Didodecyl 1,4-dihydro-2,6-dimethylpyridine-3,5-dicarboxylate

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

29.06.2018 - 20.07.2018

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

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

28 July 2015

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.46 (In Vitro Skin Irritation: Reconstructed Human Epidermis Model Test)

Version / remarks:

Jul-2012

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Didodecyl 1,4-dihydro-2,6-dimethylpyridine-3,5-dicarboxylate

EC Number:

252-939-2

EC Name:

Didodecyl 1,4-dihydro-2,6-dimethylpyridine-3,5-dicarboxylate

Cas Number:

36265-41-5

Molecular formula:

C33H59NO4

IUPAC Name:

didodecyl 1,4-dihydro-2,6-dimethylpyridine-3,5-dicarboxylate

Test material form:

solid: particulate/powder

Results and discussion

In vitro

Results

Irritation / corrosion parameter:

% tissue viability

Value:

> 50

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

no indication of irritation

Any other information on results incl. tables

In the present study the skin irritant potential of Didodecyl 1,4-dihydro-2,6-dimethylpyridine-3,5-

dicarboxylate was analysed. The EpiDerm™-Standard Model (EPI-200™), a reconstituted threedimensional

human epidermis model, was used as a replacement for the Draize Skin Irritation Test

(OECD TG 404, [7]) to distinguish between UN GHS “Category 2” skin irritating test substances and

not categorized test substances (“No Category”) which may be considered as non-irritant. Hereby,

the test item was applied topically. Cytotoxicity is expressed as the reduction of mitochondrial

dehydrogenase activity measured by formazan production from MTT after a 60 min exposure and

42 h post-incubation period and compared to those of the concurrent negative controls.

The mixture of 25 mg test item per 1 mL MTT medium showed no reduction of MTT compared to the

solvent. The mixture did not turn blue/purple. Therefore, NSMTT equalled 0%.

The mixture of 25 mg of the test item per 300 μl aqua dest. showed no colouring detectable by

unaided eye-assessment. The mixture of 25 mg of the test item per 300 μl isopropanol showed

colouring detectable by unaided eye-assessment. Therefore, the absorption of the chemical in

isopropanol was measured in the range of 570 ± 30 nm. No absorption was measured in the

relevant range (see Figure 1). Therefore, NSC equalled 0%.

The test item showed no irritant effects. The mean relative tissue viability (% negative control) was

> 50% (109.8%) after 60 min treatment and 42 h post-incubation.

8.2. Conclusion

In this study under the given conditions the test item showed no irritant effects. The relative mean

tissue viability after 60 min of exposure and 42 h post-incubation was > 50%. The test item is

therefore classified as “non-irritant” in accordance with UN GHS “No Category”.