[1,2,4]Triazolo[1,5-a]pyrimidin-2-amine, 5,7-dimethoxy-

Eye irritation

Administrative data

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

January 27 - 30, 2005

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study conducted to GLP 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.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2005

Report date:

2005

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.2400 (Acute Eye Irritation)

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

5,7-dimethoxy-[1,2,4]triazolo[1,5-a]pyrimidin-2-amine

EC Number:

603-562-0

Cas Number:

13223-43-3

Molecular formula:

C7H9N5O2

IUPAC Name:

5,7-dimethoxy-[1,2,4]triazolo[1,5-a]pyrimidin-2-amine

Details on test material:

- Name of test material (as cited in study report): ADTP
- Physical state: off-white solid
- Analytical purity: 99.8%
- Lot/batch No.: 041206-5D
- Expiration date of the lot/batch: n/a
- Stability under test conditions: Test substance was expected to be stable for the duration of testing.
- Storage condition of test material: room temperature
- pH: 7-8 (by wetted pH paper)

Test animals / tissue source

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Source: Received from Robinson Services, Inc. Clemmons, NC on December 29, 2004.
- Age at study initiation: Young adult.
- Weight at study initiation: not reported
- Housing: The animals were singly housed in suspended stainless steel caging with mesh floors which conform to the size recommendations in the most recent Guide, for the Care and Use of Laboratory Animals DHEW (NIH). Litter paper was placed beneath the cage and was changed at least three times per week.
- Diet (e.g. ad libitum): Purina Certified Rabbit Diet PMI #5322
- Water (e.g. ad libitum): Filtered tap water was supplied ad-libitum by an automatic water dispensing system.
- Acclimation period: 8 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20-22°C
- Humidity (%): 45-54 % RH
- Photoperiod (hrs dark / hrs light): 12-hour light/dark cycle

Test system

Vehicle:

unchanged (no vehicle)

Remarks:

Prior to use, the test substance was ground to a powder with a mortar and pestle.

Controls:

yes, concurrent no treatment

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.05 g

Duration of treatment / exposure:

One-tenth of a milliliter (0.05 grams) of the test substance was 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.

Observation period (in vivo):

1, 24, 48, and 72 hours post-instillation

Number of animals or in vitro replicates:

3 (2 males and 1 female)

Details on study design:

SCORING SYSTEM: Ocular irritation was evaluated with the Draize scoring system

TOOL USED TO ASSESS SCORE: Ocular irritation was evaluated using a high-intensity white light (Mag Lite).
The fluorescein dye evaluation procedure was used at 24 hours to verify the absence of corneal damage. One drop of 2% ophthalmic fluorescein sodium was instilled into both eyes of each rabbit. The eyes were rinsed with physiological saline (0.9% NaCl) approximately 30 seconds after instillation of the fluorescein. Using an ultraviolet light source, the eyes were checked for gross abnormalities according to the "Seale for Scoring Ocular Lesions"

TABLE 2: SCALE FOR SCORING OCULAR LESIONS

1. Cornea
A. Opacity-degree of density (area most dense taken for reading)

No Opacity 0
Scattered or diffuse area, details of iris clearly visible 1
Easily discernible translucent areas, details of iris slightly obscured 2
Opalescent areas, no details of iris visible, size of pupil barely discernible 3
Opaque, iris invisible 4

B. Area of cornea involved

One quarter (or less) but not zero 1
Greater than one quarter, but less than half 2
Greater than half, but less than three quarters 3
Greater than three quarters, up to whole area 4

A X B X 5 Total Maximum = 80

2. Iris
A. Values

Normal 0
Folds above normal, congestion, swelling, circumcorneal injection
(any or all of these or combination of any thereof) iris still reacting
to light (sluggish reaction is positive) 1
No reaction to light, hemorrhage, gross destruction (any or all of these) 2

A X 5 Total Maximum = 10

3. Conjunctivae
A. Redness (refers to palpebral and bulbar conjunctivae excluding cornea and iris)

Vessels normal 0
Vessels definitely injected above normal 1
More diffuse, deeper crimson red, individual vessels not easily discernible 2
Diffuse beefy red 3

