Acute Dermal Irritation / Corrosion)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method B.4 (Acute Toxicity: Dermal Irritation / Corrosion)
Deviations:
no
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Sponsor's identification: β-Alanine
Description : white crystalline solid
Batch number : 102657
Date received : 20 April 2010
Expiry date : 20 April 2013
Storage conditions: room temperature in the dark over silica gel

Test animals

Species:
rabbit
Strain:
New Zealand White
Details on test animals and environmental conditions:
Animals and Animal Husbandry
Two New Zealand White rabbits were supplied by Harlan Laboratories U.K. Ltd., Loughborough, UK. At the start of the study the animals weighed 2.09 or 2.16 kg and were twelve to twenty weeks old. After an acclimatisation period of at least five days each animal was given a number unique within the study which was written with a black indelible marker-pen on the inner surface of the ear and on the cage label.

The animals were individually housed in suspended cages. Free access to mains drinking water and food (2030 Teklad Global Rabbit diet supplied by Harlan Laboratories U.K. Ltd., Oxon, UK) was allowed throughout the study. The diet and drinking water were considered not to contain any contaminantof a level that might have affected the purpose or integrity of the study.

The temperature and relative humidity were set to achieve limits of 17 to 23°C and 30 to 70% respectively. Any occasional deviations from these targets were considered not to have affected the purpose or integrity of the study. The rate of air exchange was at least fifteen changes per hour and the lighting was controlled by a time switch to give twelve hours continuous light (06:00 to 18:00) and twelve hours darkness.

The animals were provided with environmental enrichment items which were considered not to contain any contaminant of a level that might have affected the purpose or integrity of the study.

Test system

Type of coverage:
semiocclusive
Preparation of test site:
other: clipped
Vehicle:
other: test material was moistened with 0.5 mL of distilled water.
Controls:
no
Amount / concentration applied:
TEST MATERIAL
- Amount(s) applied:
0.5 g

- Concentration:
Not applicable.

VEHICLE
- Amount(s) applied:
0.5g of test material was moistened with 0.5 ml of distilled water.

- Concentration:
Not applicable.

- Lot/batch no.:
Not given in study report.
Duration of treatment / exposure:
4 hours
Observation period:
72 hours
Number of animals:
2
Details on study design:
Preparation of Test Material
For the purpose of the study the test material was used as supplied.
The absorption of the test material was not determined.

Measurement of pH
The pH of the test material was determined prior to commencement of the study and found to be as follows:
Preparation pH Measurement
immediately after 10 minutes after 20 minutes
10% w/w aqueous preparation
of the test material 6.8 6.1 6.4

Procedure
On the day before the test each of a group of two rabbits was clipped free of fur from the dorsal/flank area using veterinary clippers. Only animals with a healthy intact epidermis by gross observation were selected for the study.
On the day of the test a suitable test site was selected on the back of each rabbit. At each test site a quantity of 0.5 g of the test material, moistened sufficiently with 0.5 ml of distilled water to achieve a dry paste, was introduced under a 2.5 cm x 2.5 cm cotton gauze patch. The patch was secured in position with a strip of surgical adhesive tape. To prevent the animals interfering with the patches, the trunk of each rabbit was wrapped in an elasticated corset and the animals were returned to their cages for the duration of the exposure period.
Four hours after application the corset and patches were removed from each animal and any residual test material removed by gentle swabbing with cotton wool soaked in distilled water.
Immediately following removal of the patches and approximately 1, 24, 48 and 72 hours later, the test sites were examined for evidence of primary irritation and scored according to the following scale:

