β-alanine

Eye irritation

Administrative data

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

The study was performed between 24 May 2010 and 04 June 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 guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

EU Method B.5 (Acute Toxicity: Eye Irritation / Corrosion)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

β-alanine

EC Number:

203-536-5

EC Name:

β-alanine

Cas Number:

107-95-9

Molecular formula:

C3H7NO2

IUPAC Name:

β-alanine

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 / tissue source

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues 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 2.30 or 2.59 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

Vehicle:

unchanged (no vehicle)

Controls:

other: EXAMPLE: The left eye remained untreated and was used for control purposes.

Amount / concentration applied:

TEST MATERIAL

- Amount(s) applied (volume or weight with unit):
A volume of 0.1 mL of the test material was placed into the conjunctival sac of the right eye, formed by gently pulling the lower lid away from the eyeball.

- Concentration:
Not applicable

VEHICLE

- Amount(s) applied:
Not applicable

- Concentration:
Not applicable

- Lot/batch no.:
Not applicable

- Purity:
Not reported

Duration of treatment / exposure:

72 hours

Observation period (in vivo):

Approximately 1 hour and 24, 48 and 72 hours following treatment

Number of animals or in vitro replicates:

2 animals were tested in total. (After consideration of the ocular responses produced in the first treated animal, an additional animal was treated)

Details on study design:

Procedure
Immediately before the start of the test, both eyes of the provisionally selected test rabbits were examined for evidence of ocular irritation or defect
with the aid of a light source from a standard ophthalmoscope. Only animals free of ocular damage were used.
Initially, a single rabbit was treated. A volume of 0.1 mL of the test material, which was found to weigh approximately 91 mg (as measured by gently
compacting the required volume into an adapted syringe) was placed into the conjunctival sac of the right eye, formed by gently pulling the lower lid
away from the eyeball. The upper and lower eyelids were held together for about one second immediately after treatment, to prevent loss of the test material, and then released. The left eye remained untreated and was used for control purposes. Immediately after administration of the test material, an assessment of the initial pain reaction was made according to the six point scale shown in Appendix 1.
After consideration of the ocular responses produced in the first treated animal, a second animal was treated.
Assessment of ocular damage/irritation was made approximately 1 hour and 24, 48 and 72 hours following treatment, according to the numerical
evaluation given in Appendix 2, (from 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.48 to 49).
Any other ocular effects were also noted. Examination of the eye was facilitated by the use of the light sourcefrom a standard ophthalmoscope.

Any clinical signs of toxicity, if present, were also recorded.

Individual body weights were recorded on Day 0 (the day of dosing) and at the end of the observation period.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

cornea opacity score

Basis:

animal: 69235 male

Time point:

other: 24, 48 and 72 hours

Score:

0

Max. score:

4

Reversibility:

other: No effects observed

Results 2

Irritation parameter:

cornea opacity score

Basis:

animal: 69278 male

Time point:

other: 24, 48 and 72 hours

Score:

0

Max. score:

4

Reversibility:

other: No effects observed

Results 3

Irritation parameter:

iris score

Basis:

animal: 69278 male

Time point:

other: 24, 48 and 72 hours

Score:

0

Max. score:

2

Reversibility:

other: No effects observed

Results 4

Irritation parameter:

iris score

Basis:

animal: 69235 male

Time point:

other: 24, 48 and 72 hours

Score:

0

Max. score:

2

Reversibility:

other: No effects observed

Results 5

Irritation parameter:

conjunctivae score

Remarks:

redness

Basis:

animal: 69235 male

Time point:

other: 24, 48 and 72 hours

Score:

0.33

Max. score:

3

Reversibility:

fully reversible within: 48 hours

Remarks on result:

other: conjunctival redness was observed at 1 hour observation

Results 6

Irritation parameter:

conjunctivae score

Remarks:

redness

Basis:

animal: 69278 male

Time point:

other: 24, 48 and 72 hours

Score:

0.33

Max. score:

3

Reversibility:

fully reversible within: 48 hours

Remarks on result:

other: conjunctival redness was observed at 1 hour observation

Results 7

Irritation parameter:

chemosis score

Basis:

animal: 69235 male

Time point:

other: 24, 48 and 72 hours

Score:

0.33

Max. score:

4

Reversibility:

fully reversible within: 48 hours

Remarks on result:

other: conjunctival redness was observed at 1 hour observation

Results 8

Irritation parameter:

chemosis score

Basis:

animal: 69278 male

Time point:

other: 24, 48 and 72 hours

Score:

0

Max. score:

4

Reversibility:

fully reversible within: 48 hours

Remarks on result:

other: conjunctival redness was observed at 1 hour observation

Irritant / corrosive response data:

Ocular Reactions
Individual and group mean scores for ocular irritation are given in Table 1 and Table 2.
No corneal or iridial effects were noted during the study.
Moderate conjunctival irritation was noted in both treated eyes one hour after treatment with minimal conjunctival irritation noted at the 24-hour observation.
Both treated eyes appeared normal at the 48-hour observation.

