[No public or meaningful name is available]

Hydrolysis

Administrative data

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

key study

Study period:

June 2009 - November 2009

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2009

Report date:

2009

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 111 (Hydrolysis as a Function of pH)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

2-Amino-5-cyano-N,3-dimethylbenzamide

Cas Number:

890707-29-6

Molecular formula:

C10H11N3O

IUPAC Name:

2-Amino-5-cyano-N,3-dimethylbenzamide

Test material form:

solid: particulate/powder

Radiolabelling:

no

Study design

Analytical monitoring:

yes

Details on sampling:

- Sampling intervals for the parent/transformation products:
Hydrolysis samples were collected from each pH after the test solution was placed into the test vessels (0 hour) and at 2 hour, 5 hour, Day 1 and Day 5.

- Sampling intervals/times for pH measurements:
The pH of the buffer solutions were measured after preparation and sterile filtration. The pH was also documented after sample fortification of pH 4, 7 and 9 buffer test solution on Day 0 and Day 5.

- Sampling intervals/times for sterility check:
Sterility was determined at Day 0 for sterile pH 4, 7 and 9 buffer test systems and at day 5 for pH 4, 7 and 9 buffer test system.

- Sample storage conditions before analysis:
All test samples were analyzed on the same day of sampling and stored at -20±1°C until the completion of the entire study.

Buffers:

- pH: 4
- Composition of 0.01 M pH 4 buffer: sodium acetate, acetic acid, final pH adjustments with sodium hydroxide
- pH: 7
- Composition of 0.01 M pH 7 buffer: sodium phosphate (monobasic), sodium phosphate (dibasic), final pH adjustments with sodium hydroxide
- pH: 9
- Composition of 0.01 M pH 9 buffer: boric acid, final pH adjustments with sodium hydroxide

After preparation, the buffer solutions were filtered by passing through a 0.2 μm filter. The pH was verified following sterilization.

Details on test conditions:

TEST SYSTEM
- Type, material and volume of test flasks, other equipment used: 4 mL amber vials with screw caps
- Sterilisation method: 20 minutes at 121°C
- Lighting: Complete darkness
- If no traps were used, is the test system closed/open: Closed system
- Is there any indication of the test material adsorbing to the walls of the test apparatus? No

TEST MEDIUM
- Volume used/treatment: 4.0 mL sterile buffer fortified with test substance at a concentration of 25 mg/L
- Kind and purity of water: Deionized water
- Preparation of test medium:
- Renewal of test solution: No renewal
- Identity and concentration of co-solvent: Acetonitrile, 0.5%

Duration of test

Duration of test 1

Duration:

5 d

pH:

4

Temp.:

50 °C

Initial conc. measured:

21.96 mg/L

Duration of test 2

Duration:

5 d

pH:

7

Temp.:

50 °C

Initial conc. measured:

23.72 mg/L

Duration of test 3

Duration:

5 d

pH:

9

Temp.:

50 °C

Initial conc. measured:

24.97 mg/L

Number of replicates:

Preliminary test: 2 replicates per test system

Results and discussion

Preliminary study:

The preliminary test for hydrolysis of the test substance was conducted at 50 ± 0.5°C in the dark at each of pH 4, 7 and 9 buffer solutions for a period of 5 days.

Analysis of pH 4, 7 and 9 buffer solutions at Day 5 showed >90% of the recovered test item compared to the 0 Hour analysis.

Thus the test substance was considered to be hydrolytically stable.

Test performance:

Due to the results of the preliminary test no further tests were conducted.

Transformation products:

no

Total recovery of test substance (in %)

Total recovery of test substance (in %) 1

% Recovery:

> 90

pH:

4

Temp.:

50 °C

Duration:

ca. 5 d

Total recovery of test substance (in %) 2

% Recovery:

> 90

pH:

7

Temp.:

50 °C

Duration:

ca. 5 d

Total recovery of test substance (in %) 3

% Recovery:

> 90

pH:

9

Temp.:

50 °C

Duration:

ca. 5 d

Dissipation DT50 of parent compound

Key result

Remarks on result:

hydrolytically stable based on preliminary test

Details on results:

TEST CONDITIONS
- pH, sterility, temperature, and other experimental conditions maintained throughout the study: Yes

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

Results obtained in preliminary test clearly indicate that the test submstance was stable over a period of 5 days at 50 ± 5°C which would indicate a DT50 of >1 year at 25°C.

Executive summary:

The present study was conducted to determine the hydrolytic stability of the test substance according to OECD guideline 111 and EEC method C.7.

The preliminary test for hydrolysis of the test substance was conducted at 50 ± 0.5°C in the dark at each of pH 4, 7 and 9 buffer solutions for a period of 5 days.

Based on the preliminary test data generated in this study, the test substance was found hydrolytically stable in pH 4, 7 and 9 buffers at 50 ± 0.5°C.

The results of the preliminary study are summarized below:

1. Analysis of pH 4 buffer solution at Day 5 showed >90% of the recovered test item compared to the 0 Hour analysis.

2. Analysis of pH 7 buffer solution at Day 5 showed >90% of the recovered test item compared to the 0 Hour analysis.

3. Analysis of pH 9 buffer solution showed >90% of the recovered test item compared to the 0 Hour analysis.

Results obtained in preliminary test clearly indicate that the test substance was stable over a period of 5 days at 50 ± 5°C which would indicate a DT50 of >1 year at 25°C.