4H-Pyrido[1,2-a]pyrimidin-4-one, 3-(2-chloroethyl)-9-hydroxy-2-methyl-, hydrochloride (1:1)

Eye irritation

Administrative data

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

2003-05-14 to 2004-09-22

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Remarks:

Non GLP study with limited details on the test substance and methodology; however, sufficient information was provided to deem the study reliable with restrictions.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2004

Report date:

2004

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

The ocular irritancy potential of the test material was assessed using the rabbit enucleated eye test (REET). This method involved the application of the test material onto the cornea of the enucleated eye.

GLP compliance:

no

Remarks:

The study was conducted in a facility operating to Good Laboratory Practice within the UK national GLP monitoring programme, but the study report has not been audited by the QA Unit. No formal claim of GLP compliance was made for the study.

Test material

Test material information

Constituent 1

Reference substance name:

3-(2-CHLOROETHYL)-9-HYDROXY-2-METHYL-4H-PYRIDO[1,2-A]PYRIMIDIN-4-ONE HYDROCHLORIDE (1:1)

EC Number:

617-648-0

Cas Number:

849727-62-4

Molecular formula:

C11H11ClN2O2.HCl

IUPAC Name:

3-(2-CHLOROETHYL)-9-HYDROXY-2-METHYL-4H-PYRIDO[1,2-A]PYRIMIDIN-4-ONE HYDROCHLORIDE (1:1)

Test material form:

solid: particulate/powder

Test animals / tissue source

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

TEST ANIMALS: enucleated eye obtained from New Zealand White rabbits

ENVIRONMENTAL CONDITIONS
- Temperature (deg C): 32 °C +/- 1.5 °C.
- Humidity (%): no data
- Air changes (per hr): no data
- Photoperiod (hrs dark / hrs light): no data

Test system

Vehicle:

unchanged (no vehicle)

Controls:

yes, concurrent negative control

Amount / concentration applied:

TEST MATERIAL
- Amount applied: 0.1 mL
- Concentration: undiluted

NEGATIVE CONTROL
- amount applied: 0.1 mL
- Concentration (if solution): 0.9%

Duration of treatment / exposure:

single application

Observation period (in vivo):

- corneal opacity and corneal epithelium condition: 60, 120, 180 and 240 min
- fluorescein uptake: 240 min
- corneal swelling: 60, 120 and 240 min

Number of animals or in vitro replicates:

five enucleated eyes (3 for the test group, and 2 for the control group)

Details on study design:

REMOVAL OF TEST SUBSTANCE
- Washing (if done): no data
- Time after start of exposure: no data


SCORING SYSTEM:
McDonald-Shadduck Score System.
The scoring scheme measures the severity of corneal cloudiness and the area of the cornea involved.
Severity of corneal cloudiness is graded as follows:
0 = Normal cornea. Appears with the slit-lamp as having a bright grey line on the epithelial surface and a bright grey appearance of the stroma.
1 = Some loss of transparency. Only the anterior half of the stroma is involved as observed with an optical section of the slit-lamp. The underlying structures are clearly visible with diffuse illumination, although some cloudiness can be readily apparent with diffuse illumination.
2 = Moderate loss of transparency. In addition to involving the anterior stroma, the cloudiness extends all the way to the endothelium. The stroma has lost its marble-like appearance and is homogeneously white. With diffuse, illumination, underlying structures are clearly visible.
3 = Involvement of the entire thickness of the stroma. With optical section, the endothelial surface is still visible. However, with diffuse illumination the underlying structures are just visible.
4 = Involvement of the entire thickness of the stroma. With the optical section cannot clearly visualise the endothelium. With diffuse illumination, the underlying structures cannot be seen.

