Iron citrate

Eye irritation

Administrative data

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2019

Report date:

2019

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 492 (Reconstructed Human Cornea-like Epithelium (RhCE) Test Method for Identifying Chemicals Not Requiring Classification and Labelling for Eye Irritation or Serious Eye Damage)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Iron citrate

EC Number:

219-045-4

EC Name:

Iron citrate

Cas Number:

2338-05-8

Molecular formula:

C6H8O7.xFe

IUPAC Name:

iron citrate

Specific details on test material used for the study:

Name Ferric citrate monohydrate
Batch no. 45882
Appearance red to brown solid powder
Composition Ferric Citrate
Purity 99.81%
Homogeneity homogeneous
Expiry date 18. May 2019
Storage Room temperature (20 ± 5 °C); Keep away from light

Test animals / tissue source

Species:

human

Strain:

other: The EpiOcularTM tissue consists of normal, human-derived keratinocytes which have been cultured to form a stratified squamous epithelium similar to that found in the human cornea.

Test system

Vehicle:

unchanged (no vehicle)

Controls:

yes, concurrent positive control

yes, concurrent negative control

Amount / concentration applied:

Approx 50 mg of test material

Duration of treatment / exposure:

After overnight incubation, the tissues were pre-wetted with 20 μL DPBS buffer and the tissues were incubated at 37 ± 1 °C, 5 ± 1 % CO2 and ≥ 95% relative humidity for 29 minutes. After that, 50 μL of the controls and a defined amount of the test item were applied in duplicate in one- minute- intervals.
After dosing the last tissue, all plates were transferred into the incubator for 6 hours at 37 ± 1 °C, 5 ± 1 % CO2 and ≥ 95% relative humidity

Duration of post- treatment incubation (in vitro):

At the end of exposure time, the inserts were removed from the plates in one-minute-intervals using sterile forceps and rinsed immediately. The inserts were thoroughly rinsed with DPBS. Then, the tissues were immediately transferred into 5 mL of assay medium in pre-labelled 12-well plate for 25 minutes post soak at room temperature.
After that, each insert was blotted on absorbent material and transferred into a pre-labelled 6-well plate, containing 1 mL assay medium. For post-treatment incubation, the tissues were incubated for 18 hours and 15 minutes at 37 ± 1 °C, 5 ± 1 % CO2 and ≥ 95% relative humidity.

Number of animals or in vitro replicates:

Duplicates

Results and discussion

In vitro

Results

Results 1

Irritation parameter:

other: % tissue viability

Run / experiment:

1

Value:

27.6

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

positive indication of irritation

Results 2

Irritation parameter:

other: % tissue viability

Run / experiment:

2

Value:

24.4

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

positive indication of irritation

Other effects / acceptance of results:

After treatment with the test item, the mean value of relative tissue viability was reduced to 26.0 %. This value is below the threshold for eye irritation potential (≤ 60%).
All validity criteria were met. The criterion for optical density of the negative control was fulfilled: The OD value was 1.6 (> 0.8 and < 2.5).
The positive control induced a decrease in tissue viability as compared to the negative control to 39.5%. Variation within the replicates of the controls and the test item was acceptable (< 20%).
For these reasons, the result of the test is considered valid.

Any other information on results incl. tables

Mean % tissue viability for the positive control (methyl acetate, which is eye irritant Cat 2) was measured at 39.5%

Applicant's summary and conclusion

Interpretation of results:

study cannot be used for classification

Remarks:

Only indicative of eye irritation / damage

Conclusions:

After treatment with the test item, the mean value of relative tissue viability was 26.0 %.
This value is below the threshold for eye irritation potential (≤ 60%). Test items that induce values below the threshold are either eye irritant or inducing serious eye damage.
According to the OECD Guideline 492, the EpiOcularTM Eye Irritation Test does not allow discrimination between eye irritation/reversible effects on the eye (Category 2) and serious eye damage/irreversible effects on the eye (Category 1). For these purposes, further testing with other suitable test methods is required.
Under the conditions of the test, Ferric citrate monohydrate is considered either eye irritant or inducing serious eye damage in the EpiOcularTM Eye Irritation Test.
However, it has been assessed that ferric citrate should be classified as Eye Irrit. 2 without further testing, based on the fact that it is unlikely to be Eye Dam 1, when citric acid, as the parent acid, is only Eye Irrit 2