Fluocortolone

Skin irritation / corrosion

Administrative data

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

June 2016

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

Version / remarks:

2015

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

6-fluoro-11,21-dihydroxy-16- methylpregna-1,4-diene-3,20-dione

Cas Number:

152-97-6

Molecular formula:

C22H29FO4

IUPAC Name:

6-fluoro-11,21-dihydroxy-16- methylpregna-1,4-diene-3,20-dione

Test material form:

solid

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 method

Vehicle:

unchanged (no vehicle)

Details on test system:

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

TEMPERATURE USED FOR TEST SYSTEM
- Temperature used during treatment / exposure: RT (room temperature) for 3 min and incubator (37°C, CO2 5%) for 60 min
- Temperature of post-treatment incubation (if applicable): Incubator temperature: 37 ± 2° C (CO2 gas concentration: 5 %; Humidity: maximum)

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

PREDICTION MODEL / DECISION CRITERIA:
- Corrosivity potential of test materials is predicted from the cell viabilities obtained after 3 min and 60 min treatment compared to the negative control. A chemical is classified "corrosive" (sub-category 1A) if the cell viability after 3 min treatment is decreased by more than 50 %. If cell viability after 3 min exposure is ≥ 50 %, while it is below 15 % after 60 min exposure the substance is also classified as corrosive, but sub-category 1 B/1 C. If cell viability after 3 min exposure is ≥ 50 % and after 60 min exposure ≥ 15 %, the substance is classified as non-corrosive.

FUNCTIONAL MODEL CONDITIONS WITH REFERENCE TO HISTORICAL DATA
Reliability of the test was previously confirmed by interlaboratory validation

NUMBER OF REPLICATE TISSUES: triplicate


REMOVAL OF TEST MATERIAL AND CONTROLS
-Volume and number of washing steps: Volume and number not reported: After the exposure of the test item the inserts were washed carefully in PBS.
- Observable damage in the tissue due to washing: No

Control samples:

yes, concurrent negative control

Amount/concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 25 mg (plus 50 µl 0.9% NaCl to moisten and ensure good contact with the epidermis surface)

NEGATIVE CONTROL
- Amount(s) applied (volume or weight): 50 µl
- Concentration (if solution): 0.9% NaCl

Duration of treatment / exposure:

3 and 60 minutes

Number of replicates:

3

Results and discussion

In vitro

Results

Results 1

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

cell viability after 3 min [%]

Value:

95.94

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

not applicable

Results 2

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

cell viability after 60 min [%]

Value:

104.65

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

not applicable

Other effects / acceptance of results:

- OTHER EFFECTS:
- Visible damage on test system: not reported
- Direct-MTT reduction: not reported
- Colour interference with MTT: not reported

Any other information on results incl. tables

Table 1: Tabular summary of the results   

Sample No.	Test item	Time (min)	OD mean *	Std Dev	% Viability
1 - 3	Negative control NaCl 0.9 %	60	2.09	0.04	100.00
7 - 9	Fluocortolon	60	2.19	0.15	104.65
10 - 12	Negative control NaCl 0.9 %	3	2.28	0.06	100.00
16 - 18	Fluocortolon	3	2.18	0.14	95.94

* 6 values

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

A study for predicting a non-specific, corrosive potential of the test item by using reconstructed human epidermis (test method epiCS®) was performed according to OECD TG 431. For the determination of time related cytotoxic effects the incubation periods were 3 min. and 60 min. The MTT (Methylthiazoletetrazolium) viability test results (3 min.: 95.94 % viability; 60 min.: 104.65 % viability) showed, that fluocortolon has no corrosive property under the conditions of the assay used.

Executive summary:

In a dermal irritation study performed in accordance with OECD Guideline 431 (In Vitro Skin Corrosion, 2015), Fluocortolon (100% a.i.) was applied to the three-dimensional human epidermis model tissue for an exposure period of 3 and 60 minutes in triplicates. 50 μL of 0.9% NaCl were topically applied to the epidermal surface in order to improve further contact between the solid and the epidermis. Each approximately 25 mg of the test item were applied to the wetted tissues. The test item was spread to match the surface of the tissue.

 

After 3 minutes exposure at room temperature or 60 minutes exposure in the incubator, the tissues were washed with phosphate buffered saline to remove any residual test material. Cytotoxicity (irritancy) was expressed as the reduction of mitochondrial dehydrogenase activity measured by formazan production from MTT at the end of the treatment.

 

The negative (0.9% NaCl) control gave responses that were within the acceptance criteria and as such demonstrated the validity of the study.

 

The relative mean tissue viability obtained after 3 and 60 minutes treatment with Fluocortolon compared to the negative control tissues was 95.94 and 104.65%, respectively. Since the mean relative tissue viability for the test substance was above 50%, Fluocortolon is identified to be not corrosive.