Registration Dossier

Administrative data

Endpoint:
eye irritation: in vivo
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2004
Report Date:
2004

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 405 (Acute Eye Irritation / Corrosion)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method B.5 (Acute Toxicity: Eye Irritation / Corrosion)
Deviations:
no
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): DIBENZYL TRITHIOCARBONATE
- Physical state: yellow orange-colored solid
- Analytical purity: 96.2
- Purity test date: 2003-10-27
- Lot/batch No.: 1 UG 114
- Expiration date of the lot/batch: November 2004
- Storage condition of test material: at room temperature and protected from light

Test animals / tissue source

Species:
rabbit
Strain:
New Zealand White
Details on test animals or tissues and environmental conditions:
TEST ANIMALS
- Age at study initiation: 2 to 4 months old
- Weight at study initiation: 3.0 ± 0.1 kg.
- Housing: individually in polystyrene cages
- Diet : 110 pelleted diet (UAR, Villemoisson, Epinay-sur-Orge, France). Ad libitum
- Water : tap water filtered by a 0.22 micron membrane. Ad libitum
- Acclimation period: at least 5 days.
- Sex : male

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18 +/- 3°C
- Humidity (%): 30 to 70
- Air changes (per hr): 12 cycles/hour of filtered, non-recycled air.
- Photoperiod (hrs dark / hrs light): 12/12

Test system

Vehicle:
unchanged (no vehicle)
Controls:
not required
Amount / concentration applied:
A single dose of 100 mg of the test item in its original form was introduced into the conjunctival sac of the left eye after gently pulling the lower lid away from the eyeball
Duration of treatment / exposure:
The eyes were not rinsed after administration of the test item
Observation period (in vivo):
The eyes were examined approximately 1 hour, 24, 48 and 72 hours after administration of the test item. Since there were persistent ocular reactions at 72 hours, the observation period was extended up to their complete reversibility (day 15)
Number of animals or in vitro replicates:
3
Details on study design:
As possible irritant effects were anticipated, the test item was first administered to a single animal. Since the test item was not severely irritant on this first animal, it was then evaluated on two other animals.

REMOVAL OF TEST SUBSTANCE
- Washing: no

TOOL USED TO ASSESS SCORE: UV lamp after instillation of one or two drops of 0.5% sodium fluorescein solution

SCORING SYSTEM:
Ocular reactions were scored according to the following numerical scale:

Conjunctival lesions and discharge Chemosis (lids and/or nictitating membranes) .
no swelling ...........................................................................................................................0
any swelling above normal (includes nictitating membranes) .....................................1
obvious swelling with partial eversion of lids..................................................................2
swelling with lids about half-closed..................................................................................3
swelling with lids more than half-closed .........................................................................4

Redness (refers to palpebral and bulbar conjunctivae, cornea and iris) .
blood vessels normal ...........................................................................................................0
a number of blood vessels definitely hyperemic (injected)............................................1
diffuse, crimson colour, individual vessels not easily discernible ...............................2
diffuse, beefy red...................................................................................................................3

Discharge .
absence of discharge ..............................................................................................................0
slight discharge (does not include small amounts normally found in inner canthus)..1
discharge with moistening of lids and hairs adjacent to lids............................................ 2
discharge with moistening of lids and hairs on wide area around the eye......................3

Iris lesions .
normal ........................................................................................................................................0
markedly deepened rugae, congestion, swelling, moderate circum-corneal hyperemia, or injection, any of these or combination of any thereof, iris still reacting to light (sluggish reaction is positive) ...........................................................1
no reaction to light, haemorrhage, gross destruction (any or all of these) ...................2

Corneal lesions
Degree of opacity (area most dense taken for reading) .
no ulceration or opacity................................................................................................................................................................0
scattered or diffuse areas of opacity (other than slight dulling or normal lustre), details of iris clearly visible ...........1
easily discernible translucent area, details of iris slightly obscured ....................................................................................2
nacreous areas, no details of iris visible, size of pupil barely discernible ...........................................................................3
opaque cornea, iris not discernible through the opacity........................................................................................................4

Area of opacity .
one quarter (or less) but not zero................................................................................................1
greater than one quarter but less than a half.............................................................................2
greater than one half but less than three quarters....................................................................3
greater than three quarters up to whole area. ...........................................................................4

Any other lesions observed were noted.

