(S)-3-methyl-2-(2-oxotetrahydropyrimidine-1-yl)butyric acid

Hydrolysis

Administrative data

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

key study

Study period:

June 16-21 1999

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study carried out in accordance with method C7 of commission directive 92/69/EEC and in accordance with GLP. The test material was well characterised

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1996

Report date:

1999

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

EU Method C.7 (Degradation: Abiotic Degradation: Hydrolysis as a Function of pH)

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

-

EC Number:

430-900-2

EC Name:

-

Cas Number:

192725-50-1

Molecular formula:

Hill formula: C9H16N2O3 CAS formula: C9H16N2O3

IUPAC Name:

3-methyl-2-(2-oxo-1,3-diazinan-1-yl)butanoic acid

Study design

Analytical monitoring:

yes

Details on sampling:

samples taken at 0,2,4,6,24,48 and 120 hours after preparation. After dilution in a 1:20 ratio mobile phase, 1 mL of each sample waspipetted into glass vials and placed i the autosampler rack for automatic injection into the HPLC system.

The values of pH of each solution were measured and recorded at the start and at the end of the test

Buffers:

pH 4 buffer solution:
4.0 ml of 0.1 N NaOH with 500 mL of 0.1 M potassium hydrogen phthalate

pH 7 buffer solution:
296.3 mL of 0.1 N NaOH with 500 mL of 0.1 M potassium dihydrogen phosphate

pH 9 buffer solution
213.0 mL of 0.1 N NaOH with 500 mL of 0.1 M boric acid

Details on test conditions:

performed at 50 C and pH 4, 7.00 and 9

Duration of test

Duration of test 1

Duration:

120 h

pH:

4

Temp.:

50 °C

Initial conc. measured:

ca. 2 g/L

Duration of test 2

Duration:

120 h

pH:

7

Temp.:

50 °C

Initial conc. measured:

ca. 2 g/L

Duration of test 3

Duration:

120 h

pH:

9

Temp.:

50 °C

Initial conc. measured:

ca. 2 g/L

Number of replicates:

three

Negative controls:

yes

Remarks:

buffer solutions at pH 4,7,9

Results and discussion

Preliminary study:

On the basis of the data obtained, the degradation half-life was assumed to be higher than 1 year in the environment.

Test performance:

Regarding the concentrations tested, good precision values were obtained, ranging from 0.01 to 1.4 5, while the accuracy values, excluding the lowest concentration assayed, ranged from 95.68 to 106.07 %. or the concentration levelat 0.01 g/L an acuracy value of 65.03 % was found (in RBM Exp. No. 990238, 101.1 % acuracy was found at 10 mg/L)

with the exception of this accuracy value all the other concentrations showed accuracy and precision values within the acceptance intervals of 85-115% and 0-15% repsectivley.

Transformation products:

not specified

Details on hydrolysis and appearance of transformation product(s):

no transformation products noted

Dissipation DT50 of parent compound

Dissipation DT50 of parent compound 1

pH:

4

Temp.:

50 °C

DT50:

> 1 yr

Dissipation DT50 of parent compound 2

pH:

7

Temp.:

50 °C

DT50:

> 1 yr

Dissipation DT50 of parent compound 3

pH:

9

Temp.:

50 °C

DT50:

> 1 yr

Details on results:

On the basis of the data obtained, the degradation half-life was assumed to be higher than 1 year in the environment.
The degradation curves obtained in this test indicated that A-164220.0 was significantly hydrolyzed in the conditions applied.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

An abiotic degradation study was carried out on A-164220.0 at three different pH values (4, 7 and 9) and at the temperature of 50 +/- 1 °C to evaluate the constant of hydrolysis and the half-life values. A Preliminary test was carried out to evaluate whether the half-life values were lower than 1 day or higher than 1 year for the three pH values. The degradation curves obtained in this test indicated that A-164220.0 was not significantly hydrolyzed in the conditions applied. On the basis of the data obtained, the degradation half-life was assumed to be higher than 1 year in the environment.