Barium europium strontium silicate

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

August 24, 2011 - August 26, 2011

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2011

Report date:

2011

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

2009

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

2010

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

other: Skinethic Skin irritation test -42bis Standard operating procedure (SOP) 2009

Version / remarks:

2009

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

barium(2+) strontium(2+) λ¹-europium(1+) silicate

EC Number:

620-318-9

Cas Number:

1003049-92-0

Molecular formula:

Ba2-x-ySrxEuySiO4 (0.15

IUPAC Name:

barium(2+) strontium(2+) λ¹-europium(1+) silicate

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
- Tissue batch number(s): 11 022A 0802
- Date of initiation of testing: August 24, 2011

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 PBS using a multi pipette


MTT DYE USED TO MEASURE TISSUE VIABILITY AFTER TREATMENT / EXPOSURE
- MTT concentration: 1 mg/mL
- Incubation time: 3 hours
- Spectrophotometer: spectrophotometer
- Wavelength: 570 nm

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

Duration of post-treatment incubation (if applicable):

42 hours

Number of replicates:

3

Results and discussion

In vitro

Results

Results 1

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

Tissue 1/experiment 1

Value:

1.681

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:

1.79

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:

1.798

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: no

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

Any other information on results incl. tables

Results

Dose group  treatment interval  optical density tissue1  optical density tissue 2  optical density tissue 3  MEAN optical density  mean relative viability [%] Standard deviation   negative control  42 min  1.768  1.598  1.878  1.748  100  8.06  positive control  42 min  0.057  0.049  0.057  0.054  3.11  8.32  test item  42 min  1.681  1.790  1.798  1.756  100.47  3.74

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The test substance is to be considered as non-irritating to the skin under the conditions of this experiment.

Executive summary:

In an in vitro skin irritation model, substance was tested. The applied cellline (RHE (Reconstructed Human Epidermis) is produced by SkinEthic by culturing human adult keratinocytes on a polycarbonate filter in such a quality that a functional stratum corneum is available and thermal differentation takes place. The test was conducted under GLP and according to OECD guideline 439, the EU Method B.46 and the Standard Operating Procedure of SkinEthic's (Skin irritation test -42bis).

Each test is performed in triplicates. 16µl of controls were directly applied to the tissue. Prior 16mg of test substance were applied, 10 µl of water were sprayed to the tissue. After treatment of (treatment time 42minutes at roomtemperature) substances were removed and tissues were incubated for 424 hours.

For testing validity of the Skin model, a positive control (5% sodiumdodecylsulfate in deionized water) and a negative control (PBS buffer) were used.

After topical exposure of test substance, positive control, or negative control cell viability is measured in a MTT assay. In this assay cell viability is measured by conversion of MTT to a formazan salt by a dehydrogenase enzyme.

As the test item has a very high cell viability of (100%) passing the threshold value of 50%, this item is to be considered as non-irritant. The test is valid since the criteria for the positive control (cell viability < 40%; 3,1% in this test) and the negative control (optical density between 1.2 and 2.5; 1.75 in this itest) are met.