Other effects:

Body weight
All animals showed expected gain in body weight during the study.

Any other information on results incl. tables

Interpretation of Results

The numerical values corresponding to each animal, tissue and observation time were recorded. The data relating to the conjunctivae were designated by the letters A (redness), B (chemosis) and C (discharge), those relating to the iris designated by the letter D and those relating to the cornea by the letters E (degree of opacity) and F (area of cornea involved). For each tissue the score was calculated as follows:

Score for conjunctivae =         (A + B + C) x 2
Score for iris                  =         D x 5
Score for cornea           =         (E x F) x 5

Using the numerical data obtained a modified version of the system (Modified Kay and Calandra Interpretation of Eye Irritation Test was used to classify the ocular irritancy potential of the test material. This was achieved by adding together the scores for the cornea, iris and conjunctivae for each time point for each rabbit. The group means of the total scores for each observation were calculated. The highest of these group means (the maximum group mean score) together with the persistence of the reactions enabled classification of the eye irritancy potential of the test material.

If evidence of irreversible ocular damage is noted, the test material will be classified as corrosive to the eye.

Table 1              IndividualScores and Individual Total Scoresfor Ocular Irritation

Rabbit Number and Sex	69235Male				69278Male
	IPR= 2				IPR = 2
Time After Treatment	1 Hour	24 Hours	48 Hours	72 Hours	1 Hour	24 Hours	48 Hours	72 Hours
CORNEA
E = Degree of Opacity	0	0	0	0	0	0	0	0
F = Area of Cornea Involved	0	0	0	0	0	0	0	0
Score (E x F) x 5	0	0	0	0	0	0	0	0
IRIS
D	0	0	0	0	0	0	0	0
Score (D x 5)	0	0	0	0	0	0	0	0
CONJUNCTIVAE
A = Redness	2	1	0	0	2	1	0	0
B = Chemosis	2	1	0	0	1	0	0	0
C = Discharge	1	0	0	0	1	0	0	0
Score (A + B + C) x 2	10	4	0	0	8	2	0	0
Total Score	10	4	0	0	8	2	0	0

IPR= Initial pain reaction

Table 2              Individual Total Scores and Group Mean Scoresfor Ocular Irritation

Rabbit Number and Sex	Individual Total Scores At:
	1 Hour	24 Hours	48 Hours	72 Hours
69235Male	10	4	0	0
69278Male	8	2	0	0
Group Total	18	6	0	0
Group Mean Score	9.0	3.0	0.0	0.0

 

However, the cornea and iris scores were=0 in both animals, the chemosis score was =0.33 in one animal and =0 in the second animals, and redness score was 0.33 in both animals at 24, 48, and 72 -hour observation period. On the basis of the results of the study, beta-alanine has not to be classified as irritating for eye according to DSD and CLP classification criteria.

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

Executive summary:

Introduction. 

The study was performed to assess the irritancy potential of the test material to the eye 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. 405 “Acute Eye Irritation/Corrosion” (adopted 24 April 2002)

Method B5 Acute Toxicity (Eye Irritation) of Commission Regulation (EC) No. 440/2008

Result. 

A single application of the test material to the non-irrigated eye of two rabbits produced moderate conjunctival irritation. Both treated eyes appeared normal at the 48-hour observation.

Conclusion. 

The test material produced a maximum group mean score of 9.0 and was classified as a minimal irritant (Class 3 on a 1 to 8 scale) to the rabbit eye according to a modified Kay and Calandra classification system However, the cornea and iris scores were=0 in both animals, the chemosis score was =0.33 in one animal and =0 in the second animals, and redness score was 0.33 in both animals. On the basis of the results of the study, beta-alanine has not to be classified as irritating for eye according to DSD and CLP classification criteria.