(4-carboxybutyl)triphenylphosphonium bromide

Skin irritation / corrosion

Administrative data

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

22 Jan - 13 Feb 2020

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2020

Report date:

2020

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

Updated Guideline adopted July 29, 2016

Deviations:

yes

Remarks:

In Step 1 of the test for colour interference the incubation time of the mixture with test item and isopropanol was 1 hour instead of 2-3 hours. This deviation was considered to have not affected the integrity or validity of the study.

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

(4-carboxybutyl)triphenylphosphonium bromide

EC Number:

241-782-5

EC Name:

(4-carboxybutyl)triphenylphosphonium bromide

Cas Number:

17814-85-6

Molecular formula:

C23H24BrO2P

IUPAC Name:

(4-carboxybutyl)triphenylphosphonium bromide

Test material form:

solid: crystalline

In vitro test system

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Cell source:

other: not reported

Vehicle:

unchanged (no vehicle)

Remarks:

25 μL of deionised water were applied onto the surface of duplicate EpiDerm™ tissue

Details on test system:

RECONSTRUCTED HUMAN EPIDERMIS (RHE) TISSUE
- Model used: EpiDerm™
- Tissue lot number: 30847
- Delivery date: 11 February 2020
- Date of initiation of testing: 13 February 2020

TEMPERATURE USED FOR TEST SYSTEM
- Temperature used during treatment / exposure: 37 ± 1.5 °C

REMOVAL OF TEST MATERIAL AND CONTROLS
- Number of washing steps: 20
- Observable damage in the tissue due to washing: none
- Modifications to validated SOP: none

MTT DYE USED TO MEASURE TISSUE VIABILITY AFTER TREATMENT / EXPOSURE
- MTT concentration: 1 mg/mL
- Incubation time: 3 h
- Spectrophotometer: microplate reader (Versamax®, Molecular Devices, SoftMax Pro Enterprise (version 4.7.1))
- Wavelength: 570 nm
- Filter: none

FUNCTIONAL MODEL CONDITIONS WITH REFERENCE TO HISTORICAL DATA
- Viability:
Specification: MTT QC assay, 4 h, n= 3
Acceptance criteria: OD (540-570 nm) <1.0 - 3.0>
Result and QA Statement: 1.968 ± 0.158 (Pass)

- Barrier function:
Specification: ET-50 assay, 100 µL 1% Triton X-100, 4 time points, n = 3, MTT assay
Acceptance criteria: ET-50 <5.77 - 8.72 h>
Result and QA Statement: 5.05 h (Pass)

- Morphology: Tissue viability and the barrier function test are within the acceptable ranges and indicate appropriate formation of the epidermal barrier, the presence of a functional stratum corneum, a viable basal cell layer, and intermediate spinous and granular layers.

- Contamination:
Specification: Long-term antibiotic and antimycotic free culture
Acceptance criteria: No contamination
Result and QA Statement: Sterile (Pass)

NUMBER OF REPLICATE TISSUES: 2

NUMBER OF INDEPENDENT TEST SEQUENCES / EXPERIMENTS TO DERIVE FINAL PREDICTION: 1

PREDICTION MODEL / DECISION CRITERIA
- The test substance is considered to be corrosive to skin if the viability after 3 minutes exposure is less than 50%, or if the viability after 3 minutes exposure is greater than or equal to 50 % and the viability after 1 hour exposure is less than 15%.
- The test substance is considered to be non-corrosive to skin if the viability after 3 minutes exposure is greater than or equal to 50% and the viability after 1 hour exposure is greater than or equal to 15%.

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

TEST MATERIAL
- Amount(s) applied: 25 ± 2 mg

NEGATIVE CONTROL
- Amount(s) applied: 50 μL Dulbecco's Phosphate-Buffered Saline (DPBS) (MatTek), Batch 112719 ISE

POSITIVE CONTROL
- Amount(s) applied: 50 μL 8.0 N Potassium Hydroxide (KOH, Honeywell), Batch H3410

Duration of treatment / exposure:

3 and 60 min

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 min exposure, mean of 2 replicates

Value:

100.72

Vehicle controls validity:

not examined

Negative controls validity:

valid

Remarks:

100% tissue viability

Positive controls validity:

valid

Remarks:

12.65% tissue viability

Remarks on result:

no indication of irritation

Results 2

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

60 min exposure, mean of 2 replicates

Value:

24.58

Vehicle controls validity:

not examined

Negative controls validity:

valid

Remarks:

100% tissue viability

Positive controls validity:

valid

Remarks:

1.75% tissue viability

Remarks on result:

no indication of irritation

Other effects / acceptance of results:

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

DEMONSTRATION OF TECHNICAL PROFICIENCY: The test facility has been certified to demonstrate proficiency in the EpiDerm Skin Corrosion Test (OECD TG 431) by
- correct prediction of the corrosive potential of the proficiency chemicals
- correct assignment of the chemicals into the sub-classes of corrosiveness as defined by the OECD TG 431 (i.e. 1A vs 1BC merged)

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 test item is considered to be non-corrosive to skin according to EU CLP and UN GHS.