Lecithins, hydrogenated

Eye irritation

Administrative data

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

December 2019

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:

Lecithins, hydrogenated

EC Number:

295-786-7

EC Name:

Lecithins, hydrogenated

Cas Number:

92128-87-5

Molecular formula:

not applicable - UVCB substance

IUPAC Name:

Lecithins, hydrogenated

Specific details on test material used for the study:

Description:
Pale yellow powder

Storage conditions:
At room temperature
Protected from light
Protected from humidity

Specific requirements (handling conditions):
None

Purity:
Considered as 100 % (UVCB substance)

Test animals / tissue source

Species:

human

Strain:

not specified

Details on test animals or tissues and environmental conditions:

Species: Reconstructed human Cornea-like Epithelium (tissues).
Supplier: MatTek, Bratislava, Slovak Republic.
Selection: at receipt, the tissues were inspected for obvious defects prior to use, as they could have been rejected based on blistering, excess fluid or air bubbles below the tissue insert.
Storage conditions: at receipt, the living EpiOcular™ tissues were stored as described in the § Pre incubation of the tissues.
Description: the EpiOcularTM model consists of an airlifted, living, multilayered ocular tissue construction (surface 0.60 cm2), reconstructed from normal (non-transformed) human-derived keratinocytes. This is a non-keratinized epithelium which models the cornea epithelium with progressively stratified, but not cornified cells. The 3D tissue consists of highly organized cell layers similar to that found in the cornea. The model features a normal ultra-structure and is functionally equivalent to human in vivo tissue.
Expiry date: the EpiOcular tissues were used within 72 hours of their production.

Test system

Vehicle:

unchanged (no vehicle)

Controls:

yes, concurrent positive control

yes, concurrent negative control

Amount / concentration applied:

As the test item was a solid, a quantity of 51 mg (± 1 mg) was weighed in order to evenly apply 50 mg (± 2 mg) of test item to the surface of each tissue using a micro spatula/spoon, taking care to spread it over the whole tissue surface area without damaging the tissue sample.

For the negative and positive controls, since they could be sampled using a pipette, a volume of 50 µL of each item was evenly applied to the surface of each dedicated tissue, taking care to spread them over the whole tissue surface area without damaging the tissue sample.

Duration of treatment / exposure:

Following the pre-incubation period, the tissues were pre-wetted with 20 µL of D-PBS. The plate was tapped to ensure that the entire tissue surface was wetted. The tissues were then incubated at +37°C, 5% CO2 in a humidified incubator for 30 minutes (± 2 minutes).

Then, all items (test item, negative and positive controls) were applied topically on each designated tissue, and gently spread onto the epithelium surface to ensure uniform covering of the tissue. As the test item was a solid, the insert was removed from the medium and placed onto a sterile surface (e.g. the lid of a microtiter plate) to avoid that test item was spilled into the assay medium under the tissue insert. The test item was then applied by pouring it onto the tissue surface so that the surface was completely covered by the test item. Inserts were tapped on the wall/well of the plate to ensure that the items were correctly spread across the entire surface of each tissue. All tissues were then placed back into the assay medium and incubated at +37°C, 5% CO2 in a humidified incubator for 6 hours (± 15 minutes).

The tissues were processed (treatment and rinsing) in the same order and at regular time intervals to ensure each tissue receives an equal exposure period.

Duration of post- treatment incubation (in vitro):

At the end of the treatment period, each tissue was removed from the well of the treatment plate and rinsed to gently remove any residual test or control items. A set of three clean beakers containing a minimum of 100 mL each of D-PBS was used per test or control item. The test or control items were firstly removed from the tissue surface by tapping upside down each insert onto a clean absorbent paper. The tissues were then dipped into the first beaker of D-PBS, swirled in a circular motion during approximately 2 seconds, lifted out and decanted back into the beaker. This process was performed three times per beaker. Any remaining liquid was decanted onto an absorbent paper.

Number of animals or in vitro replicates:

two tissue replicates tested with test item
two tissue replicates tested with positive control
two tissue replicates tested with negative control

Details on study design:

MAIN TEST:
One 6-well plate was used for each item.
Test item and both negative and positive controls were applied on duplicate tissues.

1. Pre-incubation of the tissues As the tissues were shipped the day before the treatment, tissues were equilibrated (in the 24-well shipping container) to room temperature for at least 15 minutes, at receipt. Each tissue was inspected as specified in internal procedure, removed from the 24‐well shipping containers and placed in a 6-well plate containing 1 mL of pre-warmed assay medium. Tissues were then incubated for 1 hour at +37°C, 5% CO2 in a humidified incubator. After the pre-incubation period, the assay medium was removed and replaced by 1 mL of fresh assay medium before incubation overnight (16-24h) at +37°C, 5% CO2 in a humidified incubator.
Each 6-well plate was labeled with the test item or control codes.

2. Treatment of tissues
Following the pre-incubation period, the tissues were pre-wetted with 20 μL of D-PBS. The plate was tapped to ensure that the entire tissue surface was wetted. The tissues were then incubated at +37°C, 5% CO2 in a humidified incubator for 30 minutes (± 2 minutes).
Then, all items (test item, negative and positive controls) were applied topically on each designated tissue, and gently spread onto the epithelium surface to ensure uniform covering of the tissue. As the test item was a solid, the insert was removed from the medium and placed onto a sterile surface (e.g. the lid of a microtiter plate) to avoid that test item was spilled into the assay medium under the tissue insert. The test item was then applied by pouring it onto the tissue surface so that the surface was completely covered by the test item. Inserts were tapped on the wall/well of the plate to ensure that the items were correctly spread across the entire surface of each tissue. All tissues were then placed back into the assay medium and incubated at +37°C, 5% CO2 in a humidified incubator for 6 hours (± 15 minutes).
The tissues were processed (treatment and rinsing) in the same order and at regular time-intervals to ensure each tissue receives an equal exposure period.

3. Rinsing of tissues
At the end of the treatment period, each tissue was removed from the well of the treatment plate and rinsed to gently remove any residual test or control items. A set of three clean beakers containing a minimum of 100 mL each of D-PBS was used per test or control item. The test or control items were firstly removed from the tissue surface by tapping upside down each insert onto a clean absorbent paper. The tissues were
then dipped into the first beaker of D-PBS, swirled in a circular motion during approximately 2 seconds, lifted out and decanted back into the beaker. This process was performed three times per beaker. Any
remaining liquid was decanted onto an absorbent paper.

4. Post-soak and post-incubation
The rinsed tissues were transferred to new wells of a pre-labeled 12-well plate containing 5 mL of assay medium (pre-warmed at room temperature) and were then incubated for 25 minutes (± 2 minutes) at room temperature. This incubation in assay medium was intended to remove any test article from the tissue.
At the end of the post-soak immersion, inserts were blotted on absorbent material and transferred to appropriate well of the pre-labeled 6-well plate containing 1 mL of assay medium. The tissues were then
incubated for 18 hours (± 15 minutes) at +37°C, 5% CO2 in a humidified incubator.

Results and discussion

In vitro

Results

Irritation parameter:

other: relative viability (%)

Run / experiment:

mean

Value:

ca. 95

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Executive summary:

Under the experimental conditions of this study (OECD 492 guideline), the test item is considered to be non-irritant to Reconstructed human Cornea-like Epithelium.Accordingly, the classification of the test item should be No Category (GHS 2017 and Regulation No. 1272/2008/EEC).