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Toxicological information

Skin irritation / corrosion

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Administrative data

Endpoint:
skin irritation: in vitro / ex vivo
Remarks:
in vitro
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:
OECD Guideline 439 (In Vitro Skin Irritation: Reconstructed Human Epidermis Test Method)
Version / remarks:
Adopted on 28 July 2015
Deviations:
no
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
liquid
Details on test material:
Legal entity composition

In vitro test system

Test system:
human skin model
Source species:
other: Reconstructed Human Epidermis TestMethod: EPISKIN™
Cell type:
other: epidermis keratinocytes as cell source and use of representative tissue and cytoarchitecture
Cell source:
other: Reconstructed Human Epidermis TestMethod: EPISKIN™ - Batch 18-EKIN-002
Source strain:
not specified
Vehicle:
unchanged (no vehicle)
Details on test system:
In the Main Assay, alive tissues were treated with the test item (20 microliters), positive and negative controls.
D-BPS was used as negative control and 5% (w/v) of sodium dodecyl sulphate (SDS) solution was instead used as positive control.
Control samples:
yes, concurrent negative control
yes, concurrent positive control
Amount/concentration applied:
20 microliters of test item; 20 microliters of the solution as positive control; 20 microliters of D-PBS.
Duration of treatment / exposure:
15 +/- 0.5 minutes in a ventilated cabinet at room temperature
Duration of post-treatment incubation (if applicable):
A 42 ± 1 hour recovery period was allowed by incubation at 37°C, 5% CO2 and saturated humidity.
Number of replicates:
3 replicated for each tested item

Results and discussion

In vitro

Resultsopen allclose all
Irritation / corrosion parameter:
other: Colour observation
Run / experiment:
Preliminary test - Direct MTT reduction test
Value:
0
Vehicle controls validity:
not applicable
Negative controls validity:
valid
Positive controls validity:
valid
Remarks on result:
other: Colourless drops, no colour change (no interaction)
Irritation / corrosion parameter:
other: Colour observation
Run / experiment:
Colouring potential test
Value:
0
Vehicle controls validity:
not applicable
Negative controls validity:
valid
Positive controls validity:
valid
Remarks on result:
other: Colourless solution (no interaction)
Irritation / corrosion parameter:
other: Optical Density
Run / experiment:
Main assay
Value:
0.718
Vehicle controls validity:
not applicable
Negative controls validity:
valid
Positive controls validity:
valid
Remarks on result:
no indication of irritation
Remarks:
The test item did not induce cell death in any replicate, the mean cell viability after the blank subtraction was 110% when compared to the negative control
Other effects / acceptance of results:
The negative control gave the expected baseline value (Optical Density values of the three replicates higher than 0.6) and variability [Standard Deviation (SD) of % viability lower or equal to 18], in agreement with the guideline indications. According to the method, the
negative control mean value is considered the baseline value of the experiment and thus represents 100% of cell viability. The positive control caused the expected cell death (2% of cell viability when compared to the negative control) and variability (SD of % viability equal to 0.5). Based on the stated criteria
(mean viability ≤ 40% and SD of % viability ≤ 18), the assay was regarded as valid. The test item did not induce cell death in any replicate, the mean cell viability after the blank subtraction was 110% when compared to the negative control. Intra-replicate variability was acceptable with a SD of % viability value equal to 16.6 (lower than 18, as stated in the Study Protocol).

Any other information on results incl. tables

MAIN ASSAY

BLANK              Negative Control

 

OD

 

 

OD

OD-blank                                             Viability(%)

0.0043

N1 -1

 

0.742

0.7023                           0.6988             109.1

0.041

N1 -2

 

0.735

0.6453

0.035

N2 -1

 

0.685

0.6453                        0.6453              102 .1

0.041

N2 -2

 

0.703

0.6633

0.038

N3 -1

 

0.609

0.5693                         0.5693                 88.8

0.040

N3 -2

 

0.609

0.5693

Mean

0.040

Mean

0.681

Mean

0.6

100

SD

0.003

SD

0.1

SD

0.07

10.3

CV(%)

7.1

CV(%)

8.7

CV(%)

10.3

10.3

 

Positive Control

 

 

OD

 

 

OD-blank

 

 

Viability(%)

 

0.0108                         1.7  

 

  0.0083 1.3

                        

  0.0143 2.2

 

P1-1

0.052

0.0123

P1-2

0.049

0.0093

P2-1

0.044

0.0043

P2-2

0.052

0.0123

P3-1

0.053

0.0133

P3-2

0.055

0.0153

Mean

0.051

 

Mean

0.011

2

SD

0.004

 

SD

0.003

0.2

CV(%)

7.6

 

CV(%)

27.0

27.0

 

Test Item

 

 

OD

 

 

OD-blank

 

 

Viability(%)

 

0.6363                          99.3

 

 

0.7918                        123.6

 

 

0.6078                        94.9

B1-1

0.671

0.6313

B1-2

0.681

0.6413

B2-1

0.824

0.7843

B2-2

0.839

0.7993

B3-1

0.641

0.6013

B3-2

0.654

0.6143

Mean

0.718

 

Mean

0.7

106

SD

0.09

 

SD

0.10

15.5

CV(%)

12.4

 

CV(%)

14.6

14.6

DISCUSSION

The mean Optical Density of Blank Controls was 0.040, lower than the maximum acceptable value (0.1). The negative control gave the expected baseline value (Optical Density values of the three replicates higher than 0.6) and variability (Standard Deviation of the % viability lower or equal to 18), in agreement with guideline indications. According to the method, the mean value is considered the baseline value of the experiment and thus represents 100% of cell viability.

Positive control results indicated an appropriate cell death with an acceptable relative cell viability (2% of the negative control value). Variability between replicates gave also the expected value (SD of%viability = 0.5). Based on the stated criteria, mean viability, expressed as percentage of the negative control, lower or equal to 40% and standard deviation of % viability equal or lower than 18, the study was accepted as valid.

The test item did not induce cell death in any replicate, the mean cell viability after the blank subtraction was 106% when compared to the negative control. Intra-replicate variability was acceptable with a SD of % viability value equal to 15.5 (lower than 18, as stated in the Study Protocol).

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
Conclusions:
Neopentyl Glycol Dopelargonate is considered as "not corrosive in the human Skin Model Test"
Executive summary:

The study was followed in according to OECD guideline and GLP without significate deviations.

The potential of the test item Neopentyl Glycol Dipelargonate to be irritant to the skin was investigated through an in vitro skin irritation study, using a commercial reconstructed human epidermis (RhE) model named EPISKIN™.

The blank, negative and positive controls gave acceptable results and the study was accepted as valid.

The mean cell viability of the test item treated tissues, after the blank subtraction, was 106%. Based on the results obtained, the test item Neopentyl Glycol Dipelargonate is classified as non-irritant to the skin (UN GHS No Category).