Bismuth tris(2-ethylhexanoate)

Eye irritation

Administrative data

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2018-09-24 to 2018-10-16

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Report date:

2019

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Version / remarks:

2017-10-09

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

signed on 2018-04-26

Test material

Test material information

Constituent 1

Reference substance name:

Bismuth tris(2-ethylhexanoate)

EC Number:

267-499-7

EC Name:

Bismuth tris(2-ethylhexanoate)

Cas Number:

67874-71-9

Molecular formula:

C24H45O6Bi

IUPAC Name:

bismuth(3+) tris(2-ethylhexanoate)

Test material form:

liquid: viscous

Details on test material:

Appearance: brown viscous liquid

Test animals / tissue source

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Source: Charles River Deutschland, 97633 Sulzfeld, Germany
- Age at study initiation: approximately 12 – 13 weeks old
- Weight at study initiation: 2.3 kg
- Housing: individually housed in ABS-plastic or Noryl rabbit cages, floor 4200 cm²
- Diet (ad libitum): autoclaved hay and to Altromin 2123 maintenance diet for rabbits, rich in crude fibre
- Water (ad libitum): tap water
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature: 18 ± 3 °C
- Relative humidity: 55 ± 10%
- Air changes: at least 10 x / hour
- Photoperiod (hrs dark / hrs light): 12/12

Test system

Vehicle:

unchanged (no vehicle)

Controls:

no

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.1 ml of the test item applied in the conjunctival sac of one eye. Untreated eye served as control.

Duration of treatment / exposure:

not applicable

Observation period (in vivo):

1, 24, 48 and 72 hours as well as 4 to 21 days after test item application

Duration of post- treatment incubation (in vitro):

not applicable

Number of animals or in vitro replicates:

1 male rabbit

Details on study design:

PREPARATION OF THE ANIMALS
Within 24 hours before the test and immediately prior to the application both eyes of the animal were examined.
Approx. 15 hours before the application the eyes were examined with the aid of a fluorescein solution (Fluoreszein SE Thilo®). The eyes were rinsed with physiological saline 0.9 % NaCl after the examination. The animal did not show eye irritation, ocular defects, or pre-existing corneal injury.

INITIAL AND CONFIRMATORY TEST
The in vivo test was performed initially using one animal. The results of the initial test indicated that the test item is corrosive or severe irritant to the eye using the procedure described. Therefore, no additional animals were treated due to animal welfare reasons.

USE OF TOPICAL ANESTHETICS AND SYSTEMIC ANALGESICS
One hour before the application of the test item, 0.01 mg/kg of buprenorphine (Temgesic®) was administered subcutaneously in order to achieve a therapeutic level of systemic analgesia.
Approx. 5 minutes prior to the application of the test item, 1-2 drops of an ocular anaesthetic (Proparakaine-POS® hydrochloride ophthalmic 0.5% solution) were administered in both the treated and the control eye of the animal.
To prevent pain and distress after the application of the test item the animal was treated with doses of buprenorphine and meloxicam to provide a continued therapeutic level of systemic analgesia:
- After test substance application the test animal was dosed with 0.03 mg/kg bw of buprenorphine at the discretion of the veterinarian: 11 hours (day 0) post-application once; day 1 and day 2 twice; day 3 once.
- After test substance application the test animal was dosed with 0.5 mg/kg bw of meloxicam: 8 hours (day 0) up to day 5 and from day 7 up to day 21.
- Day 6, 20 and 21 no analgesic medication.

REMOVAL OF TEST SUBSTANCE
- Washing: treated eye was rinsed with physiological saline 0.9 % NaCl after examination with fluorescein solution
- Time after start of exposure: 1 hour after the application
The eyes were not rinsed to remove residues of the test item, foreign bodies or incrustation 24 hours after application.

