Phosphoric acid, mono C16-20 (branched, even numbered) alkyl esters

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

July 2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2015

Report date:

2015

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 431 (In Vitro Skin Corrosion: Human Skin Model Test)

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:

Phosphoric acid, mono C16-20 (branched, even numbered) alkyl esters

Molecular formula:

unspecified

IUPAC Name:

Phosphoric acid, mono C16-20 (branched, even numbered) alkyl esters

Test material form:

liquid: viscous

Details on test material:

- Name as cited in the report: SAT150011
- Chemical name: Phosphoric acid, mono C16-20 (branched, even numbered) alkyl esters
- Batch No.: RP GW 915 MU
- Storage Conditions: room temperature
- Expiration date: March/April 2016
- Description: clear, light amber, viscous liquid
- Molecular weight: approx. 340 Da
- Purity: 73.8 % Mono- and Diester (NMR)

In vitro test system

Test system:

human skin model

Remarks:

EpiSkin-SM (TM)

Source species:

human

Cell type:

non-transformed keratinocytes

Cell source:

skin obtained from plastic surgery from multiple donors

Source strain:

not specified

Vehicle:

unchanged (no vehicle)

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

The test item was applied undiluted. 50 ± 3 µL (131.6 µL/cm2) of the test item was dispensed directly atop the EPISKIN-SM (TM) tissue using a positive displacement pipette. The test item was spread to match size of the tissue.

Duration of treatment / exposure:

4 h

Duration of post-treatment incubation (if applicable):

3 h MTT incubation

Number of replicates:

duplicate cultures per test

Results and discussion

In vitro

Results

Results 1

Irritation / corrosion parameter:

% tissue viability

Remarks:

relative

Run / experiment:

Mean 3 min treatment

Value:

85

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Remarks:

100.0

Positive controls validity:

not applicable

Results 2

Irritation / corrosion parameter:

% tissue viability

Remarks:

realtive

Run / experiment:

Mean 60 min treatment

Value:

65

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Remarks:

100.0

Positive controls validity:

not applicable

Results 3

Irritation / corrosion parameter:

% tissue viability

Remarks:

relative

Run / experiment:

Mean 4h treatment

Value:

94

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Remarks:

100.0

Positive controls validity:

valid

Remarks:

5.0

Any other information on results incl. tables

PRE-EXPERIMENTS

The mixture of 50 µL test item per 2 mL MTT medium showed no reduction of MTT as compared to the solvent. The mixture did not turn blue/purple. Therefore, NSMTT equaled 0%.

The mixtures of 10 µL test item per 90 µL A. dest. and per 90 µL isopropanol showed no colouring as compared to the solvent. Therefore NSC equaled 0%.

TEST RESULTS

The test item showed no non-specific MTT-reducing or water-colouring potential, therefore no additional controls were necessary.

The test item showed no corrosive effects. The mean relative tissue viability (% negative control) was >= 35% (94%) after 4 h treatment.

Relative mean tissue viability was reduced to 65% after 60 min treatment and to 85% after 3 min treatment.

The controls confirmed the validity of the study. The mean OD570 of the two negative control tissues was between 0.6 and 1.5 for each exposure period. The mean relative tissue viability (% negative control) of the positive control was <= 20% (5%) after 4 h treatment. The maximum inter tissue viability difference of replicate tissues of all dose groups was <= 30% (0.2% - 7.8%).

3 MIN EXPERIMENT	Negative Control	Test Item	Positive Control
total mean OD570 (mean 2 replicates, blank corrected)	0.774	0.659	n.a.
mean rel. tissue viability [%]	100	85	n.a.
mean inter tissue viability diff. [%]	0.2	7.8	n.a.

60 MIN EXPERIMENT	Negative Control	Test Item	Positive Control
total mean OD570 (mean 2 replicates, blank corrected)	0.857	0.560	n.a.
mean rel. tissue viability [%]	100	65	n.a.
mean inter tissue viability diff. [%]	1.9	5.6	n.a.

4 h EXPERIMENT	Negative Control	Test Item	Positive Control
total mean OD570 (mean 2 replicates, blank corrected)	0.610	0.576	0.030
mean rel. tissue viability [%]	100	94	5
mean inter tissue viability diff. [%]	3.4	2.9	1.3

Applicant's summary and conclusion

Interpretation of results:

other: not corrosive

Remarks:

Criteria used for interpretation of results: other: OECD 431

Conclusions:

In this study under the given conditions the test item showed no corrosive effects. The relative mean tissue viability after 4 h treatment was not decreased to less than 35% of the corresponding negative control tissues. The test item is therefore classified as "non-corrosive".

Executive summary:

In Ihe present study the skin corrosivity potential of SAT150011 was analysed. Since corrosive chemicals are cytotoxic after topical short-time exposure to Ihe EPISKIN-SM(TM), a reconstituted three-dimensional human epidermis model, the cytotoxic effects of the test item were determined.

Cytotoxicity is expressed as the reduction of mitochondrial dehydrogenase aclivity measured by formazan production from MTT after a 3 min, 60 min and 4 h exposure period and compared to those of the concurrent negative controls.

In this study under the given conditions the test item showed no corrosive effects. The relative mean tissue viability after 4 h treatment was not decreased to less than 35% of the corresponding negative control tissues. The test item is therefore classified as "non-corrosive".