Aminocaproic acid

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

26 September 2016 - 21 November 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2016

Report date:

2016

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:

adopted July 28, 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:

Commission Regulation 440/2008, ATP 640/2012

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Aminocaproic acid

EC Number:

200-469-3

EC Name:

Aminocaproic acid

Cas Number:

60-32-2

Molecular formula:

C6H13NO2

IUPAC Name:

6-aminohexanoic acid

Test material form:

solid

In vitro test system

Test system:

human skin model

Source species:

other: reconstituted human epidermis

Cell type:

non-transformed keratinocytes

Justification for test system used:

The reconstructed human epidermis model in vitro method is an accepted in vitro method to replace animal testing. The human skin RHE™ model closely mimics the biochemical and physiological properties of the upper parts of the human skin, i.e. the epidermis, and has been validated by the ECVAM in 2008.

Vehicle:

unchanged (no vehicle)

Details on test system:

RECONSTRUCTED HUMAN EPIDERMIS (RHE) TISSUE
- Model used: SkinEthic™ RHE-model RHE/S/17
- Tissue batch number(s): 16-RHE-109
- Date of initiation of testing: On day of receipt the pre-incubation phase of the tissues started.

TEMPERATURE USED FOR TEST SYSTEM
- Temperature used during treatment / exposure: room temperature
- Temperature of post-treatment incubation: 37°C

REMOVAL OF TEST MATERIAL AND CONTROLS
- Volume and number of washing steps: rinsed with minimum 25 mL DPBS; excess DPBS removed by shaking the tissue inserts and blotting the bottom of the tissue inserts with blotting paper
- Observable damage in the tissue due to washing: no data
- Modifications to validated SOP: none

MTT DYE USED TO MEASURE TISSUE VIABILITY AFTER TREATMENT / EXPOSURE
- MTT concentration: 1 mg/mL
- Incubation time: 3 hours
- Spectrophotometer: microplate reader ELx800, BioTek Instruments GmbH
- Wavelength: 570 nm

NUMBER OF REPLICATE TISSUES: 3

NUMBER OF INDEPENDENT TEST SEQUENCES / EXPERIMENTS TO DERIVE FINAL PREDICTION: 1

PREDICTION MODEL / DECISION CRITERIA
- The test substance is considered to be irritant to skin category 2 if the viability is less than or equal to 50%.
- The test substance is considered to be non-irritant to skin if the viability is greater than 50%.

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

TEST MATERIAL
- Amount applied: 16 mg

Duration of treatment / exposure:

42 minutes

Duration of post-treatment incubation (if applicable):

42 hours

Number of replicates:

3 triplicate tissues (3 aliquots per tissue)

Results and discussion

In vitro

Results

Results 1

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

Tissue 1

Value:

91.62

Vehicle controls validity:

not examined

Negative controls validity:

valid

Positive controls validity:

valid

Results 2

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

Tissue 2

Value:

87.19

Vehicle controls validity:

not examined

Negative controls validity:

valid

Positive controls validity:

valid

Results 3

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

Tissue 3

Value:

81.7

Vehicle controls validity:

not examined

Negative controls validity:

valid

Positive controls validity:

valid

Other effects / acceptance of results:

OTHER EFFECTS
- Direct-MTT reduction: no
- Colour interference with MTT: no

ACCEPTANCE OF RESULTS:
- Acceptance criteria met for negative control: Yes
- Acceptance criteria met for positive control: Yes
- Acceptance criteria met for variability between replicate measurements: Yes

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Under the conditions of the present study, the test item is not considered to possess an irritant potential to skin (UN GHS: No Category).

Executive summary:

An in vitro study in accordance with the OECD Guideline OECD 439 was performed to assess the skin irritation potential of the test item.

Triplicates of the human skin RHE-model were treated with the test item, the negative or the positive control for 42 minutes. 16 µL of either the negative control (DPBS) or the positive control (5% SLS) were applied to the tissues. Before application of 16 mg of the solid test item, 10 µL of deionised water was spread to the epidermis surface to improve the contact between the test item and the epidermis.

The test item did not reduce MTT, and it did not indicate colour interference. All of the acceptability criteria were met. The absorbance values of the negative control were between 1.7 and 1.9. The positive control induced a sufficient decrease of the relative absorbance as compared to the negative control. The relative standard deviations of three replicates were below 18%.

As a result, the mean relative absorbance was determined to be 86.8% compared to the relative absorbance of the negative control after treatment with the test item. Therefore, the test item is not considered to possess an irritant potential to skin under the experimental conditions chosen (UN GHS: No Category).