SCORING SYSTEM
according to Draize scale

TOOL USED TO ASSESS SCORE: slit lamp biomicroscope / fluorescein
Approximately 15 hours before the application the eyes were examined with the aid of a fluorescein solution.
24 hours post-application and from then on daily until end of the observation period, the treated eye was examined with the aid of a fluorescein solution and a slit lamp biomicroscope. After the examination the eye was rinsed with physiological saline 0.9% NaCl.

OBSERVATIONS
- body weight: prior to the administration, 72 hours after administration and at the end of the observation period
- clinical observations: The eyes were comprehensively evaluated for the presence or absence of ocular lesions one hour and then 24, 48 and 72 hours after application. The eyes were further examined for signs of irritation throughout the observation period.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

cornea opacity score

Basis:

mean

Remarks:

animal #1

Time point:

24/48/72 h

Score:

1

Max. score:

4

Reversibility:

not reversible

Results 2

Irritation parameter:

iris score

Basis:

mean

Remarks:

animal #1

Time point:

24/48/72 h

Score:

1.33

Max. score:

2

Reversibility:

not reversible

Results 3

Irritation parameter:

chemosis score

Basis:

mean

Remarks:

animal #1

Time point:

24/48/72 h

Score:

1.33

Max. score:

4

Reversibility:

not reversible

Results 4

Irritation parameter:

conjunctivae score

Basis:

mean

Remarks:

animal #1

Time point:

24/48/72 h

Score:

1.67

Max. score:

3

Reversibility:

not reversible

Irritant / corrosive response data:

Animal # 1:
- conjunctival redness score 1 one hour post-application. 24 hours post-application a conjunctival redness score 2 was observed before the score decreased to 1 from 72 hours until 12 days post-application. No conjunctival redness was detected 13 days after installation of the test item. 14 to 21 days after dosing the animal showed conjunctival redness score 1. The effect was not fully reversible within the observation period of 21 days after application of the test material. The mean score of animal no. 1, following grading at 24, 48 and 72 h after installation of Bismuth tris (2-ethylhexanoate), was calculated to be 1.66.
- conjunctival chemosis score 3 one hour and score 2 24 hours post-application. From 72 hours to 11 days post-administration of the test material conjunctival chemosis was assessed with score 1. 12 days after test item installation score 2 was observed, before the score decreased again to 1 from 13 days post-application until end of the observation period. The effect was not fully reversible within the 21 days-observation period. The mean score of animal no. 1, following grading at 24, 48 and 72 h after installation of Bismuth tris (2-ethylhexanoate), was calculated to be 1.33.
- Iris lesion score 1 one hour post-application and score 2 24 hours post-application. From 72 hours until end of the observation period iris lesion score 1 was observed in the tested animal. The effect was not fully reversible within the observation period of 21 days after dosing. The mean score of animal no. 1, following grading at 24, 48 and 72 h after installation of Bismuth tris (2-ethylhexanoate), was calculated to be 1.33.
- Cornea opacity score 1 throughout the 21 days-observation period. The effect was not fully reversible within the test period. The mean score of animal no.1, following grading at 24, 48 and 72 h after installation of the test material, was calculated to be 1.00.

Local effects were observed in animal #1:
The observed local effects comprised slight to moderate hypersecretion, half eyelid closure and incline of the head.

Upon fluorescein examinations starting 24 hours post-application, the treated eyes of animal no. 1 showed corneal daily lesions (starting with approx. 100% of the area) until 12 days post-application. From 13 days to 19 days after administration of the test item no stainable lesions were recorded in the test animal, while from 20 days to 21 days post-application slightly visible changes in the cornea were apparent (approx. 10% of the area).

Other effects:

- clinical observations: neither mortality nor significant clinical signs of toxicity were observed.
- body weight: the body weight development was within the expected range.

Applicant's summary and conclusion

Interpretation of results:

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

Conclusions:

The substance is serious eye damaging.
According to Annex I of Regulation (EC) 1272/2008 and subsequent adaptations, the test item Bismuth tris (2-ethylhexanoate) has to be classified as serious eye damaging (Category 1).