1H-Pyrazolo[3,4-c]pyridine-3-carboxylic acid, 4,5,6,7-tetrahydro-1-(4-methoxyphenyl)-7-oxo-6-[4-(2-oxo-1-piperidinyl)phenyl]-, ethyl ester

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

25 September to 11 October, 2003

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2003

Report date:

2004

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: EPA 712-C-03-197

Test guideline 3

Qualifier:

equivalent or similar to guideline

Guideline:

EU Method B.42 (Skin Sensitisation: Local Lymph Node Assay)

Version / remarks:

no yet approved EU method in 2003

GLP compliance:

yes

Remarks:

OECD ENV /MC/CHEM(98)17

Type of study:

mouse local lymph node assay (LLNA)

Test material

Test material information

Constituent 1

Reference substance name:

ethyl 1-(4-methoxyphenyl)-7-oxo-6-[4-(2-oxopiperidin-1-yl)phenyl]-1H,4H,5H,6H,7H-pyrazolo[3,4-c]pyridine-3-carboxylate

EC Number:

700-890-7

Cas Number:

503614-91-3

Molecular formula:

C27 H28 N4 O5

IUPAC Name:

ethyl 1-(4-methoxyphenyl)-7-oxo-6-[4-(2-oxopiperidin-1-yl)phenyl]-1H,4H,5H,6H,7H-pyrazolo[3,4-c]pyridine-3-carboxylate

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

In vivo test system

Test animals

Species:

mouse

Strain:

other: CBA/Ca

Sex:

female

Details on test animals and environmental conditions:

At the start of the study the mice were in the weight range of 19.3 grams to 24.0 grams and were 8 - 12 weeks weeks old prior to dosing on Day1. Animlas were acclimatised for 8 days prior to the study.
They were housed individually in polycarbonae cages with woodflake Free access to drinking water and standard laboratory rodent diet food was allowed. The temperature and relative humidity were set to achieve limits of 21 ± 2°C and 40 - 70% respectively. The lighting was controlled by a time switch to give 12 hours of artificial light in each 24 hour period.

Study design: in vivo (LLNA)

Vehicle:

acetone/olive oil (4:1 v/v)

Remarks:

select appropriate one

Concentration:

test material at concentrations of 5%, 10% or 25% w/w

No. of animals per dose:

Three groups of five animals each were treated at each concentration group and a further group of five animals were treated as a control group with acetone/olive oil alone.

Details on study design:

The mice were treated by daily application of 25 μl of the appropriate concentration of the test material to the dorsal surface of each ear for three consecutive days (Days 1, 2, 3) by using a micropipette whose tip is used to spread the formulation over the dorsal surface of each ear. On Day 6 all mice were injected with 250 ul of a phophate buffered saline solution containing 3H-methyl thymidine (3HTdR ), 80 µCi/ml to the tail vein. All animals were observed twice daily for signs of ill health. The ears were also examined for signs of ittitation. Body weights of each mouse were recorded before dosing and before termination. Five hours after administration of 3HTdR (Day 6 ) all mice were killed by carbon dioxide asphyxiation and their draining auricular lymph nodes were excised. 1 ml of phosphate buffered saline was added to each set of lymph nodes. Preparation of a single cell suspension was completed for the lymph nodes cells for each individual animal following standard procedures. Determination of the 3HTdR incorporation was completed by measuring radioactive disintegration for each animal's lymph node cells by using a beta-scintillation counter.

Positive control substance(s):

hexyl cinnamic aldehyde (CAS No 101-86-0)

Statistics:

Analysis of variance (ANOVA) was carried out on the data followed by Barlett's test for analysis of homogenicity of variance.

Results and discussion

Positive control results:

α-Hexylcinnamaldehyde, was considered to be a sensitiser under the conditions of the test with test control ratio obtained for 25% v/v HCA at 8.4.

In vivo (LLNA)

Results

Results 1

Parameter:

SI

Value:

1.2

Test group / Remarks:

5% w/v

Results 2

Parameter:

SI

Value:

0.9

Test group / Remarks:

10 % w/v

Results 3

Parameter:

SI

Value:

0.5

Test group / Remarks:

25% w/v

Any other information on results incl. tables

There were no deaths and no signs of ill health or toxicity observed during the study. Greasy fur was noted for all control and test animals and particles on the ears was noted post dose from day 1. These signs had resolved completely by day 5. Bodyweight increases were recorded for all mice over the period of the study.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Based on the results of this study the test material is not regarded as a potential skin sensitizer.

Executive summary:

The test/control ratios obtained for 5, 10 and 25% w/v BMS 589154-01 were 1.2, 0.9 and 0.5 respectively. As a test/control ratio 3 or more was not recorded for any of the concentrations tested, BMS 589154 -01 is not considered to have the potential to cause skin sensitization (delayed hypersensitivity).