B. Chemosis

No swelling 0
Any swelling above normal (includes nictitating membrane) 1
Obvious swelling with partial eversion of lids 2
Swelling with lids about half-closed 3
Swelling with lids about half-closed to completely closed 4

C. Discharge

No discharge 0
Any amount different from normal (does not include small amounts
observed in inner canthus of normal animals) 1
Discharge with moistening of the lids and hairs just adjacent to lids 2
Discharge with moistening of the lids and hairs,
and considerable area around the eye 3

Score (A + B + C) X 2 Total Maximum = 20

Total Maximum Score: 110 represents the sum of all scores obtained for the cornea, iris and conjunctivae

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

cornea opacity score

Basis:

mean

Time point:

other: 24, 48 & 72 hours

Score:

0

Max. score:

0

Reversibility:

other: no effects seen

Results 2

Irritation parameter:

iris score

Basis:

mean

Time point:

other: 24, 48 & 72 hours

Score:

0.11

Max. score:

1

Reversibility:

fully reversible within: 48 hours

Results 3

Irritation parameter:

conjunctivae score

Basis:

mean

Time point:

other: 24, 48 & 72 hours

Score:

0.33

Max. score:

1

Reversibility:

fully reversible within: 48 hours

Results 4

Irritation parameter:

chemosis score

Basis:

mean

Time point:

other: 24, 48 & 72 hours

Score:

0

Max. score:

1

Reversibility:

other: no effects seen

Remarks on result:

other: A score of 1 was recorded for two animals at the 1 hour observation.

Irritant / corrosive response data:

There was no corneal opacity observed in any treated eye during this study. At one and 24 hours after test substance instillation, one treated eye exhibited iritis and all three animals exhibited signs consistent with conjunctivitis and included redness, edema (chemosis), and discharge, All animals were free of ocular irritation by 48 hours.

Other effects:

All animals appeared active and healthy. Apart from the eye irritation noted, there were no other signs of gross toxicity, adverse clinical signs, or abnormal behavior.

Any other information on results incl. tables

TABLE 1: INDIVIDUAL SCORES FOR OCULAR IRRITATION

	Rabbit No.: 13622 (Male)				Rabbit No.: 13623 (Female)				Rabbit No.: 13624 (Male)
	Hours				Hours				Hours
	1	24	48	72	1	24	48	72	1	24	48	72
I. Cornea
A. Opacity	0	0^3	0	0	0	0^3	0	0	0	0^3	0	0
B. Area	4	4	4	4	4	4	4	4	4	4	4	4
A x B x 5	0	0	0	0	0	0	0	0	0	0	0	0
II. Iris
A. Values	1	1	0	0	0	0	0	0	0	0	0	0
A x 5	5	5	0	0	0	0	0	0	0	0	0	0
III. Conjunctivae
A. Redness	2	1	0	0	2	1	0	0	2	1	0	0
B. Chemosis	1	0	0	0	0	0	0	0	1	0	0	0
C. Discharge	1	0	0	0	1	0	0	0	2	1	0	0
A + B+ C x 2	8	2	0	0	6	2	0	0	10	4	0	0
Total	13	7	0	0	6	2	0	0	10	4	0	0

³ 2% ophthalmic fluorescein sodium used to verify the absence of corneal opacity

Applicant's summary and conclusion

Interpretation of results:

not irritating

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

Under the conditions of this study, the test substance caused iritis and conjunctival irritation which cleared by 48 hours. It does not meet the criteria under either CLP or DSD to be classified as an eye irritant.

Executive summary:

A primary eye irritation test was conducted in accordance with EPA OPPTS 870.2400 (Acute Eye Irritation) with rabbits to determine the potential for ADTP to produce irritation from a single instillation via the ocular route. Under the conditions of this study, the test substance caused iritis and conjunctival irritation which cleared by 48 hours.

One-tenth of a milliliter (0.05 grams) of the test substance was instilled into the right eye of three healthy rabbits. The left eye remained untreated and served as a control. Ocular irritation was evaluated by the method of Draize et al.

There was no corneal opacity observed in any treated eye during this study. At one and 24 hours after test substance instillation, one treated eye exhibited iritis and all three animals exhibited signs consistent with conjunctivitis and included redness, edema (chemosis), and discharge. All animals were free of ocular irritation by 48 hours.