Pyridine, 2-methoxy-4-(trifluoromethyl)-

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 recognised guidelines and GLP.

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:

2-methoxy-4-(trifluoromethyl)pyridine

EC Number:

606-870-3

Cas Number:

219715-34-1

Molecular formula:

C7H6F3NO

IUPAC Name:

2-methoxy-4-(trifluoromethyl)pyridine

Details on test material:

- Name of test material (as cited in study report): M-TMP
- Physical state: colourless liquid
- Analytical purity: 99.7%
- Lot/batch No.: 041206-7D
- 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: 6-7 (by wetted pH paper)
- Solubility: Soluble in methanol, ethanol, and acetone.

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 January 19, 2005.
- Age at study initiation: Young adult.
- Housing: The animals were singly housed in suspended stainless steel caging with mesh floors which confoini 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%
- Photoperiod (hrs dark / hrs light): 12-hour light/dark cycle

Test system

Vehicle:

unchanged (no vehicle)

Controls:

other: The left eye of each rabbit remained untreated with the test substance and served as a control.

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): One-tenth of a milliliter

Duration of treatment / exposure:

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 males

Details on study design:

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

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

TOOL USED TO ASSESS SCORE: Ocular irritation was evaluated using a high-intensity white light (Mag Lite) at 1, 24, 48, and 72 hours post-instillation. Fluorescein dye was used at 24 hours to verify the absence of corneal damage. 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.

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

Max. score:

0

Reversibility:

other: no effects seen

Results 3

Irritation parameter:

conjunctivae score

Basis:

mean

Time point:

other: 24 hours

Score:

1

Max. score:

1

Reversibility:

fully reversible within: 72 hours

Results 4

Irritation parameter:

conjunctivae score

Basis:

mean

Time point:

other: 48 hours

Score:

0.33

Max. score:

1

Reversibility:

fully reversible within: 72 hours

Results 5

Irritation parameter:

conjunctivae score

Basis:

mean

Time point:

other: 72 hours

Score:

0

Max. score:

0

Reversibility:

fully reversible

Results 6

Irritation parameter:

chemosis score

Basis:

mean

Time point:

other: 24 hours

Score:

1

Max. score:

1

Reversibility:

fully reversible within: 48 hours

Results 7

Irritation parameter:

chemosis score

Basis:

mean

Time point:

other: 48 & 72 hours

Score:

0

Max. score:

0

Reversibility:

fully reversible

Irritant / corrosive response data:

Individual eye irritation scorer are presented in Table 1.

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

	RabbitNo.: 13625 (Male)				Rabbit No.: 13626 (Male)				Rabbit No.: 13627 (Male)
	Hours				Hours				Hours
	1	24	48	72	1	24	48	72	1	24	48	72
I. Cornea
A. Opacity	0	0^4	0	0	0	0^4	0	0	0	0^4	0	0
B. Area	4	4	4	4	4	4	4	4	4	4	4	4
(AxB)x5	0	0	0	0	0	0	0	0	0	0	0	0
IL Iris
A. Values	0	0	0	0	0	0	0	0	0	0	0	0
Ax5	0	0	0	0	0	0	0	0	0	0	0	0
III. Conjunctivae
A. Redness	2	1	0	0	1	1	0	0	2	1	1	0
B. Chernosis	1	0	0	0	1	0	0	0	1	0	0	0
C. Discharge	2	1	0	0	2	1	0	0	1	1	0	0
(A+B+C)x2	10	4	0	0	8	4	0	0	8	4	2	0
Total	10	4	0	0	8	4	0	0	8	4	2	0

⁴ 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, M-TMP caused conjunctival irritation, which cleared by 72 hours.

Executive summary:

A primary eye irritation test was conducted with rabbits to determine the potential for M-TMP to produce irritation from a single instillation via the ocular route. Under the conditions of this study, the test substance caused conjunctival irritation which cleared by 72 hours.

One-tenth of a milliliter 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. (see Table 2).

No corneal opacity or iritis was noted for any treated eye during the study. One hour after test substance instillation, all three treated eyes exhibited conjunctivitis. The overall incidence and severity of irritation decreased thereafter. All animals were free of ocular irritation within 72 hours.