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Toxicological information

Eye irritation

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Administrative data

Endpoint:
eye irritation: in vivo
Type of information:
experimental study
Adequacy of study:
key study
Study period:
February 22 - 25, 2006
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: The study followed eastablished OECD guidelines and was conducted under GLP various assurances.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2006

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 405 (Acute Eye Irritation / Corrosion)
Deviations:
no
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
The test substance, identified as 2,2,4,4-Tetramethyl-1,3-cyclobutanediol, Lot #X29601-54-5, consisted of white crystals and was stored at room
temperature. Prior to use, the test substance was ground in a coffee mill. Purity was 99.6%.

Test animals / tissue source

Species:
rabbit
Strain:
New Zealand White
Details on test animals or tissues and environmental conditions:
Number of Animals: 6
Sex: Male
Species/Strain: Rabbit/New Zealand albino.
Age: Young adult.
Source: Received from Robinson Services, Inc. Clemmons, NC on February 8, 2006.

Housing: The animals were singly housed in suspended stainless steel caging witb mesh floors. Litter paper was placed beneath the cage and was changed at least three times per week.
Animal Room Temperature Range: 2l-23°C
Photoperiod: 12-hour light/dark cycle
Acclimation Period: 14 days
Food: Pelleted Purina Rabbit Chow #5326
Water: Filtered tap water was supplied ad-libitum by an automatic water dispensing system.

Test system

Vehicle:
unchanged (no vehicle)
Controls:
yes, concurrent no treatment
Amount / concentration applied:
0.06 grams
Duration of treatment / exposure:
72 hours
Observation period (in vivo):
1, 24, 48, 72 hours
Number of animals or in vitro replicates:
6 (3 rinsed, 3 not rinsed)
Details on study design:
Prior to test initiation, both eyes of a group of animals were examined using a white light source and a fluorescein dye procedure. One drop of 2%
ophthalmic fluorescein sodium was instilled into both eyes of each rabbit. The eyes were rinsed with physiological saline (0.9% NaCI) approximately 30 seconds after instillation of the fluorescein and then evaluated for corneal damage using an ultraviolet light source. Prior to instillation, the eyes were re-examined and scored for abnormalities. Six healthy animals without pre-existing ocular irritation were selected for test. Prior to instillation, 1-2 drops of ocular anesthetic (Tetracaine Hydrochloride Ophthalmic Solution, (0.5%) were placed into both the treated and control eye of each
animal. Prior to use, the test substance was ground in a coffee mill and 0.06 grams of the ground test substance (equiv to 0.1 ml) was then instilled into the
conjunctival sac of the right eye of each rabbit by pulling the lower lid away from the eyeball. The upper and lower lids were then gently held together for about one second before releasing to minimize loss of the test substance. The other eye of each rabbit remained untreated with the test
substance and served as a control. The treated eyes of three rabbits were rinsed with approximately 30 ml of physiological saline (0.9% NaCI) approximately 30 seconds after instillation of the test substance. The eyes of the remaining three animals were not rinsed. The rabbits were then
returned to their designated cages. Ocular irritation was evaluated using a high-intensity white light (Mag Lite) in accordance with Draize et .al at I,
24, 48, and 72 hours post-instillation. The fluorescein dye evaluation procedure was used at 24 hours and as needed at subsequent scoring
intervals to evaluate the extent of corneal damage or to verifY reversal of effects. Individual scores were recorded for each animal. In addition to
observations of the cornea, iris, and conjunctivae, any other observed lesions were noted. The average score for all rabbits at each scoring period
was calculated to aid in data interpretation. The animals were observed for signs of gross toxicity and behavioral changes at least once daily
during the test period. Observations included gross evaluation of skin and fur, eyes and mucous membranes, respiratory, circulatory, autonomic
and central nervous systems, somatomotor activity and behavior pattern. Particular attention was directed to observation of tremors, convulsions,
salivation, diarrhea, and coma.

Results and discussion

In vivo

Resultsopen allclose all
Irritation parameter:
maximum mean total score (MMTS)
Basis:
mean
Score:
4
Max. score:
4
Reversibility:
fully reversible within: 48 hours
Remarks on result:
other: rinsed
Irritation parameter:
maximum mean total score (MMTS)
Basis:
mean
Score:
18
Max. score:
24
Reversibility:
fully reversible within: 72 hours
Remarks on result:
other: unrinsed
Irritant / corrosive response data:
Rinsed Eyes
There was no corneal opacity or iritis observed in any treated rinsed eyes during this study. For the first 24 hours after test substance instillation, all three treated rinsed eyes exhibited conjunctivitis. The overall incidence and severity of irritation decreased gradually. All animals were tree of ocular irritation by 48-hours.

Unrinsed Eyes
Within 24 hours after test substance instillation, all three treated unrinsed eyes exhibited corneal opacity, iritis, and conjunctivitis. The overall
incidence and severity of irritation decreased gradually. All animals were free of ocular irritation by 72 hours.

The Maximum Mean Total Score of 2,2,4,4-Tetramethyl-1 ,3-cyclobutanediol is 18.0 and 4.0 for the unrinsed and rinsed eye, respectively.

Any other information on results incl. tables

Scores from Unrinsed Eyes

 

Rabbit No.: 16142 (Male)

Rabbit No.: 16143 (Male)

Rabbit No.: 16144 (Male)

 

Hours

Hours

Hours

 

1

24

48

72

1

24

48

72

1

24

48

72

Corneal Opacity

0

1

1

0

0

1

0

0

1

1

0

0

 

 

 

 

 

 

 

 

 

 

 

 

 

Iris

1

1

0

0

1

1

0

0

1

1

0

0

 

 

 

 

 

 

 

 

 

 

 

 

 

Conjunctiva

 

 

 

 

 

 

 

 

 

 

 

 

Redness

3

2

2

0

3

2

1

0

3

2

1

0

Chemosis

1

0

0

0

1

0

0

0

2

1

0

0

Applicant's summary and conclusion

Conclusions:
Under the conditions of this study, 2,2,4,4-Tetramethyl-1 ,3-cyclobutanediol is classified as mildly and minimally irritating to the unrinsed and
rinsed eye, respectively.
Executive summary:

A primary eye irritation test was conducted with rabbits to determine the potential for 2,2,4,4 -tetramethyl-1,3 -cyclobutanediol to produce irritation from a single instillation via the ocular route. A tenth of a milliliter (0.06 g) of the ground test substance was instilled into the right eye of six healthy rabbits. The treated eyes of three rabbits were rinsed with physiological saline after instillation. The eyes of the remaining three rabbits were not rinsed. The left eye remained untreated and served as a control. Ocular inritation was evaluated by the method of Draize et .al. In the rinsed eyes there was no corneal opacity or iritis observed during this study. For the first 24 hours after test substance instillation, all three rinsed treated eyes exhibited conjunctivitis. The overall incidence and severity of irritation decreased gradually. All animals were free of ocular irritation by 48 -hours. In the unrinsed eyes within 24 hours after test substimce instillation, all three treated eyes exhibited corneal opacity, iritis, and conjunctivitis. The overall incidence and severity of irritation decreased gradually thereafter. All animals were free of ocular irritation by 72 hours. Under the conditions of this study, the test substance is classified as mildly and minimally irritating to the unrinsed and rinsed eye, respectively. All animals appeared active and healthy. Apart from the eye irritation noted, there were no other signs of gross toxicity, adverrse pharmacologic effects or abnormal behavior.