Benzyl 4-[(1-butyl-5-cyano-1,6-dihydro-2-hydroxy-4-methyl-6-oxopyridin-3-yl)azo]benzoate

Eye irritation

Administrative data

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

17 August to 21 August, 1987

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1987

Report date:

1987

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Version / remarks:

1981

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Disperse Yellow 231

IUPAC Name:

Disperse Yellow 231

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
- Source: David Percival Limited, Moston, Sandbach, Cheshire, UK and Nottingham University, School of Agriculture, Sutton Bonington, Leicestershire, UK
- Age at study initiation: 12 to 16 weeks old
- Weight at study initiation: 2.72 to 3.08 kg
- Housing: individually in suspended metal cages
- Diet: ad libitum; Rabbit Diet, Preston Farmers Limited, New Leake, Boston, Lincolnshire, UK
- Water: ad libitum
- Acclimation period: minimum 5 days

ENVIRONMENTAL CONDITIONS
- Temperature: 18-21 °C
- Humidity: 65-68 %
- Air changes: ca. 15 per hr
- Photoperiod (hrs dark / hrs light): 12/12 controlled by a time switch

Test system

Vehicle:

unchanged (no vehicle)

Controls:

yes, concurrent no treatment

Amount / concentration applied:

TEST MATERIAL
- Amount applied: 0.1 ml finely ground test item

Duration of treatment / exposure:

ongoing (not removed after application)

Observation period (in vivo):

As no ocular irritation was observed at the 72 h reading, the study was terminated at 72 hours

Number of animals or in vitro replicates:

3

Details on study design:

APPLICATION
- Preparation: a volume of 0.1 ml of unchanged test material (found to weigh ca. 42 mg) was ground into a fine powder using a mortar and pestle, and measured by gently compacting the required volume into an adapted syringe
- Application: placed into the right eye of each rabbit by gently pulling the lower lid away from the eyeball to form a cup into which the test item was dropped; the upper and lower lids were then held together for ca. 1 second to prevent loss of test item
- Observations: 1, 24, 48 and 72 hours after application

REMOVAL OF TEST SUBSTANCE
- Removal: no removal or washing was performed

TOOL USED TO ASSESS SCORE: light source of a standard ophthalmoscope (Keeler)

SCORING SYSTEM:
- Method of calculation: Draize, J. H. (1959) "The Appraisal of the Safety of Chemicals in Foods, Drugs and Cosmetics", as follows:

Corneal opacity: degree of intensity (area most dense taken for reading)
0 – No ulceration opacity
1 – Scattered or diffuse areas of opacity (other than slight dulling of normal lustre), details of iris clearly visible
2 – Easily discernible translucent area, details of iris slightly obscured
3 – Opalescent area, no details of iris visible, size of pupil barely discernible
4 – Opaque cornea, iris not discernible through the opacity

Iris
0 – Normal
1 – Markedly deepened rugae, congestion, swelling, moderate circumcorneal hyperaemia, or injection, any of these or a combination of any thereof, iris still reacting to light (sluggish reaction is positive)
2 – No reaction to light, haemorrhage, gross destruction (any or all of these)

Conjunctival redness: refers to palpebral and bulbar conjunctiva excluding cornea and iris
0 - Blood vessels normal
1 - Some blood vessels definitely hyperaemic (injected) above normal
2 – Diffuse, crimson colour, individual vessels not easily discernible
3 – Diffuse beefy red*

Chemosis: lids and/or nictitating membranes
0 – No swelling
1 – Any swelling above normal (includes nictitating membrane)
2 – Obvious swelling with partial eversion of lids
3 – Swelling with lids about half closed
4 – Swelling with lids about half closed to completely closed

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

cornea opacity score

Basis:

animal: #1, #2, #3

Time point:

24/48/72 h

Score:

0

Max. score:

0

Results 2

Irritation parameter:

iris score

Basis:

animal: #1, #2, #3

Time point:

24/48/72 h

Score:

0

Max. score:

0

Results 3

Irritation parameter:

conjunctivae score

Basis:

animal: #1, #2, #3

Time point:

24/48/72 h

Score:

0.33

Max. score:

1

Reversibility:

fully reversible within: 48 h

Results 4

Irritation parameter:

chemosis score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0.33

Max. score:

1

Reversibility:

fully reversible within: 48 h

Results 5

Irritation parameter:

chemosis score

Basis:

animal: #2, #3

Time point:

24/48/72 h

Score:

0

Max. score:

0

Irritant / corrosive response data:

- No corneal opacity was noted in the study period.
- Iridial inflammation was observed only in one animal and only at 1 hour after application.
- Grade 2 conjunctival redness was observed in all three animals at one hour after application, which persisted at 24 h (grade 1) and was reversible within 48 hours after application.
- Grade 1-2 chemosis was observed in all three animals at one hour after application, which persisted at 24 h in just one animal (grade 1), and was reversible within 48 hours after application.

Any other information on results incl. tables

Individual and mean scores for cornea, iris & conjunctivae.

Rabbit no.	Time after treatment (h)	Corneal opacity	Iritial inflammation	Conjunctival redness	Conjunctival chemosis
#1	1	0	0	2	2
	24	0	0	1	1
	48	0	0	0	0
	72	0	0	0	0
	total (24, 48, 72 h)	0	0	1	1
	mean (24, 48, 72 h)	0	0	0.333333	0.333333
#2	1	0	0	2	1
	24	0	0	1	0
	48	0	0	0	0
	72	0	0	0	0
	total (24, 48, 72 h)	0	0	1	0
	mean (24, 48, 72 h)	0	0	0.333333	0
#3	1	0	1	2	2
	24	0	0	1	0
	48	0	0	0	0
	72	0	0	0	0
	total (24, 48, 72 h)	0	0	1	0
	mean (24, 48, 72 h)	0	0	0.333333	0

Applicant's summary and conclusion

Interpretation of results:

other: not classified according to the CLP Regulation (EC 1272/2008)

Conclusions:

The test item induced slight conjunctival redness and chemosis until 24 hours after application.

Executive summary:

The eye irritation/eye damage potential of the test item was evaluated in an experimental study according to a method based on the OECD guideline 405 (1981). 0.1 ml of finely ground test item (weighing ca. 42 mg) was placed into the right conjunctival sac of three New Zealand White rabbits using an adapted syringe (no rinsing/removal performed). The eye was then monitored for corneal opacity, iridic inflammation, conjunctival redness and chemosis (using the Draize irritation scale) at 1, 24, 48 and 72 hours after application using a standard ophthalmoscope. The left eye may be considered an untreated control.

As no signs of irritation or damage were evident at 72 hours after application, the study was terminated. No corneal opacity was noted in the study period, and iridial inflammation was observed only in one animal and only at 1 hour after application. Grade 2 conjunctival redness was observed in all three animals at one hour after application, which persisted at 24 h (grade 1) and was reversible within 48 hours after application. Grade 1 -2 chemosis was observed in all three animals at one hour after application, which persisted at 24 h in just one animal (grade 1), and was reversible within 48 hours after application. The mean (24, 48 and 72 h) irritation scores for (i) corneal opacity, (ii) iridial inflammation, (iii) conjunctival redness and (iv) chemosis were subsequently calculated to be (i) 0 in all animals, (ii) 0 in all animals, (iii) 0.33 in all animals, and (iv) 0.33 in one animal and 0 in two animals.