N-(2-oxo-1,2-dihydropyrimidin-4-yl)benzamide

Partition coefficient

Administrative data

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Experimental Starting Date: 11 October 2012. Experimental Completion Date: 25 January 2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2013

Report date:

2013

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

EU Method A.8 (Partition Coefficient - Shake Flask Method)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

OECD Guideline 107 (Partition Coefficient (n-octanol / water), Shake Flask Method)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Partition coefficient type:

octanol-water

Test material

Test material information

Constituent 1

Reference substance name:

N4-Benzoylcytosine

EC Number:

628-907-2

Cas Number:

26661-13-2

Molecular formula:

C11H9N3O2

IUPAC Name:

N4-Benzoylcytosine

Specific details on test material used for the study:

Identification: N-Benzoyl Cytosine
Description: Off white powder
Batch: NBC-5-11001
Purity: ≥ 95.0%
Expiry / Retest Date: Not supplied
Storage Conditions: Room temperature in the dark over silica gel

Results and discussion

Partition coefficient

Type:

Pow

Partition coefficient:

0.9

Temp.:

20 °C

pH:

7

Details on results:

Preliminary estimate
The log10 Pow was calculated to be in the range 0.38 to 1.36.

Due to problems developing and validating a suitable analytical procedure for low test item concentrations in n-octanol and water (for the shake flask method), and the test item being particularly insoluble in typical reverse phase HPLC solvents (for the HPLC method), it was considered that the partition coefficient would be better assessed using the ratio of the solubilities of the test item in n-octanol and water (by visual assessment) method.

Any other information on results incl. tables

Definitive test

Solubility in n-Octanol

The sample concentrations, observations and solution pH are shown in the following table:

Sample	Concentration (g/L)	Observation
1	1.04	A clear, colorless solution with excess test item present as sediment.
2	0.109	A clear, colorless solution with excess test item present as sediment.
3	1.08 x 10-2	A clear, colorless solution with a slight amount of excess test item present as sediment.
4	1.34 x 10-3	A clear, colorless solution with a slight amount of excess test item present as sediment.

Overall result: Less than 1.34 x 10-3 g/L at 20.0 ± 0.5 °C.

Solubility in Water

The water solubility was previously determined to be greater than 1.49 x 10-3 g/L of solution at 20.0 ± 0.5 °C.

Partition Coefficient

From the ratio of the solubilities in n-octanol and water, the partition coefficient was estimated to be less than 0.90 at 20.0 ± 0.5 °C, log10 Pow less than -0.05.

Applicant's summary and conclusion

Conclusions:

The partition coefficient of the test item has been determined to be less than 0.90 at 20.0 ± 0.5 °C, log10 Pow less than -0.05.

Executive summary:

Less than 0.90 at 20.0 ± 0.5 °C, log10 Pow less than -0.05, using the ratio of the solubilities of the test item in n-octanol and water (by visual assessment) method, designed to be compatible with Method A8 Partition Coefficient of Commission Regulation (EC) No 440/2008 of 30 May 2008 and Method 107 of the OECD Guidelines for Testing of Chemicals, 27 July 1995.