The surface of the cornea relative to the area of cloudiness is divided into five grades from 0 to 4:
0 = Normal cornea with no area of cloudiness
1 = 1 to 25% area of stromal cloudiness
2 = 26 to 50% area of stromal cloudiness
3 = 51 to 75% area of stromal cloudiness
4 = 76 to 100% area of stromal cloudiness

FLUORESCEIN
The use of fluorescein is a valuable aid in defining epithelial damage for fluorescein staining. The area can be judged as a 0 to 4 scale using the same terminology as for corneal cloudiness.The intensity of fluorescein staining can be divided into a 0 to 4 scale:
0 = Absence of fluorescein staining
1 = Slight fluorescein staining confined to a small focus. With diffuse illumination the underlying structures are clearly visible, although there is some loss of detail.
2 = Moderate fluorescein staining confined to a small focus. With diffuse illumination the underlying structures are clearly visible, although there is some loss of detail.
3 = Marked fluorescein staining. Staining may involve a larger portion of the cornea. With diffuse illumination underlying structures are barely visible but are not completely obliterated.
4 = Extreme fluorescein staining. With diffuse illumination the underlying structures cannot be seen.

REFERENCE: Hackett R B and McDonald T O, Eye Irritation. In: Advances in Modern Toxicology: Dermatoxicology. 4th ed. (F Marzulli and H Maibach, eds) Hemisphere Publishing Corporation, Washington DC, 1991, pp 749-815

TOOL USED TO ASSESS SCORE: Slit-Lamp, biomicroscope and fluorescein

Results and discussion

In vitro

Results

Results 1

Irritation parameter:

cornea opacity score

Run / experiment:

1

Value:

0

Negative controls validity:

valid

Remarks on result:

other: 0 = normal cornea. Some test substance has adhered across the cornea.

Results 2

Irritation parameter:

fluorescein retention score

Run / experiment:

1

Value:

1

Negative controls validity:

valid

Remarks on result:

other: 1 = Slight fluorescein staining confined to a small focus. Some residual test substance adhered to the cornea.

Remarks:

Both the fluorescein integration and area parameters were examined at this time point; the control values were all 0.0

Results 3

Irritation parameter:

percent corneal swelling

Run / experiment:

1

Value:

13.9

Negative controls validity:

valid

Remarks on result:

other: mean of three eyes after 60 min post dosing

Results 4

Irritation parameter:

percent corneal swelling

Run / experiment:

1

Value:

19.2

Negative controls validity:

valid

Remarks on result:

other: mean of three eyes 120 min post dosing

Results 5

Irritation parameter:

percent corneal swelling

Value:

26.5

Negative controls validity:

valid

Remarks on result:

other: mean of three eyes 240 min post dosing

Other effects / acceptance of results:

Corneal epithelium condition: test and control eyes were normal at all times.

Any other information on results incl. tables

Table 1. Results obtained for corneal opacity at 60, 120, 180, and 240 minutes post exposure.

	Corneal Opacity
	Observation Period (minutes post dosing)
	60		120		180		240
	Cldy	Area	Cldy	Area	Cldy	Area	Cldy	Area
Test Eyes	0	0*	0	0*	0	0*	0	0*
	0	0*	0	0*	0	0*	0	0*
	0	0*	0	0*	0	0*	0	0*
Control Eyes	0	0	0	0	0	0	0	0
	0	0	0	0	0	0	0	0

Cldy = Corneal opacity

* = Some test substance has adhered across the cornea

 

Table 2. Results obtained for corneal epithelium condition at 60, 120, 180, and 240 minutes post exposure.

	Corneal Epithelium Condition
	Observation Period (minutes post dosing)
	60	120	180	240
Test Eyes	Normal	Normal	Normal	Normal
	Normal	Normal	Normal	Normal
	Normal	Normal	Normal	Normal
Control Eyes	Normal	Normal	Normal	Normal
	Normal	Normal	Normal	Normal

 

 

Table 3. Results obtained for fluorescein uptake 240 minutes post exposure.

	Fluorescein Uptake (240 minutes)
	Test Eyes			Control Eyes
Int	0	0	0	0	0
Area	0*	0*	0*	0	0

Int = Intensity of fluorscein uptake

* = Some residual test substance adhered to the cornea.

 

Table 4. Results obtained for corneal swelling at 60, 120, and 240 minutes post exposure.

	Corneal Swelling (%)(minutes post dosing)
	60	120	240
Test Eyes	13.9	19.2	26.5
Control Eyes	0.0	0.0	0.8

Test eyes results are the mean of three eyes while control eyes are the mean of two eyes

Applicant's summary and conclusion

Interpretation of results:

Category 1 (irreversible effects on the eye) based on GHS criteria

Conclusions:

The test material is considered likely to have the potential to cause severe ocular irritancy in vivo.