1,3-Diazaspiro[4.5]decane-2,4-dione, 8-methoxy-, sodium salt (1:1), cis-

Hydrolysis

Administrative data

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2007

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2007

Report date:

2007

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 111 (Hydrolysis as a Function of pH)

Version / remarks:

2004

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

1992

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

sodium (5s,8s)-8-methoxy-2,4-dioxo-1,3-diazaspiro[4.5]decan-3-ide

EC Number:

929-513-6

Cas Number:

1400584-86-2

Molecular formula:

C9H13N2O3 · Na

IUPAC Name:

sodium (5s,8s)-8-methoxy-2,4-dioxo-1,3-diazaspiro[4.5]decan-3-ide

Test material form:

solid: bulk

Radiolabelling:

no

Study design

Analytical monitoring:

yes

Details on sampling:

Preparation of Test Samples
Solutions of the test item were prepared by weighting between 9.72 mg and 10.86 mg of the test item in a 100 mL volumetric flask and diluted with the relevant buffer. The resulting solution was subjected immediately to the hydrolysis procedure.

Buffers:

pH 4:
21.008 g citric acid monohydrate were dissolved in 200 mL sodium hydroxide solution (c = 1 mol/L). This solution was filled up to a volume of 1000 mL with distilled water. 44 mL ofhydrochloric acid (c = 1 mol/L) were added to 560 mL of this solution and filled up to a volume of 1000 mL with distilled water. The solution was adjusted to pH 4.0 with sodium hydroxide or hydrochloric acid.

pH 7:
13.61 g potassium dihydrogen phosphate were dissolved in 1000 mL distilled water. 29.63 mL of sodium hydroxide solution (c = 1 mol/L) were added to 500 mL of this solution and filled up to volume of 1000 mL with distilled water. The solution was adjusted to pH 7.0 with sodium hydroxide or hydrochloric acid.

pH 9:
7.46 g potassium chloride and 6.184 g boric acid were dissolved in 1000 mL distilled water. 500 mL of this solution were added to 21.30 mL sodium hydroxide solution (c = 1 mol/L) and filled up to a volume of 1000 mL with water. The solution was adjusted to pH 9.0 with sodium hydroxide or hydrochloric acid.

Positive controls:

no

Negative controls:

yes

Results and discussion

Transformation products:

no

Dissipation DT50 of parent compound

Dissipation DT50 of parent compound 1

Key result

pH:

4

Temp.:

25 °C

DT50:

> 1 yr

Type:

(pseudo-)first order (= half-life)

Dissipation DT50 of parent compound 2

Key result

pH:

7

Temp.:

25 °C

DT50:

> 1 yr

Type:

(pseudo-)first order (= half-life)

Dissipation DT50 of parent compound 3

Key result

pH:

9

Temp.:

25 °C

DT50:

> 1 yr

Type:

(pseudo-)first order (= half-life)

Details on results:

At 25 °C according to the guideline a half-life period of above one year at pH 4, pH 7 and pH 9 may be estimated.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

At 25 °C according to the guideline a half-life period of above one year at pH 4, pH 7 and pH 9 may be estimated.

Executive summary:

The objective of this study was the determination of the abiotic degradation of the test item (the main compound), i.e. the determination of the hydrolysis rate as a function of the pHvalue according to guideline 92/69/EEC, appendix, C.7. and OECD-Guideline 111.

The decomposition rates at pH 4, pH 7 and pH 9 were clearly below 10 % after 5 days at 50°C. Thus the test item may be considered hydrolytically stable at pH 4, pH 7 and pH 9.

At 25 °C according to the guideline a half-life period of above one year at pH 4, pH 7 and pH 9 may be estimated. 

pH value	Half life perior (25°C
4	> 1 year
7	> 1 year
9	> 1 year