Ethanol, 2,2'-oxybis-, reaction products with 3-(triethoxysilyl)-1-propanamine

Skin irritation / corrosion

Administrative data

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2018-01-16 to 2018-01-18

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 431 (In Vitro Skin Corrosion: Reconstructed Human Epidermis (RHE) Test Method)

Version / remarks:

29 July 2016

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: Council Regulation 440/2008, Method B.40 BIS: “In Vitro Skin Corrosion: Human Skin Model Test”, May 30, 2008

Test guideline 3

Qualifier:

according to guideline

Guideline:

other: MatTek Corporation Protocol for: In Vitro EpiDermTM Skin Corrosion Test (EPI-200-SCT) For use with MatTek Corporation’s Reconstructed Human Epidermal Model EpiDerm; Version 07/11/2014

GLP compliance:

yes (incl. QA statement)

Remarks:

(Bayerisches Landesamt für Gesundheit und Lebensmittelsicherheit, München, Germany)

Test material

Test material information

Constituent 1

Reference substance name:

Ethanol, 2,​2'-​[1,​2-​ethanediylbis(oxy)​]​bis-​, reaction products with 3-​(triethoxysilyl)​-​1-​propanamine

EC Number:

813-152-5

Cas Number:

152261-44-4

Molecular formula:

Unspecified

IUPAC Name:

Ethanol, 2,​2'-​[1,​2-​ethanediylbis(oxy)​]​bis-​, reaction products with 3-​(triethoxysilyl)​-​1-​propanamine

Test material form:

liquid

In vitro test system

Test system:

human skin model

Remarks:

EpiDerm

Source species:

human

Cell type:

non-transformed keratinocytes

Justification for test system used:

This test uses the EpiDerm™ reconstructed human epidermis model (MatTek) which consists of normal human epidermal keratinocytes (NHEK) and therefore represents in vitro the target organ of the species of interest and closely mimics the biochemical and physiological properties of the upper parts of the human skin, i.e. the epidermis.

Vehicle:

unchanged (no vehicle)

Details on test system:

The test was carried out with the reconstituted three-dimensional human skin model EpiDerm (MatTek). This skin model consists of normal (non-cancerous), human-derived epidermal keratinocytes (NHEK) which have been cultured to form a multilayered, highly differentiated model of the human epidermis. The NHEK are cultured on chemically modified, collagen-coated cell culture inserts (Millicell). The EpiDerm skin model exhibits in vivo-like morphological and growth characteristics which are uniform and highly reproducible. It consists of organised basal, spinous, granular and cornified layers analogous to those found in vivo.

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

50 µL

Duration of treatment / exposure:

3 minutes and 60 minutes

Duration of post-treatment incubation (if applicable):

3 h MTT incubation

Number of replicates:

2

Results and discussion

In vitro

Results

Results 1

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

60 min. treatment

Value:

97.5

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Remarks:

100.0

Positive controls validity:

valid

Remarks:

1.5

Results 2

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

3 min. treatment

Value:

106.8

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Remarks:

100.0

Positive controls validity:

valid

Remarks:

5.2

Other effects / acceptance of results:

Value Cut off pass/fail
Mean Absolute OD570 nm NK
(3 min Experiment) 1.609 0.8 ≤ NK ≤ 2.8 pass
Mean Absolute OD570 nm NK
(60 min Experiment) 1.670 0.8 ≤ NK ≤ 2.8 pass
Mean Relative Tissue Viability [%] of
PC (60 min experiment) 1.5 < 15% pass
CV [%]
(in the range of 20 – 100% viability) 7.8% - 20.1% ≤ 30% pass

Any other information on results incl. tables

The test item showed non-specific MTT-reducing potential. Therefore, additional killed tissue controls were treated with the test item to determine the non-specific reduction of MTT (NSMTT) and the results were corrected to the true MTT metabolic conversion (TODTT). The test item showed no water-colouring potential.

The test item showed no corrosive effects. The mean relative tissue viability (% negative control) was ≥ 50% (110.7%, NSMTT-corrected) after 3 min treatment and ≥ 15% (97.6%, NSMTTcorrected) after 60 min treatment.

The controls confirmed the validity of the study. The mean OD570nm of the two negative control tissues was ≥ 0.8 and ≤ 2.8 for each exposure period. The mean relative tissue viability (% negative control) of the positive control was < 15% (1.5%) after 60 min treatment. The coefficient of variation (CV) (in the range of 20 – 100% viability) of replicate tissues of all dose groups was ≤ 30% (7.8% - 20.1%).

Results of 3 minExperiment

Name	Negative Control		Test Item		Positive Control
Tissue	1	2	1	2	1	2
Absolute OD570	1.818	1.381	1.687	1.694	0.130	0.122
	1.854	1.399	1.702	1.704	0.129	0.125
	1.823	1.380	1.712	1.789	0.129	0.125
OD570- Blank Corrected	1.773	1.335	1.642	1.648	0.085	0.077
	1.808	1.354	1.656	1.659	0.083	0.079
	1.777	1.334	1.666	1.744	0.084	0.079
Mean OD570of 3 Aliquots (Blank Corrected)	1.786	1.341	1.655	1.684	0.084	0.079
SD OD570 of 3 Aliquots	0.019	0.011	0.012	0.052	0.001	0.001
Total Mean OD570of 2 Replicate Tissues (Blank Corrected)	1.564*		1.669		0.081
TODTT	-		1.731		-
SD OD570 of 2 Replicate Tissues	0.315		0.021		0.004
Mean Relative Tissue Viability [%]	100.0		106.8		5.2
Mean Relative Tissue Viability [%] - NSMTT Corrected	-		110.7		-
Coefficient Of Variation [%]^***	20.1		1.2		4.8

^*     corrected mean OD₅₇₀ of the negative control corresponds to 100% absolute tissue viability.

