Hexanoic acid, 3,5,5-trimethyl-, tin(2+) salt (2:1)

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2010-11-24 to 2010-11-26

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2011

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

tin(2+) bis(3,5,5-trimethylhexanoate)

EC Number:

700-567-0

Cas Number:

1231728-34-9

Molecular formula:

C18H34O4Sn

IUPAC Name:

tin(2+) bis(3,5,5-trimethylhexanoate)

Test material form:

liquid: viscous

Test animals

Species:

other: reconstructed human epidermis model EpiDerm™ (EPI-200-SIT)

Details on test animals or test system and environmental conditions:

EpiDerm™ is cultured from normal human keratinocytes on inert polycarbonate filters.

Test system

Amount / concentration applied:

30 µl

Duration of treatment / exposure:

Quality control 2 h (± 15 min) (Triton X-100, 1 % solution)
Positive control 60 min (± 1 min) (SDS 5 % solution)
Negative control 60 min (± 1 min) Ultra Pure Water
Test substance 60 min (± 1 min) undiluted

Observation period:

after washing process post incubation period of 42 h

Number of animals:

The test was performed in triplicate

Results and discussion

In vivo

Irritant / corrosive response data:

Test substance: mean viability 84.1 (+/- 7.2) %
Negative control: mean viability 100 (+/- 1.2) %
Positive control: mean viability 7.8 (+/- 1.3) %

Any other information on results incl. tables

Test substance: mean viability 84.1 (+/- 7.2) %

Negative control: mean viability 100 (+/- 1.2) %

Positive control: mean viability 7.8 (+/- 1.3) %

Applicant's summary and conclusion

Interpretation of results:

not irritating

Remarks:

Migrated information Criteria used for interpretation of results: expert judgment

Conclusions:

Topical application of the test substance on top of the stratum corneum of the reconstructed human epidermis model EpiDerm™ (in triplicate)
resulted in a mean cell viability of 84.1 % when compared to the corresponding negative conrol. According to the evaluation scheme of OECD test
guideline 439 the test substance has to be predicted as not irritating to the skin.

Executive summary:

The skin irritating potential of the test substance hexanoic acid, 3,5,5-trimethyl-, tin (2+)salt (2:1) has been investigated using an in-vitro reconstructed human epidermal model (RHE), according to OECD guideline 439 (In Vitro Skin Irritation: Reconstructed Human Epidermis Test Method, July 2010).

EpiDerm™ RHEs were topically exposed to 30µL of the test substance for 60 min (± 1 min). The cell viability was determined after an additional 42 h (± 2 h) post incubation period. For the analysis of the tissue viability the Standard MTT Assay was used. The viability of the negative control (UPW) was set to 100%.

The topical application of the test substance to stratum corneum of the RHE (each in triplicate) resulted in a mean cell viability of 84.1% related to the corresponding negative control.

Residual test substance adhered to the reconstructed epidermis after completion of the rinsing procedure may have had an impact on the overall test performance due to the chemically reducing properties of the test substance towards the MTT reagent. A control with freeze killed tissue, to identify possible interference, was not included in this study. However, according to the study authors the validity of the study was not affected.

The functionality of the used test system was demonstrated by topical application of Triton X-100 (1% aqueous solution) in a quality control, resulting in a mean cell viability of 95.5 % after 2 h (± 15 min) exposure. The sensitivity and accuracy of the used test system has been demonstrated with the reference substance SDS (5% aqueous solution). A mean cell viability of 7.8 % in relation to the corresponding negative control UPW was determined.

 

In conclusion hexanoic acid, 3,5,5-trimethyl-, tin (2+)salt (2:1) has to be predicted as not irritating to skin when the current prediction model is applied according to the international OECD Test Guideline 439.