Esterification product of castor oil and tetrahydromethyl-1,3-isobenzofuranedione

Skin irritation / corrosion

Administrative data

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

June 2008

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2008

Report date:

2008

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Esterification product of castor oil and tetrahydromethyl-1,3-isobenzofuranedione

EC Number:

700-064-6

Cas Number:

2105830-60-0

Molecular formula:

Not applicable as this is a UVCB substance

IUPAC Name:

Esterification product of castor oil and tetrahydromethyl-1,3-isobenzofuranedione

Test material form:

liquid

Details on test material:

- Molecular weight: 2800-3000
- CAS Name: Castor oil, polymer with tetrahydromethyl-1,3-isobenzofurandione
- Description: Very viscous amber liquid
- Test substance storage: At room temperature in the dark under nitrogen
- Stebility under storage conditions: Stable
- Expiry date: 01 January 2009

In vitro test system

Test system:

human skin model

Remarks:

EpiDerm Skin Model (EPI-200)

Source species:

human

Cell type:

non-transformed keratinocytes

Cell source:

foreskin from a single donor

Source strain:

not specified

Justification for test system used:

Recommended test system in international guldelines (OECD and EC)

Vehicle:

water

Details on test system:

EpiDerm Skin Model (EPI-200, Lot no.: 10526 klt H).
The model consists of normal, human-derived epidermal keratinocytes which have been cultured to form a multilayered, hlghly differentiated model of the human epidermis. It consists of organlzed basal, spinous and granular layers, and a multi-Iayered stratum eomeum containing intercellular lamellar lipid layers arranged In patterns analogous to those found in vivo. The EpiDerm tissues (surface 0.6 cm2) were cultured on polycarbonate membranes of 10 mm cell culture inserts.

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

25 mg with 25 µl water

Duration of treatment / exposure:

3 min., 1 h

Number of replicates:

two tissues for a 3 min exposure
two tissues for a 1 h exposure

Results and discussion

In vitro

Results

Results 1

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

3 min. exposure

Value:

108

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Results 2

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

1 h exposure

Value:

108

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Other effects / acceptance of results:

no other effects

Any other information on results incl. tables

Mean tissue viability in the in vitro skin corrosion test with the Substance

	3 min application viability (percentage of control)	1 hr application viability (percentage of control)
Negative control	100	100
Test Substance	108	108
Positive control	5	4

The Table shows the mean tissue viability obtained after 3 minutes and 1 hour treatment with the Substance compared to the negative control tissues. Skin corrosion is expressed as the remaining cell viability after exposure to the test substance. The relative mean tissue viability obtained after 3 minutes and 1 hour treatment with the Substance compared to the negative control tissues was 108% at both exposure times. Since the mean relative tissue viability for the Substance was not below 50% after 3 minutes treatment and not below 15% after 1 hour treatment the Substance is considered to be not corrosive.

The absolute mean OD540 (optical density at 540 nm) of the negative control tissues was within the laboratory historical control data range. The mean relative tissue viability of the 3 minutes exposure of the positive control was 5%. The maximum inter tissue variability in viability between two tissues treated identically was less than 21% and the maximum difference in percentage between the mean viability of two tissues and one of the two tissues was less than 12%. It was therefore concluded that the test system functioned properly.

Applicant's summary and conclusion

Interpretation of results:

other: not corrosive

Conclusions:

It is concluded that this test is valid and that the Substance is not corrosive in the in vitro skin corrosion test under the experimental conditions described in this report.

Executive summary:

This report describes the corrosive properties of the Substance on a human threedimensional epidermal model (EpiDerm (EPI-200)). The possible corrosive potential of the Substance was tested through topical application for 3 minutes and 1 hour. The study procedures described in this report were based on the most recent OECD and EC guidelines.

The Substance was a very viscous amber liquid. Since the Substance was very viscous it was applied like a solid test substance. Approximately 25 mg of the Substance with 25 μl of Milli-Q water was applied directly on top of the skin tissue. The positive control had a mean relative tissue viability after 3 minutes exposure of 5%. The absolute mean OD540 (optical density at 540 nm) of the negative control tissues was within the laboratory historical control data range. The maximum inter tissue variability in viability between two tissues treated identically was less than 21% and the maximum difference in percentage between the mean viability of two tissues and one of the two tissues was less than 12%, indicating that the test system functioned properly. Skin corrosion is expressed as the remaining cell viability after exposure to the test substance.

The relative mean tissue viability obtained after 3 minutes and 1 hour treatment with the Substance compared to the negative control tissues was 108% at both exposure times. Since the mean relative tissue viability for the test substance was not below 50% after 3 minutes treatment and not below 15% after 1 hour treatment the Substance is considered to be not corrosive.

Finally, it is concluded that this test is valid and that the Substance is not corrosive in the in vitro skin corrosion test under the experimental conditions described in this report.