^***   coefficient of variation (CV) (in the range of 20 – 100% viability) between two tissues treated identically is ≤ 30%.

Results of the NSMTT control of 3 min Experiment

NSMTT	KU		KT		Negative Control
Tissue	1	2	1	2	1	2
absolute OD570 -values	0.576	0.495	0.449	0.501	1.818	1.381
	0.590	0.490	0.460	0.497	1.854	1.399
	0.597	0.493	0.445	0.497	1.823	1.380
OD570(Blank Corrected)	0.531	0.450	0.404	0.455	1.773	1.335
	0.545	0.445	0.415	0.451	1.808	1.354
	0.552	0.448	0.399	0.452	1.777	1.334
mean OD570 (mean of 2 aliquots)	0.538	0.448	0.409	0.453	1.791	1.344
total mean OD570 (mean of the replicate tissues)	0.493		0.431		1.568*
SD OD570(of the replicate tissues)	0.064		0.031		0.315
NSMTT [%]	-3.92				-
Relative Tissue Viability [%]	-				114.2	85.8
Mean Relative Tissue Viability [%]	-				100.0
SD Tissue Viability [%]	-				20.1
CV [% Viabilities]	-				20.1

Results of 60 min Experiment

Name	Negative Control		Test Item		Positive Control
Tissue	1	2	1	2	1	2
Absolute OD570	1.576	1.710	1.415	1.817	0.070	0.069
	1.579	1.783	1.419	1.816	0.072	0.069
	1.587	1.787	1.494	1.822	0.072	0.069
OD570- Blank Corrected	1.531	1.665	1.370	1.771	0.025	0.024
	1.533	1.738	1.374	1.771	0.027	0.024
	1.542	1.742	1.449	1.776	0.027	0.024
Mean OD570of 3 Aliquots (Blank Corrected)	1.535	1.715	1.397	1.773	0.026	0.024
SD OD570 of 3 Aliquots	0.006	0.043	0.044	0.003	0.001	0.000
Total Mean OD570of 2 Replicate Tissues (Blank Corrected)	1.625*		1.585		0.025
TODTT	-		1.586		-
SD OD570 of 2 Replicate Tissues	0.127		0.266		0.002
Mean Relative Tissue Viability [%]	100.0		97.5		1.5**
Mean Relative Tissue Viability [%] - NSMTT Corrected	-		97.6		-
Coefficient Of Variation [%]^***	7.8		16.8		6.3

^*           corrected mean OD₅₇₀ of the negative control corresponds to 100% absolute tissue viability.

^**             mean relative tissue viability of the 60 min positive control < 15%.

^***            coefficient of variation (CV) (in the range of 20 – 100% viability) between two tissues treated identically is ≤ 30%.

Results of the NSMTT control of 60 min Experiment

NSMTT	KU		KT		Negative Control
Tissue	1	2	1	2	1	2
absolute OD570 -values	0.106	0.095	0.087	0.113	1.576	1.710
	0.107	0.095	0.088	0.112	1.579	1.783
	0.106	0.094	0.087	0.112	1.587	1.787
OD570(Blank Corrected)	0.061	0.049	0.041	0.068	1.531	1.665
	0.062	0.049	0.043	0.067	1.533	1.738
	0.061	0.049	0.042	0.066	1.542	1.742
mean OD570 (mean of the aliquots)	0.061	0.049	0.042	0.067	1.532	1.702
total mean OD570 (mean of the replicate tissues)	0.055		0.055		1.617*
SD OD570(of the replicate tissues)	0.008		0.018		0.120
NSMTT [%]	-0.04				-
Relative Tissue Viability [%]	-				97.7	108.6
Mean Relative Tissue Viability [%]	-				103.1
SD Tissue Viability [%]	-				7.6
CV [% Viabilities]	-				7.4

 

Applicant's summary and conclusion

Interpretation of results:

other: not corrosive

Conclusions:

In this study under the given conditions the test item showed no corrosive effects. The test item is classified as “non-corrosive“.

Executive summary:

In the present study the skin corrosivity potential of the test item was analysed. Since corrosive chemicals are cytotoxic after a short time exposure to the stratum corneum of the epidermis the cytotoxic effects of the test item on EpiDerm, a reconstituted three-dimensional human epidermis model, were determined. 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 3 min and 60 min exposure period and compared to those of the concurrent negative controls.

The test item showed non-specific MTT-reducing potential. Therefore, additional killed tissue controls were treated with the test item to determine the non-specific reduction of MTT (NSMTT) and the results were corrected to the true MTT metabolic conversion (TOD_TT). The test item showed no water-colouring potential.

The test item showed no corrosive effects. The mean relative tissue viability (% negative control) was ≥ 50% (110.7%, NSMTT-corrected) after 3 min treatment and ≥ 15% (97.6%, NSMTT-corrected) after 60 min treatment.