(R)-2-(2,5-difluorophenyl)pyrrolidine (R)-2-hydroxysuccinate

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Sept-Nov 2021

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2021

Report date:

2021

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:

2021

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.46 (In Vitro Skin Irritation: Reconstructed Human Epidermis Model Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Specific details on test material used for the study:

-Purity (HPLC area %) 100
-Test item was used undiluted.
-For the solid test item 30 µl of 0.9% NaCl were used to moisten and ensure good contact with the epide1mis surface.

In vitro test system

Test system:

human skin model

Source species:

human

Justification for test system used:

commercially available test method

Vehicle:

other: 0.9% NaCl

Details on test system:

RECONSTRUCTED HUMAN EPIDERMIS (RHE) TISSUE
- Model used: epiCS® (Henkel AG & Co, KGaA, Düsseldorf))

TEMPERATURE USED FOR TEST SYSTEM
- Temperature used during treatment / exposure: RT (room temperature)
- 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

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

PREDICTION MODEL / DECISION CRITERIA
- The mean optical density (OD) values obtained with the test item were used to calculate the
percentage of viability relative to the negative control, which is set at 100 %.
- According to UN GHS (Category 2 or Category 1) if the mean percent tissue viability after exposure and post treatment incubation is less than or equal (≤ ) to 50 %.

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 30 mg (plus 30 µl 0.9% NaCl to moisten and ensure good contact with the epidermis surface)

NEGATIVE CONTROL
- Amount(s) applied (volume or weight): 30 µl
- Concentration (if solution): 0.9% NaCl in water

POSITIVE CONTROL
- Amount(s) applied (volume or weight): 30 µl
- Concentration (if solution): 5% SDS in physiological saline

Duration of treatment / exposure:

20 minutes

Duration of post-treatment incubation (if applicable):

42 hours

Number of replicates:

3

Results and discussion

In vitro

Results

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

cell viability, after 20 min [%]

Value:

100.58

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

no indication of irritation

Other effects / acceptance of results:

- OTHER EFFECTS:
- Visible damage on test system: No
- Direct-MTT reduction: No - according to the results of the pre-check
- Colour interference with MTT: No - according to the results of the pre-check

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
- 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	OD mean *	Std Dev	% Viability
1 - 3	Negative control NaCl 0.9 %	1.83	0.02	100.00
4 - 6	Positive control SDS 5 %	0.02	0.00	1.31
7 -9	test item (DFPP MALAT)	1.84	0.01	100.58

 

* 6 values

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

not irritant, no classification warranted

Executive summary:

A study was performed for the assessment of the skin irritancy of the test item DFPP MALAT with reconstructed human epidermis (RhE). The experiment was carried out in vitro using the commercially available test method epiCS®.
The study was conducted in accordance with OECD TG 439 and EU Test Method B.46.
The test item was applied undiluted topically to the RhE tissue construct in triplicates and incubated for 20 minutes, followed by a 42 hours post-treatment incubation period.
Cell viability was measured in a photometer by the amount of MTT (methylthiazole tetrazolium) reduction. The optical density value obtained for the test item was used to calculate the percentage of viability relative to the negative control, which is set at 100%.
The results of the concurrent negative control (NC, 0.9 % NaCl) and positive control (PC, 5 % SDS) demonstrated the viability (NC) and sensitivity (PC) of the test model.
The following value of cell viability was recorded for the test item: 101 % (rounded).
In conclusion the results of the assay used show no skin initant properties of the test item DFPP MALAT and thus, the test item requires no classification according to CLP.