Results and discussion

In vivo

Resultsopen allclose all
Irritation parameter:
other: Erythema/Eschar Formation
Basis:
animal: 69223 Male
Time point:
other: 24, 48 and 72 hours
Score:
0
Max. score:
4
Reversibility:
other: No evidence of skin irritation
Irritation parameter:
other: Erythema/Eschar Formation
Basis:
animal: 69224 male
Time point:
other: 24, 48 and 72 hours
Score:
0
Max. score:
4
Reversibility:
other: No evidence of skin irritation
Irritation parameter:
other: Oedema Formation
Basis:
animal: 69223 male
Time point:
other: 24, 48 and 72 hours
Score:
0
Max. score:
4
Reversibility:
other: No evidence of skin irritation
Irritation parameter:
other: Oedema Formation
Basis:
animal: 69224 male
Time point:
other: 24, 48 and 72 hours
Score:
0
Max. score:
4
Reversibility:
other: No evidence of skin irritation
Irritant / corrosive response data:
The individual scores for erythema/eschar and oedema are given in remarks on results including tables and figures.
No evidence of skin irritation was noted during the study.

Any other information on results incl. tables

The individual scores for erythema/eschar and oedema are given in the folowing table.

Individual Skin Reactions

Skin Reaction

Observation Time
(following patch removal)

Individual Scores – Rabbit Number and Sex

Total

69223Male

69224Male

Erythema/Eschar Formation

Immediately

0

0

(0 )

1 Hour

0

0

( 0 )

24 Hours

0

0

0

48 Hours

0

0

( 0 )

72 Hours

0

0

0

Oedema Formation

Immediately

0

0

( 0 )

1 Hour

0

0

( 0 )

24 Hours

0

0

0

48 Hours

0

0

( 0 )

72 Hours

0

0

0

Sum of 24 and 72-HourReadings(S)      :          0

Primary Irritation Index (S/4)                   :          0/4 = 0.0

Classification                                        :          NON-IRRITANT


(   ) = Total values not used for calculation of primary irritation index

The test material produced a Erythema score and Oedema score of 0.0 and was classified as NON-IRRITANT to rabbit skin according to the Draize classification scheme. No corrosive effects were noted.

Bodyweight

Individual bodyweights and bodyweight changes are given in Table 2.

Both animals showed expected gain in bodyweight during the study.

Table 2              Individual Bodyweights and Bodyweight Changes

Rabbit Number
and Sex

Individual Bodyweight (kg)

Bodyweight Change (kg)

Day 0

Day 3

69223Male

2.16

2.22

0.06

69224Male

2.09

2.19

0.10

 Interpretation of Results

Calculation of Primary Irritation Index and Grading of Irritancy Potential Using the Draize Scheme

The scores for erythema and oedema at the 24 and 72-Hour readings were totalled for the two test rabbits (8 values) and this total was divided by four to give the primary irritation index of the test material. The test material was classified according to the following scheme devised by Draize J H (1959) "Dermal Toxicity" In: Appraisal of the Safety of Chemicals in Foods, Drugs and Cosmetics. Association of Food and Drug Officials of the United States, Austin, Texas, p.46 -59:

Primary Irritation Index

Classification of Irritancy

     0

Non-irritant

> 0 to 2

Mild irritant

> 2 to 5

Moderate irritant

> 5 to 8

Severe irritant

If irreversible alteration of the dermal tissue is noted in any rabbit, as judged by the Study Director, which include ulceration and clear necrosis or signs of scar tissue, the test material is classified as corrosive to rabbit skin. Classification according to Draize may, therefore, not be applicable.


Applicant's summary and conclusion

Interpretation of results:
not irritating
Remarks:
Migrated information Criteria used for interpretation of results: other: DSD and CLP classification criteria
Conclusions:
The test material produced is not irritanting to the skin of the rabbit according to the Draize classification scheme. No corrosive effects were noted.
Executive summary:

Introduction. 

The study was performed to assess the irritancy potential of the test material to the skin of the New Zealand White rabbit. The method was designed to meet the requirements of the following:

OECD Guidelines for the Testing of Chemicals No. 404 “Acute Dermal Irritation/Corrosion” (adopted24 April 2002)

Method B4 Acute Toxicity (Skin Irritation) of CommissionRegulation (EC) No. 440/2008

Results. 

A single 4-Hour, semi-occluded application of the test material to the intact skin of two rabbits produced no evidence of skin irritation. 

Conclusion. 

The test material produced is not irritanting to the skin of the rabbit according to the Draize classification scheme. No corrosive effects were noted.