Calcium titanium trioxide

Eye irritation

Administrative data

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

2018

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:

2018

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 437 (Bovine Corneal Opacity and Permeability Test Method for Identifying i) Chemicals Inducing Serious Eye Damage and ii) Chemicals Not Requiring Classification for Eye Irritation or Serious Eye Damage)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Calcium titanium trioxide

EC Number:

234-988-1

EC Name:

Calcium titanium trioxide

Cas Number:

12049-50-2

Molecular formula:

Ca.O3Ti

IUPAC Name:

Calcium titanium trioxide

impurity 1

Reference substance name:

Titanium dioxide

EC Number:

236-675-5

EC Name:

Titanium dioxide

Cas Number:

13463-67-7

Molecular formula:

O2Ti

IUPAC Name:

dioxotitanium

impurity 2

Reference substance name:

Silicon dioxide

EC Number:

231-545-4

EC Name:

Silicon dioxide

Cas Number:

7631-86-9

Molecular formula:

O2Si

IUPAC Name:

Silicon dioxide

impurity 3

Reference substance name:

Aluminium oxide

EC Number:

215-691-6

EC Name:

Aluminium oxide

Cas Number:

1344-28-1

Molecular formula:

Al2O3

IUPAC Name:

oxo(oxoalumanyloxy)alumane

impurity 4

Reference substance name:

Magnesium oxide

EC Number:

215-171-9

EC Name:

Magnesium oxide

Cas Number:

1309-48-4

Molecular formula:

MgO

IUPAC Name:

magnesium oxygen(-2) anion

impurity 5

Reference substance name:

Diniobium pentaoxide

EC Number:

215-213-6

EC Name:

Diniobium pentaoxide

Cas Number:

1313-96-8

Molecular formula:

Nb2O5

IUPAC Name:

diniobium pentoxide

Test material form:

solid: nanoform, surface-treated

Test animals / tissue source

Species:

cattle

Strain:

not specified

Details on test animals or tissues and environmental conditions:

Eyes from adult cattle (typically 12 to 60 months old) were obtained from a local abattoir as a by-product from freshly slaughtered animals. The eyes were excised by an abattoir employee after slaughter, and were placed in Hanks’ Balanced Salt Solution (HBSS) supplemented with antibiotics (penicillin at 100 IU/mL and streptomycin at 100 μg/mL). They were transported to the test facility over ice packs on the same day of slaughter. The corneas were prepared immediately on arrival.

Test system

Vehicle:

physiological saline

Controls:

yes, concurrent vehicle

yes, concurrent positive control

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.75 mL
- Concentration (if solution): 20% w/v solution in sodium chloride 0.9% w/v.

Duration of treatment / exposure:

240 minutes

Duration of post- treatment incubation (in vitro):

Not applicable

Number of animals or in vitro replicates:

Three corneas

Details on study design:

SELECTION AND PREPARATION OF CORNEAS
The medium from both chambers of each holder was replaced with fresh complete EMEM. A pre-treatment opacity reading was taken for each cornea using a calibrated opacitometer. Three corneas were randomly allocated to the negative control. Three corneas were also allocated to the test item and three corneas to the positive control item.

NUMBER OF REPLICATES
Triplicate

NEGATIVE CONTROL USED
Sodium chloride 0.9% w/v

POSITIVE CONTROL USED
Imidazole

APPLICATION DOSE AND EXPOSURE TIME
The EMEM was removed from the anterior chamber of the BCOP holder and 0.75 mL of the test item preparation or control items were applied to the appropriate corneas. The holders were gently tilted back and forth to ensure a uniform application of the item over the entire cornea. Each holder was incubated, anterior chamber uppermost, at 32 ± 1 ºC for 240 minutes.

POST-INCUBATION PERIOD: no.

REMOVAL OF TEST SUBSTANCE
- Number of washing steps after exposure period: At least three.

METHODS FOR MEASURED ENDPOINTS:
- Corneal opacity: A post-treatment opacity reading was taken and each cornea was visually observed.
- Corneal permeability: passage of sodium fluorescein dye measured with the aid of microtiter plate reader (OD492)

SCORING SYSTEM: In Vitro Irritancy Score (IVIS)

DECISION CRITERIA: Decision criteria as indicated in the TG.

Results and discussion

In vitro

Results

Irritation parameter:

in vitro irritation score

Run / experiment:

Mean

Value:

18

Vehicle controls validity:

valid

Negative controls validity:

not applicable

Positive controls validity:

valid

Other effects / acceptance of results:

OTHER EFFECTS:
- Visible damage on test system: The corneas treated with the test item were clear post treatment, with some test item remaining on the cornea.


ACCEPTANCE OF RESULTS:
- Acceptance criteria met for negative control: The negative control gave opacity of ≤2.4 and permeability ≤0.072. The negative control acceptance criteria were therefore satisfied.
- Acceptance criteria met for positive control: The positive control In Vitro Irritancy Score was within the range of 65.1 to 123.3. The positive control acceptance criterion was therefore satisfied.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Calcium Titanium Trioxide produced an IVIS of 0.8 during an in vitro eye irritation study. No prediction can be made in regards to its classification as irritant or damaging to the eye.

Executive summary:

An in vitro Bovine Corneal Opacity and Permeability (BCOP) assay was performed in line with OECD Testing Guideline 437 (Bovine Corneal Opacity and Permeability Test Method). The study was GLP-compliant.

A solution of 20% w/v test material in sodium chloride 0.9% w/v was applied to three cattle corneas obtained from an abattoir at a volume of 0.75 mL, after which each cornea was incubated at 32±1°C for 240 minutes. Opacity and permeability of corneas were measured following exposition.

Negative and positive controls were performed and considered as valid.

An In Vitro Irritation Score (IVIS) of 18.0 was calculated for Calcium Titanium Trioxide from corneal opacity and permeability measurements. The substance is not irritant to the eye according to the guideline.

Since the result is between 3 and 55 no prediction can be made regarding the classification of Calcium Titanium Trioxide as irritant or damaging to the eye in accordance with with Regulation (EC) No.1272/2008.