Di(tetraethylammonium)hexahydroxoplatinate(IV)

Skin irritation / corrosion

Administrative data

Endpoint:

skin corrosion: 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

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 431 (In Vitro Skin Corrosion: Reconstructed Human Epidermis (RHE) Test Method)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.40 (In Vitro Skin Corrosion: Transcutaneous Electrical Resistance Test (TER))

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

platinumhexol; bis(tetrapropylazanium)

EC Number:

848-537-7

Cas Number:

1912392-88-1

Molecular formula:

C16H46N2O6Pt

IUPAC Name:

platinumhexol; bis(tetrapropylazanium)

Test material form:

liquid

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch number of test material: 3341/00-F9
- Expiration date of the lot/batch: September 10, 2020
- Purity test date: Certificate of analysis dated September 09, 2019
- Content: 10.94 % Pt
- Form: liquid
- Appearance: amber liquid

In vitro test system

Test system:

human skin model

Source species:

other:

Cell type:

non-transformed keratinocytes

Cell source:

other: EpiDermTM (EPI-200-SCT, lot no. 30830) MatTek In Vitro Life Sciences Laboratories

Source strain:

other: Reconstructed human epidermis model

Details on animal used as source of test system:

not applicable

Justification for test system used:

no data

Vehicle:

unchanged (no vehicle)

Details on test system:

EpiDerm is a three-dimensional reconstructed human epidermis model, comprised of non-transformed, human-derived epidermal keratinocytes, which have been cultured to form a multi-layered, highly differentiated model of the human epidermis. It consists of organized basal, spinous and granular layers, and a multi-layered stratum corneum containing intercellular lamellar lipid layers representing main lipid classes analogous to those found in vivo
The test method is based on the premise that corrosive chemicals are able to penetrate the stratum corneum by diffusion or erosion, and are cytotoxic to the cells in the underlying layers. Cell viability is measured by enzymatic conversion of the vital dye MTT into a blue/purple formazan salt that is
quantitative measured after extraction from tissues. Corrosive materials are identified by their ability to decrease cell viability below defined threshold levels.
The test method is based on the SOP MK-24-007-0024 of the validated and regulatory accepted EpidermTM SCT.

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

- Amount(s) applied (volume or weight with unit): 50 μL of undiluted test item were applied to the skin model. Two replicate tissues for each treatment (exposure periods) were employed. At the end of the exposure period, the test item was carefully washed from the skin surface with Dulbecco's phosphate buffered saline (DPBS).

NEGATIVE CONTROL
- Amount(s) applied (volume or weight): 50 μL sterile water was added to each of the two negative control skin units.

POSITIVE CONTROL
- Amount(s) applied (volume or weight): 50 μL KOH was added to each of the two positive control skin units.
- Concentration (if solution): 8N solution

Duration of treatment / exposure:

3 minutes or 1 hour (37°C, 5% CO2 and 95% humidity)

Duration of post-treatment incubation (if applicable):

not applicable

Number of replicates:

2

Results and discussion

In vitro

Results

Results 1

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

3 minute exposure period

Value:

28

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Remarks:

the mean OD of the negative control of 2 tissues was 1.867 and well within the acceptable range of >0.8 to < 2.8

Positive controls validity:

valid

Remarks:

the viability of cells treated with the positive reference item 8.0N KOH was 4.4% of the negative control

Remarks on result:

other: corrosive

Remarks:

Mean relative viability < 50% and > 25% after 3 min exposure, the test item is considered to be corrosive to skin sub-categories 1B and 1C

Results 2

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

60 minute exposure period

Value:

6.1

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Remarks:

the mean OD of the negative control of 2 tissues was 1.873 and well within the acceptable range of >0.8 to < 2.8

Positive controls validity:

valid

Remarks:

the viability of cells treated with the positive reference item 8.0N KOH was 4.3% of the negative control and well below the 15 cut-off value at the 60-minute exposure

Remarks on result:

other: corrosive

Remarks:

mean relative viability < 15% (60-minute exposure), the test substance is considered to be corrosive to skin

Other effects / acceptance of results:

The standard deviation of all replicates determined (at 20-100% viability) was below the limit of acceptance of 30%. Hence, all acceptance criteria were fulfilled.

Any other information on results incl. tables

The MTT solution containing the test item did not turn blue/purple. This was taken to indicate the test item did not reduce MTT.

The solution containing the test item was a yellow color, therefore additional color correction tissues were incorporated into the testing procedure. However, the results obtained showed that no color interference occurred. It was therefore considered unnecessary to use the results of the color correction tissues for quantitative correction of results or for reporting purposes.

The relative mean viabilities for each treatment group were as follows:

Exposure Period	Percentage Viability
	Negative Control	Positive Control	Test Item
3 minute	100*	4.4	28.0
60 minute	100*	4.3	6.1

*The mean viability of the negative control tissues is set at 100%

*The mean viability of the negative control tissues is set at 100%

Applicant's summary and conclusion

Interpretation of results:

other: sub-category 1B and 1C since this test cannot resolve between the two

Conclusions:

In an in vitro EpiDerm assay conducted in accordance with OECD guideline 431 and to GLP, Di(tetraethylammonium)hexahydroxoplatinate(IV) (aqueous solution) was corrosive to skin and classified as sub-category 1B-and-1C.

Executive summary:

Di(tetraethylammonium)hexahydroxoplatinate(IV) (aqueous solution) was tested for skin corrosivity potential in an in vitro EpiDerm assay conducted in accordance with OECD guideline 431 and to GLP.

Cell viability was quantitatively measured using the MTT reduction assay with optical density being expressed as a relative percentage of that of the negative control. The mean cell viability following exposure to the test substance was calculated to be greater than25% (28% of the negative controls) after a 3-minute exposure and less than 15% (6.1% of the negative controls) after a 1-hour exposure, and it was therefore considered to be corrosive to skin.

Under the conditions of this assay, Di(tetraethylammonium)hexahydroxoplatinate(IV) (aqueous solution)did not meet the criteria for classification as corrosive category 1A under GHS classification criteria but would be classified as sub-category 1B-and-1C.

Based on the results of this study, the test item should be classified as corrosive to the skin (category 1B) according to EU CLP criteria (EC 1272/2008).