Sodium 2-heptyl-2,3-dihydro-3-(2-hydroxyethyl)-1H-imidazole-1-propionate

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:

2017

Report date:

2017

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

“EpiDermTM In vitro Reconstructed Human Epidermis Skin Irritation Test (OECD 439 28 Jul 2015 and is based on the MatTek protocol (MK-24-007-0023, 11 July 14) using the MatTek Corporation EpiDermTM reconstructed tissue model EPI-200

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Sodium 2-heptyl-2,3-dihydro-3-(2-hydroxyethyl)-1H-imidazole-1-propionate

EC Number:

271-928-3

EC Name:

Sodium 2-heptyl-2,3-dihydro-3-(2-hydroxyethyl)-1H-imidazole-1-propionate

Cas Number:

68630-95-5

Molecular formula:

C15H28N2O3.Na

IUPAC Name:

sodium 3-[2-heptyl-3-(2-hydroxyethyl)-2,3-dihydro-1H-imidazol-1-yl]propanoate

Test material form:

solid

Details on test material:

Product name: Crodateric CYAP
Batch Number: PS-196-555
Appearance: The sample has been produced from drying of the aqueous solution of the material as sold commercially. It is observed to be a brown sticky solid

Specific details on test material used for the study:

Supplier Croda
Test Item name Crodateric CYAP-100
Supplier Code DEV080817DS3
Supplier batch/lot number PS-196-562
CAS number 70983-43-6
Purity 99.41% (from CofA)
Expiry Date 3 July 2018
Physical state Solid, Dark
Storage Conditions Room Temperature

In vitro test system

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Cell source:

other: cultured

Justification for test system used:

The reconstructed human epidermal model EpiDermTM (EPI-200-MatTek Corporation) 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 organised basal, spinous and granular layers and a multi-layered stratum corneum containing intercellular lamellar lipid layers arranged in patterns analogous to those found in vivo.
Initially the predictive capacity of the modified EpiDerm™ Skin Irritation Test (SIT) test method, using MatTek EpiDermTM tissue model EPI-200, underwent full prospective validation from 2003-2007. The test method components of this method were used to define the essential test methods components of the original and updated ECVAM Performance Standards (PS).

A modification of the original EpiDerm™ SIT was validated using the original ECVAM PS in 2008. In 2008, ESAC concluded that the Modified EpiDerm™ SIT has sufficient accuracy and reliability for prediction of R38 skin irritating and no-label (non-skin irritating) test substances

Vehicle:

unchanged (no vehicle)

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

After pre-wetting tissues with 25µl DPBS (Sterile Dulbecco’s Phosphate Buffered Saline), single topical application of nominal 25mg neat test item, 30µl of negative control (DPBS) or positive control (SDS 5%) to the surface of the EpiDermTM model for a set time.

Duration of treatment / exposure:

60 ± 1 minute* (25 minutes* at room temperature and 35 minutes at 37°C, 5% CO2, ≥95% Relative Humidity (RH)), followed by 42 ± 4h post-treatment incubation, prior to the MTT endpoint; three tissues per condition (n=3)

Duration of post-treatment incubation (if applicable):

42 ± 4h post-treatment incubation

Number of replicates:

3

Results and discussion

In vitro

Results

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

Percentage of viability (relative to negative control)

Value:

4.816

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Any other information on results incl. tables

Mean and SD of cell viability measurements and of viability percentages after 65 min of application and 42h (± 4h) post-incubation.

 

Name	Code	Mean of OD	SD of OD	Mean of viability (%)	SD of viability (%)	CV %	Classification
DPBS	NC	1.514	0.079	100.000	5.243	5.243	Non-Irritant
SDS 5%	PC	0.077	0.018	5.097	1.176	23.064	Irritant
Crodateric CYAP-100	TA1	0.082	0.017	5.427	1.096	20.191	Irritant

 

NC: Negative control (DPBS), PC: Positive control (SDS 5%), TA1: Crodateric CYAP-100.

 

Prediction model of irritancy: test items that reduce the viability to 50% or below are irritant (I), test items with a percentage viability above 50% are considered to be non-irritant (NI).

Applicant's summary and conclusion

Interpretation of results:

Category 2 (irritant) based on GHS criteria

Conclusions:

The skin irritation potential of Crodateric CYAP-100 was assessed in vitro according to OECD Test Guideline 439: In Vitro Skin Irritation: Reconstructed Human Epidermis Test Method.
After a 65 minute exposure on the surface of the EpiDermTM reconstructed human epidermis and a 42 ± 4h post-exposure incubation time, viability of the tissues was assessed and compared to the negative control. The percentage of viability obtained was 4.816 % and therefore since the test item reduced the viability to below 50% it should be considered as Irritant to the skin.