2,2-bis(hydroxymethyl)propionic acid

Eye irritation

Administrative data

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

25 May to 21 June 1999

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Proprietary GLP guideline-compliant study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1999

Report Date:

1999

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Test guideline 2

Qualifier:

according to

Guideline:

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

GLP compliance:

yes

Remarks:

OECD

Test material

Reference

Name:

Unnamed

Type:

Constituent

Details on test material:

2,2-Bis(hydroxymethyl)propanoic acid, CAS number 4767-03-7, described as a white solid. The substance number was 98/485-1, and the batch number was SE 8069. The purity was confirmed to be 99.4 g/100g by Potentiometric titration. The test material was stored at room temperature. The stability of the test material over the study period was proven by reanalysis. The test substance was also described as homogeneous by visual inspection.

Test animals / tissue source

Species:

rabbit

Strain:

Himalayan

Details on test animals or tissues and environmental conditions:

The animals were young adult male Himalayan Chbb: HM (outbred strain) rabbits, obtained from Boehringer Ingelheim Pharma KG. The rabbits were acclimatised for at least 1 week. The rabbits weighed 2.42-2.66 kg.
The animals were housed in fully air-conditioned rooms . Central air-conditioning guaranteed a range of 20 - 24°C for temperature and of 30 - 70% for relative humidity. Light was provided on a 12 hour light/dark cycle. The rabbits were singly housed in stainless steel wire mesh cages with grating, with a floor area of 3000 cm². Bedding was not provided in the cages, wood shavings were placed in the waste trays. Individuals were identified by ear tattoo. The rabbits were provided with approximately 250 ml tap water per animal per day, and approximately 130 g food per animal per day (Kliba-Labordiaet, Switzerland).

Test system

Vehicle:

unchanged (no vehicle)

Controls:

yes, concurrent no treatment

Amount / concentration applied:

0.1 ml bulk volume (approximately 33g of the comminuted test substance).

Duration of treatment / exposure:

The test substance was applied in a single dose to the conjunctival sac of the right eyelid, the substance was washed out with tap water about 24 hours after application (before the 24 h reading).

Observation period (in vivo):

14 days: readings were taken at 1 h, 24 h, 48 h, 72 h, 7 d and 14 d after application.

Number of animals or in vitro replicates:

3 male rabbits

Details on study design:

The test substance was applied in a single dose to the conjunctival sac of the right eyelid, the substance was washed out with tap water about 24 hours after application (before the 24 h reading). The left eye remained untreated to serve as a negative control.
Checks for dead or moribund animals were made twice each workday and once on weekends and public holidays.
Ocular lesions were assessed according to the scoring system defined in the OECD test guideline 405. The mean values were calculated according to 93/21/EEC (for calculation of the means of corneal opacity, iris, redness and swelling of the conjunctiva only the readings of 24, 48 and 72 hours are used).

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

cornea opacity score

Basis:

mean

Time point:

other: 24, 48 & 72 hours

Score:

0.78

Max. score:

1

Reversibility:

fully reversible within: 14 days

Results 2

Irritation parameter:

iris score

Basis:

mean

Time point:

other: 24, 48 & 72 hours

Score:

0.67

Max. score:

1

Reversibility:

fully reversible within: 14 days

Results 3

Irritation parameter:

conjunctivae score

Remarks:

redness

Basis:

mean

Time point:

other: 24, 48 & 72 hours

Score:

2.56

Max. score:

3

Reversibility:

fully reversible within: 14 days

Results 4

Irritation parameter:

chemosis score

Basis:

mean

Time point:

other: 24, 48 & 72 hours

Score:

2

Max. score:

3

Reversibility:

fully reversible within: 14 days

Irritant / corrosive response data:

1 rabbit showed suppuration at the 24, 48 and 72 hour readings. At the 48 and 72 hour readings this rabbit had also developed a contracted pupil and discharge of blood. A second rabbit displayed suppuration, contracted pupil and discharge of blood at the 48 and 72 h readings. These symptoms had disappeared by the 7 day reading. Data are presented in Table 1.

Other effects:

No other effects reported.

Any other information on results incl. tables

Irritant response data.

Reading	Rabbit	Cornea		Iris	Conjunctiva			Symptoms
		Opacity	Area		Redness	Chemosis	Discharge
1 h	1	0	0	0	1	2	3
	2	0	0	0	1	2	2
	3	0	0	0	2	2	3
24 h	1	1	1	0	2	2	3
	2	1	1	1	2	3	3
	3	1	1	1	3	2	3	S
48 h	1	0	0	0	2	1	2
	2	1	1	1	3	3	3	S, PC, DB
	3	1	1	1	3	2	3	S, PC, DB
72 h	1	0	0	0	2	1	2
	2	1	3	1	3	2	3	S, PC, DB
	3	1	3	1	3	2	3	S, PC, DB
7 d	1	0	0	0	1	0	1
	2	0	0	0	2	1	0
	3	0	0	1	2	1	0
14 d	1	0	0	0	0	0	0
	2	0	0	0	0	0	0
	3	0	0	0	0	0	0
Mean	1	0.33		0.00	2.00	1.33
	2	1.00		1.00	2.67	2.67
	3	1.00		1.00	3.00	2.00
Mean		0.78		0.67	2.56	2.00

Key

S = suppuration

PC = pupil contracted

DB = discharge of blood

Applicant's summary and conclusion

Interpretation of results:

irritating

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The authors concluded that the results obtained indicate that 2,2-Bis(hydroxymethyl)propanoic acid is irritating to the eye.

Executive summary:

The eye irritant potential of 2,2 -Bis(hydroxymethyl)propanoic acid was assessed in 3 Himalayan rabbits. The test substance was applied to the right eye in a single application of 0.1 ml bulk volume, and washed out with tap water 24 hours later. Irritant reactions were scored at 24 h, 48 h, 72 h, 7 d and 14 d after application. The average score (24 to 72 hours) for irritation was calculated to be 0.78 for corneal opacity, 0.67 for iris, 2.56 for conjunctival redness and 2.00 for chemosis. The findings were reversible in all animals within 14 days after application. Symptoms observed included suppuration, contracted pupil and discharge of blood. The authors concluded that the results obtained indicate that 2,2-Bis(hydroxymethyl)propanoic acid is irritating to the eye.