Trilithium orthophosphate

Eye irritation

Administrative data

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2015-07-28

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2015

Report date:

2015

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 438 (Isolated Chicken Eye Test Method for Identifying Ocular Corrosives and Severe Irritants)

Version / remarks:

(2013)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Trilithium orthophosphate

EC Number:

233-823-0

EC Name:

Trilithium orthophosphate

Cas Number:

10377-52-3

Molecular formula:

Li3O4P

IUPAC Name:

trilithium orthophosphate

Test material form:

solid

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- lot/batch No.of test material: 1153
- Expiration date of the lot/batch: May 2020

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Store at room temperature (15-30 °C). Keep container tightly closed.

Test animals / tissue source

Species:

other: Isolated Chicken Eyes

Details on test animals or tissues and environmental conditions:

TEST SYSTEM
- Source: TARAVIS KFT. 9600 Sárvár, Rábasömjéni út 129., Hungary

Test system

Vehicle:

unchanged (no vehicle)

Controls:

yes

Amount / concentration applied:

TEST MATERIAL
- Amount applied: 0.03 g

Duration of treatment / exposure:

The gentle rinsing with 20 mL saline was performed in all test item treated eyes after the 30, 75 and 120 minutes of observation. At 180 minutes of observation one of the three eyes was totally clear, with the two other eyes gentle rising was performed again, but they were not totally cleared at 240 minutes after the post-treatment rinse.

Observation period (in vivo):

Please refer to duration of treatment.

Number of animals or in vitro replicates:

3 eyes per treatment group were used.

Details on study design:

EXPERIMENTAL PROCEDURE
Base line assessments:
At the end of the acclimatization period, a zero reference measurement was recorded for cornea thickness and opacity to serve as a baseline (t=0) for each individual eye. The cornea thickness of the eyes should not change by more than ± 5-7 % within approximately 45 to 60 minutes before the start of application. Changes in thickness were not observed in the eyes. Following the equilibration period, the fluorescein retention was measured. Baseline values were required to evaluate any potential test item related effects after treatment. The location of any minor findings was marked on the record sheet as a drawing, if applicable. If any eye was considered to be unsuitable following baseline assessment, it was discarded.

Test item treatment:
After the zero reference measurements, one out of three eyes in the treatment group was held in a horizontal position and lithium phosphate was applied in an amount of 0.03 g by attempting to cover the cornea surface uniformly with the test substance, while taking care not to damage or touch the cornea with the application equipment. This procedure was repeated with the remaining two eyes in the treatment group. The three positive control eyes were treated in a similar way with 0.03 g Imidazole. One negative control eye was treated with saline solution. The saline solution was applied in a volume of 30 μL from micropipette, in such a way that the entire surface of the cornea was covered with negative control, taking care not to damage or touch the cornea with the application equipment.

Test item removal:
The Imidazole and test item were stuck on the corneas surface in all eyes at 30, 75, 120, 180, and 240 minutes after the post-treatment rinse.
The gentle rinsing with 20 mL saline was performed in all Imidazole treated eyes after the 30, 75, 120 and 180 minutes of observation, but cornea surfaces were not totally cleared at 240 minutes after the post-treatment rinse.
The gentle rinsing with 20 mL saline was performed in all test item treated eyes after the 30, 75 and 120 minutes of observation. At 180 minutes of observation one of the three eyes was totally clear, with the two other eyes gentle rising was performed again, but they were not totally cleared at 240 minutes after the post-treatment rinse.

Measurements:
The control and test item treated eyes were evaluated pre-treatment and at approximately 30, 75, 120, 180 and 240 minutes after the post-treatment rinse. Minor variations within ± 5 minutes were considered acceptable.
The cornea thickness and cornea opacity were measured at all time points. Fluorescein retention was measured on two occasions, at base line (t=0) and 30 minutes after the post-treatment rinse.

Evaluation:
The endpoints evaluated were corneal opacity, swelling, fluorescein retention, and morphological effects (e.g., pitting or loosening of the epithelium).
Results from corneal opacity, swelling, and fluorescein retention were evaluated separately to generate an Isolated Chicken Eye (ICE) class for each endpoint. The ICE classes for each endpoint were then combined to generate an Irritancy Classification for each test substance.

Results and discussion

In vitro

Results

Results 1

Irritation parameter:

percent corneal swelling

Remarks:

mean

Run / experiment:

swelling up to 75 min

Value:

1

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: ICE class I

Results 2

Irritation parameter:

percent corneal swelling

Remarks:

mean

Run / experiment:

swelling at up to 240 min

Value:

3

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: ICE class I

Results 3

Irritation parameter:

cornea opacity score

Remarks:

mean

Value:

1

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: ICE class II

Results 4

Irritation parameter:

fluorescein retention score

Remarks:

mean

Value:

3

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: ICE class IV

In vivo

Irritant / corrosive response data:

Ocular corrosion and severe irritation potential was not observed for the test substance. Based on the overall ICE Class the positive control Imidazole was classified as corrosive/severely irritating, UN GHS Classification: Category 1. Based on the overall ICE Class the negative control NaCl (9 g/L saline) had no significant effects on the chicken eye in this study.

Applicant's summary and conclusion

Interpretation of results:

study cannot be used for classification

Conclusions:

Based on the results of the in vitro test for eye corrosives and severe irritants in isolated chicken eyes, ocular corrosion and severe irritation potential was not observed for the test substance. On the other hand, the results were not conclusive regarding differentiation between irritation or non irritation potential.

Executive summary:

In order to evaluate the potential ocular corrosivity and irritancy of the test item lithium phosphate an isolated chicken eye test was performed according to OECD Guideline 438 and EU method B.48. The test item lithium phosphate and positive control (Imidazole) were ground before use in the study. They were applied in an amount of 0.03 g/eye by powdering the entire surface of the cornea attempting to cover the cornea surface uniformly with the test substance or positive control. Three test item treated eyes and three positive control eyes were used in this study. One negative control eye was treated with 30 μL saline solution. After an exposure period of 10 seconds from the end of the application the cornea surface was rinsed thoroughly with ~20 mL saline solution at ambient temperature and this procedure was repeated for each eye. In this ICET, lithium phosphate did not cause ocular corrosion or severe irritation in the enucleated chicken eyes. Positive and negative controls showed the expected results. The experiments were considered to be valid.

In this in vitro eye corrosives and severe irritants study, using the Isolated Chicken Eye model with lithium phosphate, no ocular corrosion or severe irritation potential was observed. According to guideline OECD 438, lithium phosphate overall in vitro classification is neither UN GHS Classification Category I (an ocular corrosive or severe eye irritant) nor No Category. Thus, test item has been categorized as “No prediction can be made”.