Results and discussion

In vivo

Resultsopen allclose all
Irritation parameter:
conjunctivae score
Remarks:
(redness)
Basis:
animal #1
Time point:
other: overall at 24, 48 and 72 h
Score:
1.7
Max. score:
3
Reversibility:
fully reversible within: 6 days
Irritation parameter:
conjunctivae score
Remarks:
(redness)
Basis:
animal #2
Time point:
other: overall at 24, 48 and 72 h
Score:
1.3
Max. score:
3
Reversibility:
fully reversible within: 6 days
Irritation parameter:
conjunctivae score
Remarks:
(redness)
Basis:
animal #3
Time point:
other: overall at 24, 48 and 72 h
Score:
1.3
Max. score:
3
Reversibility:
fully reversible within: 6 days
Irritation parameter:
chemosis score
Basis:
animal #1
Time point:
other: overall at 24, 48 and 72 h
Score:
2.3
Max. score:
4
Reversibility:
fully reversible within: 15 days
Irritation parameter:
chemosis score
Basis:
animal #2
Time point:
other: overall at 24, 48 and 72 h
Score:
1
Max. score:
4
Reversibility:
fully reversible within: 6 days
Irritation parameter:
chemosis score
Basis:
animal #3
Time point:
other: overall at 24, 48 and 72 h
Score:
1
Reversibility:
fully reversible within: 6 days
Irritation parameter:
cornea opacity score
Basis:
animal: 1, 2 and 3
Time point:
other: overall at 24, 48 and 72 h
Score:
0
Max. score:
4
Irritation parameter:
iris score
Basis:
animal: 1, 2 and 3
Time point:
other: overall at 24, 48 and 72 h
Score:
0
Max. score:
2
Irritant / corrosive response data:
Very slight to moderate conjunctival reactions, including a very slight to moderate chemosis (grades 1 to 3), a very slight to moderate redness of the conjunctiva (grades 1 to 3) and a clear to whitish purulent discharge, were observed in all animals from day 1; some of these reactions persisted up to day 5 (2/3 animals) or 14 (1/3 animals).
No iritis and no corneal opacity were recorded.

Applicant's summary and conclusion

Interpretation of results:
other: not classified
Remarks:
Criteria used for interpretation of results: other: REGULATION (EC) No 1272/2008 OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL of 16 December 2008
Conclusions:
DIBENZYL TRITHIOCARBONATE is slightly irritant when applied topically to rabbits.
Executive summary:

The potential of DIBENZYL TRITHIOCARBONATE to induce ocular irritation was evaluated in rabbits according to OECD (No. 405, 24th April 2002) and EC (2004/73/EC, B.5, 29th April 2004) guidelines.

The test item was first administered to a single male New Zealand White rabbit. Since the test item was not severely irritant on this first animal, it was then evaluated simultaneously in two other animals.

A single dose of 0.1mL of the undiluted test item was instilled into the left conjunctival sac. The right eye was not treated and served as control. The eyes were not rinsed after administration of the test item.

Ocular reactions were observed approximately 1 hour, 24, 48 and 72 hours after the administration and then daily until reversibility of the ocular reactions. The mean values of the scores for chemosis, redness of the conjunctiva, iris lesions and corneal opacity were calculated for each animal.

Mean scores calculated for each animal over 24, 48 and 72 hours were 2.3, 1.0 and 1.0 for chemosis, 1.7, 1.3 and 1.3 for redness of the conjunctiva, 0.0, 0.0 and 0.0 for iris lesions and 0.0, 0.0 and 0.0 for corneal opacity.

Under these experimental conditions, DIBENZYL TRITHIOCARBONATE was slightly irritant when administered by ocular route to rabbits.