Docosyl methacrylate

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Report date:

2018

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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:

Docosyl methacrylate

EC Number:

240-714-1

EC Name:

Docosyl methacrylate

Cas Number:

16669-27-5

Molecular formula:

C26H50O2

IUPAC Name:

docosyl methacrylate

Test material form:

solid

In vitro test system

Test system:

human skin model

Vehicle:

unchanged (no vehicle)

Details on test system:

The EpiDerm TM model consists of normal, human-derived epidermal keratinocytes which have been cultured to form a multi layered, highly differentiated model of the human epidermis. It consists of organized basal, spinous and granular layers, and a multilayered stratum corneum containing intercellular lamellar lipid layers arranged in patterns analogous to those found in viva. The EpiDerm TM tissues (surface 0.6 cm2)
are cultured on specially prepared cell culture inserts (MILLICELLs®, 10 mm ø) and commercially available as kits (EpiDerm TM 200), containing 24 tissues on shipping agarose.
Skin model: Epi-200
Supplier: MatTek In Vitro Life Science Laboratories, Bratislava, Slovakia

On the day of arrival in the laboratory, the tissues will be transferred to sterile 6-well plates with 0.9 ml assay medium and preconditioned in the incubator at 37°C. After
1 hour, the pre-incubation medium is replaced with fresh medium and preconditioning
continues for 18 ± 3 hours.

Three tissues are treated with each test substance, the PC and the NC, respectively. Three additional tissues (KC) will be used for the test substance and the NC, respectively, if a positive reaction has been observed in the MTT reduction test. 25 μL sterile PBS are applied first. Due to the physical state of the test substance, application with a pipette or sharp spoon is not possible. Thus, a metal pin is covered with 50 μL undiluted liquid (at ca. 50°C heated) test substance. The pin is applied with direct
contact to the tissue, covering the whole tissue surface. Before application, the test
substance is cooled down to room temperature.
Control tissues are treated concurrently with 30 μL sterile PBS (NC, NC KC (if applicable)) or 5% SOS (PC) ortest substance (KC, if applicable). After application, a
nylon mesh is placed carefully onto each tissue surface of the NC and the PC and if
applicable, onto each tissue surface of the NC KC and the test substance KC.
The tissues are kept under the laminar flow hood at room temperature for 25 minutes and in the incubator for 35 minutes. The tissues are washed with sterile PBS to remove residual test material 1 hour after start of application. Rinsed tissues are blotted on sterile absorbent paper and transferred into new 6-well plates pre-filled with 0.9 ml fresh medium. When all tissues are rinsed, the surface of each tissue is dried carefully with a sterile cotton swab. Subsequently, the tissues are incubated in the incubator at 37°C for 24 ± 2 hours.
After 24 ± 2 hours, the tissues are transferred into new 6-well plates pre-filled with 0.9 ml
fresh medium and placed into the incubator for an additional 18 ± 2-hour post-incubation
period. After the post-incubation period, the assay medium is replaced with 0.3 ml MTT solution and the tissues are incubated in the incubator for 3 hours. After incubation, the tissues are washed with PBS to stop the MTT incubation. The formazan that is produced metabolically by the tissues will be extracted by incubation of the tissues in 2 ml isopropanol at room temperature on a plate shaker (ca. 120 rpm) for at least 2 hours. After shaking the isopropanol extract, 2 aliquots of each extract per tissue will be transferred to a 96-well microtiter plate. The optical density (OD570) will be determined spectrophotometrically using a filter with a wavelength of 570 nm.

Results and discussion

In vitro

Results

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

mean

Value:

98.8

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Based on the observed results and applying the evaluation criteria it was concluded, that Docosyl methacrylate does not show a skin irritation potential in the EpiDerm in vitro skin irritation test under the conditions chosen.