4-chloro-7H-pyrrolo[2,3-d]pyrimidine

Skin irritation / corrosion

Administrative data

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2019

Report date:

2019

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 431 (In Vitro Skin Corrosion: Reconstructed Human Epidermis (RHE) Test Method)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

4-chloro-7H-pyrrolo[2,3-d]pyrimidine

EC Number:

628-079-2

Cas Number:

3680-69-1

Molecular formula:

C6H4ClN3

IUPAC Name:

4-chloro-7H-pyrrolo[2,3-d]pyrimidine

Test material form:

solid

Details on test material:

Batch (Lot) Number: GR13290
Expiry date: 31 January 2020 (expiry date)
Physical Description: White to off-white solid
Purity/Composition: 99.1%
Storage Conditions: At room temperature

In vitro test system

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Cell source:

other: not specified

Justification for test system used:

Recommended test system in international guidelines (OECD and EC).

Vehicle:

unchanged (no vehicle)

Details on test system:

EpiDerm Skin Model (EPI-200, Lot no.: 29642, kit J and K).
The model consists of normal, human-derived epidermal keratinocytes which have been
cultured to form a multilayered, highly differentiated model of the human epidermis.
It consists of organized 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. The EpiDerm tissues (surface 0.6 cm2) were cultured on polycarbonate
membranes of 10 mm cell culture inserts.

Source
MatTek Corporation, Ashland MA, U.S.A.

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

26.8 to 31.3 mg of the solid test item was added into the 6-well plates on top of the skin tissues.

Duration of treatment / exposure:

3 minutes and 1 hour

Number of replicates:

duplicate

Results and discussion

In vitro

Results

Results 1

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

3 minute

Value:

106

Negative controls validity:

valid

Positive controls validity:

valid

Results 2

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

1 hour

Value:

96

Negative controls validity:

valid

Positive controls validity:

valid

Other effects / acceptance of results:

ACCEPTABILITY CRITERIA
The in vitro skin corrosion test is considered acceptable if it meets the following criteria:
a) The absolute mean OD570 of the two tissues of the negative control should reasonably be
within the laboratory historical control data range.
b) The mean relative tissue viability following 1-hour exposure to the positive control
should be <15 %.
c) In the range 20 - 100% viability, the Coefficient of Variation (CV) between tissue
replicates should be <= 30%.

Any other information on results incl. tables

PF-01323624 was checked for color interference in aqueous conditions and possible direct

MTT reduction by adding the test item to MTT medium. Because the solutions did not turn

blue / purple nor a blue / purple precipitate was observed it was concluded that the test item

did not interfere with the MTT endpoint.

The mean absorption at 570  nm  measured after treatment with  PF-01323624 and controls are

presented in Appendix 1, Table 1. The individual OD570 measurements are presented in

Appendix 2.

Table 2 shows the mean tissue viability obtained after 3-minute and 1-hour treatments with

PF-01323624 compared to the negative control tissues. Skin corrosion is expressed as the

remaining cell viability after exposure to the test item. The relative mean tissue viability

obtained after the 3-minute and 1-hour treatments with  PF-01323624 compared to the

negative control tissues was 106% and 96% respectively. Because the mean relative tissue

viability for  PF-01323624 was not below 50% after 3 minutes treatment and not below 15%

after 1 hour treatment  PF-01323624 is considered to be not corrosive.

The absolute mean OD570(optical density at 570  nm)  of the negative control tissues was

within the acceptance limits of OECD 431 (lower acceptance limit ≥0.8 and upper acceptance

limit <_ 2.8) and the laboratory historical control data range (See Appendix 3). The mean

relative tissue viability following the 1-hour exposure to the positive control was 4.1%.

In the range of 20 - 100% viability the Coefficient of Variation between tissue replicates was

<_ 15%, indicating that the test system functioned properly (Appendix 1, Table 3).

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

In conclusion, PF-01323624 is not corrosive in the in vitro skin corrosion test under the
experimental conditions described in this report.

Executive summary:

The objective of this study was to evaluate  PF-01323624 for its ability to induce skin

corrosion on a human three dimensional epidermal model (EpiDerm (EPI-200)). The

possible corrosive potential of  PF-01323624 was tested through topical application for

3 minutes and 1 hour.

The study procedures described in this report were based on the most recent OECD and EC

guidelines.

Batch GR13290 of  PF-01323624 was a white to off-white solid. Skin tissue was moistened

with 25 µL of Milli-Q water and at least 25 mg of  PF-01323624 was applied directly on top

of the skin tissue.

The positive control had a mean relative tissue viability of 4.1% after the 1-hour exposure.

The absolute mean OD570(optical density at 570  nm)  of the negative control tissues was

within the acceptance limits of OECD 431 (lower acceptance limit ≥0.8 and upper acceptance

limit <_ 2.8) and the laboratory historical control data range. In the range of 20 - 100%

viability the Coefficient of Variation between tissue replicates was <_ 15%, indicating that the

test system functioned properly.

Skin corrosion is expressed as the remaining cell viability after exposure to the test item. The

relative mean tissue viability obtained after 3-minute and 1-hour treatments with

PF-01323624 compared to the negative control tissues was 106% and 96%, respectively.

Because the mean relative tissue viability for  PF-01323624 was not below 50% after the

3-minute treatment and not below 15% after the 1-hour treatment  PF-01323624 is considered

to be not corrosive.

In conclusion,  PF-01323624 is not corrosive in the in vitro skin corrosion test under the

experimental conditions described in this report.