Aluminium cerium lutetium oxide

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

December 16, 2015 - December 18, 2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2016

Report date:

2016

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 439 (In Vitro Skin Irritation: Reconstructed Human Epidermis Test Method)

Version / remarks:

July 28, 2015

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.46 (In Vitro Skin Irritation: Reconstructed Human Epidermis Model Test)

Version / remarks:

2012

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

other: SkinEthic Skin Irritation Test (42bis) Standard Operating Procedure (SOP): Using the Reconstructed Human Epidermis (RHE) model, INVITTOX

Version / remarks:

2009

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

aluminium cerium lutetium oxide

EC Number:

942-299-9

Cas Number:

1279099-21-6

Molecular formula:

Lu2.8-2.99Ce0.01-0.2Al5O12

IUPAC Name:

aluminium cerium lutetium oxide

Test material form:

solid

In vitro test system

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Justification for test system used:

To reduce animal testing, this alternative in vitro method was used. The human skin RHE-model closely mimics the biochemical and physiological properties of the upper parts of the human skin, i.e the epidermis.

Vehicle:

unchanged (no vehicle)

Details on test system:

RECONSTRUCTED HUMAN EPIDERMIS (RHE) TISSUE
- Model used: SkinEthic™ RHE-model RHE/S/17
- Tissue batch number(s): 15-RHE-151
- Date of initiation of testing: December 16, 2015

TEMPERATURE USED FOR TEST SYSTEM
- Temperature used during treatment / exposure: room temperature
- Temperature of post-treatment incubation: 37°C

REMOVAL OF TEST MATERIAL AND CONTROLS
-Volume and number of washing steps: minimum volume of 25 mL DPBS using a pipene

MTT DYE USED TO MEASURE TISSUE VIABILITY AFTER TREATMENT / EXPOSURE
- MTT concentration: 1 mg/mL
- Incubation time: 3 hours
- Spectrophotometer: microplate reader (ELx800, BioTek Instruments GmbH)
- Wavelength: 570 nm

FUNCTIONAL MODEL CONDITIONS WITH REFERENCE TO HISTORICAL DATA
- Viability: OD 1.0 (Acceptance criteria: OD > 0.7)
- Barrier function: 5.4 h (Acceptance criteria: 4 h <= ET50 <= 10 h
- Morphology: 6.0 cell layers, absence of significant histological abnormalities, satisfactory (acceptance criteria: number of cell layers >= 4; absence of significant histological abnormalities; well differentiated epidermis consisting of basal, spinous, granular layers and a stratum corneum)

NUMBER OF REPLICATE TISSUES: 3

NUMBER OF INDEPENDENT TEST SEQUENCES / EXPERIMENTS TO DERIVE FINAL PREDICTION: One experiment in triplicate

PREDICTION MODEL / DECISION CRITERIA
- The test substance is considered to be irritant to skin if the viability after exposure is less than 50% or equal to 50 %.
- The test substance is considered to be non-irritant to skin if the viability after exposure is greater than 50%.

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

TEST MATERIAL
- Amount applied: 16 mg

NEGATIVE CONTROL
- Amount applied: 16 µL

POSITIVE CONTROL
- Amount applied: 16 µL

Duration of treatment / exposure:

42 minutes (+/- 1 minute)

Duration of post-treatment incubation (if applicable):

42 hours (+/- 1 hour)

Number of replicates:

3

Results and discussion

In vitro

Results

Results 1

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

Tissue 1/experiment 1

Value:

2.111

Vehicle controls validity:

not examined

Negative controls validity:

valid

Positive controls validity:

valid

Results 2

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

Tissue 2/experiment 1

Value:

2.004

Vehicle controls validity:

not examined

Negative controls validity:

valid

Positive controls validity:

valid

Results 3

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

Tissue 3/experiment 1

Value:

2.105

Vehicle controls validity:

not examined

Negative controls validity:

valid

Positive controls validity:

valid

Other effects / acceptance of results:

- OTHER EFFECTS:
- Visible damage on test system: no
- Direct-MTT reduction: none

ACCEPTANCE OF RESULTS:
- Acceptance criteria met for negative control: yes
- Acceptance criteria met for positive control: yes
- Acceptance criteria met for variability between replicate measurements: yes

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The tissue viability after treatment with the test item was higher than 50% (mean viability: 88.73%). Therefore, the test item is not considered to possess an irritant potential to skin.

Executive summary:

This in vitro study was performed to assess the irritation potential of the test item by means of the Reconstructed Human Epidermis (RHE) Test.

Triplicates of the human skin RHE-model were treated with the test item, the negative or the positive control for 42 minutes (± 1 minute). 16 μL of either the negative control (DPBS-buffer) or the positive control (5% aqueous solution of sodium dodecyl sulfate) were applied to the tissues. Before adding the solid test item, 10 μL of deionised water was spread to the epidermis surface to improve the contact between the test item and the epidermis. Afterwards, 16 mg of the test item were applied to the tissues.

After treatment with the negative control (DPBS-buffer) the mean OD was 2.074 (study acceptance criteria: > 1.423). Treatment with the positive control (5% aqueous solution of sodium dodecyl sulfate) revealed a mean viability value of 1.10% (study acceptance criteria: <3.42%).

Therefore, the study ful fi lled the validity criteria.

The tissue viability after treatment with the test item was 88.73% and, thus, higher than 50%, i.e. according to UN GHS classification the test item is considered to be  not irritanting to skin (UN GHS: No Category).