Dodecanoic acid, ester with 1,2,3-propanetriol, acetylated

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

14 Nov 2007

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP-Guideline study.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2007

Report date:

2007

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Deviations:

yes

Remarks:

no positive control used

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: EU Method B.40 bis (In Vitro Skin Corrosion: Human Skin Model Test)

Deviations:

yes

Remarks:

no positive control used

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Dodecanoic acid, ester with 1,2,3-propanetriol, acetylated

EC Number:

294-597-7

EC Name:

Dodecanoic acid, ester with 1,2,3-propanetriol, acetylated

Cas Number:

91744-35-3

IUPAC Name:

91744-35-3

Details on test material:

- Name of test material (as cited in study report): only trade name given
- Chemical name: Acetylided glyceride-mixture
- Physical state: light yellow liquid
- Analytical purity: 99.7%
- Composition of test material, percentage of components: triacetin, 0.2%; glycerol monolaurate, diacetylated, 73%; glycerol dilaurate, acetylated, 24%; glycerol trilaurate, 2.5%; unknown ingredients, 0.3%
- Lot/batch No.: CH70920C
- Expiration date of the lot/batch: 20 Sep 2008
- Storage condition of test material: at room temperature

Test animals

Species:

human

Strain:

other: reconstructed human epidermis EST-1000

Details on test animals or test system and environmental conditions:

TEST SKIN MODEL
- Source: CellSystems, St. Katharinen, Germany
- Adaptation to cell culture conditions: inserts with EST-1000 reconstructed human epidermis (0.6 cm²) were packed under sterile conditions and were shipped refrigerated on supplemented Agarose. Upon arrival, 6-well culture plates were pre-filled with 1 mL of fresh and cool maintenance medium. The reconstructed tissues were placed into the prepared cell culture plates (1 insert/well) and were adapted to the recommended tissue culture conditions (5% CO2, 37 °C, max humidity) afterwards for at least 6 h before use. In case of cultivation of the skin equivalents for more than 24 h, a daily medium change is required by aspirating the medium and replacing it by 1 mL new maintenance medium (37 °C) for each well.

ENVIRONMENTAL CONDITIONS (Incubator)
- Temperature (°C): 37 ± 2
- CO2 gas concentration (%): 5
- Humidity: maximum

Test system

Type of coverage:

open

Preparation of test site:

other: intact reconstructed human epidermis

Vehicle:

unchanged (no vehicle)

Controls:

other: concurrent negative control tissue treated with 0.9% NaCl

Amount / concentration applied:

TEST MATERIAL
- Amount applied: 0.05 mL (ca. 83 µL/cm²)

Duration of treatment / exposure:

3 min and 1 h

Observation period:

Not applicable

Number of animals:

Not applicable. Tests were performed in triplets for each treatment duration.

Details on study design:

TEST SITE
- Area of exposure: 0.6 cm²

REMOVAL OF TEST SUBSTANCE
- Washing (if done): after the incubation periods, the inserts were washed carefully with PBS.
- Time after start of exposure: 3 min and 1 h

CELL VIABILITY MEASUREMENTS
- Method: MTT assay
- Details on method used: for viability testing, the inserts were placed in new 24-well plates containing 300 µL of MTT solution (37 °C, 1 mg/mL in MTT-assay medium delivered by CellSystems®). The tissues were incubated for about 2 h under cell culture conditions (5% CO2, 37 °C, max humidity). The extraction of blue formazan was performed in isopropanol (24-well plates, 2 mL per insert) on a vertical shaker (at least 60 min). For determination of cell viability, the absorption of the isopropanol extracts was measured in duplicates at 570 nm in an automatic reader (EL808, Bio-Tek; 96-well format, 200 µL). Data acquisition and evaluation were done with "KC4" (software by Bio-Tek).
- Reliability check: Reliability of the test was confirmed before by interlaboratory validation.

Results and discussion

In vitro

Results

Results 1

Irritation / corrosion parameter:

other: other: cell viability (% of negative control)

Value:

100

Remarks on result:

other:

Remarks:

Basis: other: negative control (0.9% NaCl). Time point: 3 min. (migrated information)

Results 2

Irritation / corrosion parameter:

other: other: cell viability (% of negative control)

Value:

103.35

Remarks on result:

other:

Remarks:

Basis: other: test material. Time point: 3 min. (migrated information)

Results 3

Irritation / corrosion parameter:

other: other: cell viability (% of negative control)

Value:

100

Remarks on result:

other:

Remarks:

Basis: other: negative control (0.9% NaCl). Time point: 60 min. (migrated information)

Results 4

Irritation / corrosion parameter:

other: other: cell viability (% of negative control)

Value:

93.78

Remarks on result:

other:

Remarks:

Basis: other: test material. Time point: 60 min. (migrated information)

In vivo

Irritant / corrosive response data:

The cell viability after 3 min exposure was greater than 50% and the cell viability after 1 h exposure was greater than 15%.

Other effects:

No further effects were reported.

Any other information on results incl. tables

Table 1. Summary of results of the MTT assay.

 

Sample No.	Test item	Time (min)	OD mean (n = 6)	SD	% Viability
1-3	Control NaCl 0.9%	60	1.73	0.15	100.00
7-9	Test substance	60	1.62	0.05	93.78
10-12	Control NaCl 0.9%	3	1.81	0.10	100.00
16-18	Test substance	3	1.87	0.14	103.35

 

OD: Absorption at 570 nm

SD: Standard deviation

Applicant's summary and conclusion

Interpretation of results:

other: non-corrosive

Remarks:

Criteria used for interpretation of results: EU

Conclusions:

Under the conditions of this in vitro study, the test material is non-corrosive to reconstructed human epidermis. However, this study does not provide adequate information on skin irritation for classification purposes.
CLP: inconclusive
DSD: inconclusive