Registration Dossier

Administrative data

Endpoint:
hydrolysis
Type of information:
experimental study
Adequacy of study:
key study
Study period:
03 May 2005 - 15 June 2005
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:
2006
Report Date:
2006

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
EU Method C.7 (Degradation: Abiotic Degradation: Hydrolysis as a Function of pH)
Deviations:
no
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Radiolabelling:
no

Study design

Analytical monitoring:
yes
Details on sampling:
- Sampling intervals for the parent/transformation products:
0 hrs, 2.4 hrs, 24 hrs and 120 hrs

- Sampling method:
Duplicate aliquots (A and B) of sample material were diluted by a factor of 2 using acetonitrile and the concentration of the parent compound determined by HPLC.

- Sampling intervals/times for pH measurements:
Aliquots of the sample solutions were taken from the flask at 0, 2.4, 24 and 120hrs and the pH of each solution recorded

- Sample storage conditions before analysis:
Sample solutions were prepared in stoppered glass flasks at a nominal concentration of 0.500g/L in the three buffer solutions (pH 4, 7 and 9). The solutions were shielded from light whilst maintained at the test temperature of 50 degrees celsius .
Buffers:
- pH:
4, 7 and 9

- Composition of buffer:- Type and final molarity of buffer:

The Buffer solution of pH 4 contained Potassium hydrogen phthalate at a concentration of 0.005 mol/ L

The Buffer solution of pH 7 contained Disodium hydrogen orthophosphate (anhydrous) at a concentration of 0.003 mol/ L, Potassium dihydrogen orthophosphate at a concentration of 0.002 mol/ L and sodium chloride at a concentration of 0.002 mol/ L.

The Buffer solution of pH 9 contained Disodium tetraborate at a concentration of 0.001 mol/ L and sodium chloride at a concentration of 0.002 mol/ L.

The buffer solutions were filtered through a 0.2um membrane filter to ensure they were sterile before commencement of the test. Also the solutions were subjected to ultrasonication and degassing with nitrogen to minimise oxygen content.
Details on test conditions:
The solutions were shielded from light whilst maintained at the test temperature of 50 degrees celsius.
Duration of testopen allclose all
Duration:
120 h
pH:
9
Temp.:
50
Initial conc. measured:
0.503 g/L
Duration:
120 h
pH:
7
Temp.:
50
Initial conc. measured:
0.498 g/L
Duration:
120 h
pH:
4
Temp.:
50
Initial conc. measured:
0.491 g/L
Number of replicates:
2

Results and discussion

Preliminary study:
Sample solutions at pH 4, 7 and 9 were manintained at 50.0 +/- 0.5 Degrees celsius for a period of 5 days with no degradation observed.
Transformation products:
no
Total recovery of test substance (in %)open allclose all
% Recovery:
ca. 100
pH:
9
Temp.:
50 °C
Duration:
120 h
% Recovery:
ca. 100
pH:
7
Temp.:
50 °C
Duration:
120 h
% Recovery:
ca. 100
pH:
4
Temp.:
50 °C
Duration:
120 h
Dissipation half-life of parent compoundopen allclose all
pH:
9
Temp.:
25 °C
Half-life:
> 1 yr
pH:
7
Temp.:
25 °C
Half-life:
> 1 yr
pH:
4
Temp.:
25 °C
Half-life:
> 1 yr

Any other information on results incl. tables

Sample solutions at pH 4, 7 and 9 were manintained at 50.0 +/- 0.5 Degrees celsius for a period of 5 days with no degradation observed.

Results:

pH 4 at 50.0 +/- 0.5 oC      Time (hours)         
 0 2.4 24  120 
Concentration (g/L)   0.491 0.493  0.496  0.497 
 % of initial  - 100  101  101 

Result at pH 4: Less than 10% hydrolysis after 5 days at 50 oC, equivalent to a half-life greater than 1 year at 25oC.

pH 7 at 50.0 +/- 0.5 oC      Time (hours)         
 0 2.4 24  120 
Concentration (g/L)   0.498 0.499  0.503  0.505 
 % of initial  - 100  101  101 

Result at pH 7: Less than 10% hydrolysis after 5 days at 50 oC, equivalent to a half-life greater than 1 year at 25oC.

pH 9 at 50.0 +/- 0.5 oC      Time (hours)         
 0 2.4 24  120 
Concentration (g/L)   0.503 0.499  0.504  0.500 
 % of initial  - 99.1 100 99.3 

Result at pH 9: Less than 10% hydrolysis after 5 days at 50 oC, equivalent to a half-life greater than 1 year at 25oC.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Remarks:
Study carried out in accordance with method C7 of commission directive 92/69/EEC, without deviations and in accordance with GLP.
Conclusions:
The estimated half-lives of the test material at pH 4, 7 and 9 are to be >1 yr at 25 degrees celsius.
Executive summary:

The preliminary testing has shown that the estimated half-lives of the test material at pH 4, 7 and 9 are to be >1 yr at 25 degrees celsius.