Reaction mass of barium chromate, copper dichromium tetraoxide and copper oxide

Eye irritation

Administrative data

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 23 February 2010 to 01 June 2010

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: No guideline was followed, but study was compliant to GLP; and there was adequate coherence between data, comments and conclusions.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

The principle of this evaluation is based on the measurement of two factors: the opacity and the permeability of the treated corneas. The changes in these parameters correspond to the damages induced to the tissues.
The method used is adapted from that described by Gautheron P. & al. (1992) Fundam. Appl. Toxicol. 18 442-449.

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

dioxo-1,3-dioxa-2-chroma-4-baracyclobutane; dioxo-2,4-dioxa-3-cupra-1,5-dichromapentane; oxocopper

EC Number:

701-287-1

Molecular formula:

CuO, CuCr2O4, BaCrO4

IUPAC Name:

dioxo-1,3-dioxa-2-chroma-4-baracyclobutane; dioxo-2,4-dioxa-3-cupra-1,5-dichromapentane; oxocopper

Details on test material:

- Name of test material (as cited in study report): Chromite de cuivre
- Substance type: multiconstituents
- Physical state: black powder
- Composition of test material, percentage of components: 34% of copper, 8.5% of baryum, 31% of chrome
- Purity test date: 11 January 2010
- Lot/batch No.: 09/0177
- Expiration date of the lot/batch: 17 August 2014
- Storage condition of test material: in darkness at room temperature

Test system

Vehicle:

unchanged (no vehicle)

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 750 mg ± 75 mg of the test item was gently applied to the cornea, as uniformly as possible

Duration of treatment / exposure:

30 minutes (first experiment) and 10 minutes (second experiment)

Observation period (in vivo):

Not applicable

Number of animals or in vitro replicates:

Not applicable

Details on study design:

REMOVAL OF TEST SUBSTANCE
- Washing (if done): at the end of each treatment period, the dosage form having adhered to the walls of the compartment was eliminated using a cotton bud (10-minute treatment) and/or a pipette of heated cMEM (32°C) (both 30- and 10-minute treatments).

Results and discussion

In vitro

Results

Results 1

Irritation parameter:

other: Mean in vitro score = Corrected opacity + (15 x Corrected OD490nm)

Run / experiment:

Mean

Value:

51.6

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

not applicable

Results 2

Irritation parameter:

other: Mean in vitro score = Corrected opacity + (15 x Corrected OD490nm)

Run / experiment:

Mean

Value:

42.8

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Any other information on results incl. tables

For each experiment, the acceptance criteria were fulfilled:

- the individual corneal opacity values of negative controls were < 10 in both experiments,

- the individual OD_490nm values of negative control corneas were < 0.100 in both experiments,

- the solution of fluoresceine (at 5 mg/mL in DPBS) diluted 1:1000 in cMEM had OD_490nm values between 0.850 and 0.940 in both experiments,

- following the 30-minute treatment, the positive control mean in vitro scores was 124.1, thus demonstrating the sensitivity of the test system under the experimental conditions of this study.

No notable opaque spots or irregularities were observed on negative control corneas, either following the 30-minute treatment or following the 10-minute treatment.

Residual test item was observed on test item-treated corneas, following both the 30- and 10-minute treatments.

Following the 30-minute treatment, the mean in vitro score was 51.6. Then following the 10- minute treatment, the mean in vitro score was 42.8.

The test item is classified according the following table:

Mean in vitro score at the 30-minute treatment (X)		Mean in vitro score at the 4-hour treatment (Z) or 10-minute treatment(Y)	Class
X ≤ 10	and	Z ≤ 40	1	Slightly irritant
		40 < Z ≤ 100	2	Moderately irritant
		Z > 100	3	Irritant to severely irritant
10 < X ≤ 25	and	Y ≤ 10	2	Moderately irritant
		10 < Y ≤ 25	2 - 3	Moderately irritant to irritant
		Y > 25	3	Irritant to severely irritant
25 < X ≤ 55	and	Y ≤ 10	2 - 3	Moderately irritant to irritant
		Y > 10	3	Irritant to severely irritant

Applicant's summary and conclusion

Interpretation of results:

other: irritant to severely irritant

Remarks:

Criteria used for interpretation of results: other: see table on page 15 of the report

Conclusions:

Under the experimental conditions of this study, according to both mean in vitro scores of the 30-minute and 10-minute treatments, the test item Chromite de cuivre tested in its original form is classified as irritant to severely irritant for the isolated calf cornea.

Executive summary:

Method:

The corneas were obtained from the eyes of freshly slaughtered calves at the abattoir. They were mounted in the corneal holders with the endothelial side against the O-ring of the posterior half of the holder. Both compartments of the corneal holder were filled in excess with Minimal Essential Medium Eagle completed with 1% fetal calf serum plus penicillin/streptomycin (cMEM), then the

holders were preincubated for 1 hour at 32°C.

Three corneas were used for each treated series (test item, positive control and negative control).

Before the treatment, a first opacity measurement was performed using an opacitometer (determining the light transmission through the center of each mounted cornea).

For the treatment, the test item was used in its original form.

The test item was tested sequentially in two consecutive experiments.

As the mean in vitro score at the 30-minute treatment was > 10 but ≤ 55, the second experiment was undertaken using a 10-minute treatment.

At the completion of the treatment period, the test item was removed from the front opening of the anterior part of the holder and the epithelium was washed.

Following the 10- and 30-minute treatments, the corneas were incubated for 2 hours at 32°C. At the completion of the 2-hour incubation period, the second opacity measurement was performed.

After the second opacity measurement, the medium was removed from both compartments of each holder. The posterior compartment was refilled with cMEM at 32°C, while the anterior compartment received 1 mL of a 5 mg/mL fluoresceine solution in Dulbecco's Phosphate-Buffered Saline (DPBS). Then, the holders were incubated vertically for 90 minutes at 32°C.

At the end of the 90-minute incubation, the optical density of the solution from the posterior compartment of the holder was measured at 490 nm in order to determine the permeability of the cornea. Then the cornea was removed from the holder and observed for opaque spots and other irregularities.

Results:

For each experiment, the acceptance criteria were fulfilled and the study was therefore considered to be valid.

No notable opaque spots or irregularities were observed on negative control corneas, either following the 30-minute treatment or following the 10-minute treatment.

Residual test item was observed on test item-treated corneas, following both the 30- and 10-minute treatments.

Following the 30-minute treatment, the mean in vitro score was 51.6. Then following the 10- minute treatment, the mean in vitro score was 42.8.

Conclusion:

Under the experimental conditions of this study, according to both mean in vitro scores of the 30-minute and 10-minute treatments, the test item Chromite de cuivre tested in its original form is classified as irritant to severely irritant for the isolated calf cornea.