Registration Dossier

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

Test material

Reference
Name:
Unnamed
Type:
Constituent

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 testopen allclose all
Duration:
120 h
pH:
4
Temp.:
50 °C
Initial conc. measured:
ca. 2 g/L
Duration:
120 h
pH:
7
Temp.:
50 °C
Initial conc. measured:
ca. 2 g/L
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 half-life of parent compoundopen allclose all
pH:
4
Temp.:
50 °C
Half-life:
> 1 yr
pH:
7
Temp.:
50 °C
Half-life:
> 1 yr
pH:
9
Temp.:
50 °C
Half-life:
> 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.