Valeric anhydride

Skin irritation / corrosion

Administrative data

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

October 2015

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

Qualifier:

according to guideline

Guideline:

OECD Guideline 431 (In Vitro Skin Corrosion: Human Skin Model Test)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Valeric anhydride

EC Number:

218-212-9

EC Name:

Valeric anhydride

Cas Number:

2082-59-9

Molecular formula:

C10H18O3

IUPAC Name:

pentanoyl pentanoate

Constituent 2

Reference substance name:

Pentanoic acid, 1,1¿-anhydride

IUPAC Name:

Pentanoic acid, 1,1¿-anhydride

Constituent 3

Reference substance name:

Valeriansäureanhydrid

IUPAC Name:

Valeriansäureanhydrid

Test material form:

other: liquid

Details on test material:

- Purity: Not specified

In vitro test system

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Justification for test system used:

commercially available test system

Vehicle:

unchanged (no vehicle)

Details on test system:

RECONSTRUCTED HUMAN EPIDERMIS (RHE) TISSUE
- Model used: epiCS® (CellSystems, Troisdorf, Germany).
- Tissue batch number(s): Cat.-No.CS-1001

TEMPERATURE USED FOR TEST SYSTEM
- Temperature used during treatment / exposure: room temperature for 3 min- exposure and incubator (37
± 2° C) for 60 min- exposure

MTT DYE USED TO MEASURE TISSUE VIABILITY AFTER TREATMENT / EXPOSURE
- MTT concentration: 1mg/ml
- Incubation time: 3 hours
- Spectrophotometer: EL808, Bio-Tek
- Wavelength: 570 nm

NUMBER OF INDEPENDENT TESTING RUNS / EXPERIMENTS TO DERIVE FINAL PREDICTION:
the optical density of the isopropanol-extracts of 3 inserts was determined by duplicate per insert = 6 OD
values.

PREDICTION MODEL / DECISION CRITERIA:
- The mean optical density (OD) value obtained with the test item was used to calculate the percentage of
viability relative to the negative control, which is set at 100 %.
- classification according to UN GHS: if the mean percent tissue viability after 3 min-exposure is less than
(<) 50 % the test item is classified as corrosive (Category 1A); if the mean percent tissue viability after 3-
min-exposure is greater than or equal (≥) to 50 % AND < 15% after 60-min exposure the test item is class
ified as corrosive (Category 1B/1C); if the mean percent tissue viability after 60-min-exposure is ≥ 50 % af
ter 3-min exposure AND ≥ 15% after 60-min exposure the test item is considered as non-corrosive

The corrosive potential of the test item is assessed by determination of its cytotoxic effect on an in vitro
reconstructed human epidermis. The test principle is based on the MTT assay reflecting the cell viability
after exposure to the topically applied test item.
All tests were performed in triplets for each time point. The test item was applied at a 100% concentration,
i.e. 50 μl per insert for 3 min. (room temperature) and 60 min. Cell viability was measured by the amount
of MTT reduction (calculated on the basis of optical density of the negative control).

Control samples:

yes, concurrent negative control

Amount/concentration applied:

TEST MATERIAL
- Amount(s) applied: 50 µl
- Concentration (if solution): undiluted


NEGATIVE CONTROL
- Amount(s) applied: 50 µl
- Concentration (if solution): 0.9% NaCl in water

Duration of treatment / exposure:

3 min and 60 min

Number of replicates:

three

Results and discussion

In vitro

Results

Results 1

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

exposure period: 3 min

Value:

ca. 92

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

not specified

Results 2

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

exposure period: 60 min.

Value:

ca. 60

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

not specified

Other effects / acceptance of results:

DEMONSTRATION OF TECHNICAL PROFICIENCY:
- Reliability of the test was previously confirmed by interlaboratory validation

ACCEPTANCE OF RESULTS:
- Acceptance criteria met for negative control: yes
- Acceptance criteria met for positive control: yes, within regular intervals in the lab
- Acceptance criteria met for variability between replicate measurements: yes

Any other information on results incl. tables

Table 1: Tabular Summary of the results

Sample No.	Test item	Exposure time [min]	OD mean*	StdDev	% Viability
1 -3	Control NaCl 0.9%	60	2.72	0.15	100.00
4 -6	Valeriansäureanhydrid	60	1.63	0.32	59.75
10 -12	Control NaCl 0.9%	3	2.75	0.06	100.00
13 -15	Valeriensäureanhydrid	3	2.52	0.07	91.70

 *6 values

Applicant's summary and conclusion

Interpretation of results:

other: negative

Executive summary:

A study was performed for the assessment of the skin corrosion of the test item with reconstructed human epidermis (RhE). The experiment was carried out using the commercially available test method epiCS®. The study was conducted in accordance with OECD TG 431 and EU Test Method B.40 bis. The mean value of cell viability was recorded to be 92 % (3 min. exposure) and 60 % (60 min. exposure). The test item was thus shown to be not corrosive to reconstructed human skin in vitro.