N-{[Benzyl(ethyl)amino]-[(chloro-cyano-nitrophenyl)substituted]phenyl}acetamide

Hydrolysis

Link to relevant study record(s)

Reference

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 111 (Hydrolysis as a Function of pH)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Radiolabelling:

no

Analytical monitoring:

no

Buffers:

The test was carried out at three different pH values: 4, 7 and 9.
For this purpose, buffer solutions were prepared using reagent grade chemicals and double distilled water. Applicable buffer systems are described in the Appendix of EC method C.7 (92/69/EC), OECD guideline 111. The acetate buffer pH 4.0, the phosphate buffer pH 7.0 and the borate buffer pH 9.0 were prepared in a concentration of 0.02 M (for pH 4 and 7) and 0.01M for pH 9.

Details on test conditions:

TEST SYSTEM
- Type, material and volume of test flasks, other equipment used: 100 mL volumetric flask
- Sterilisation method: All glassware used was sterilised using autoclave before use. All buffer solutions were sterilised by passing through 0.2 µm sterilised filters. The experiment was performed in laminar flow chamber under aseptic condition.
- Lighting: No lighting
- Measures taken to avoid photolytic effects: The prepared test item solutions taken in amber coloured vials were kept in a dark incubator in order to avoid photolytic effects.
- Measures to exclude oxygen: The buffer solutions were bubbled with nitrogen gas for approximately 5 minutes

TEST MEDIUM
- Volume used/treatment: 1000 µL
- Kind and purity of water: Double distilled water

OTHER TEST CONDITIONS
- Adjustment of pH: The pH of the buffered test item solutions during the reactions were measured after equilibrating the test samples at room temperature using a calibrated pH meter. The pH of the test item solutions was measured on Day 0 and Day 5.

Duration:

120 h

pH:

4

Temp.:

50 °C

Initial conc. measured:

0.5 mg/L

Duration:

120 h

pH:

7

Temp.:

50 °C

Initial conc. measured:

0.5 mg/L

Duration:

120 h

pH:

9

Temp.:

50 °C

Initial conc. measured:

0.5 mg/L

Number of replicates:

2 at each pH-value

Positive controls:

no

Negative controls:

no

Transformation products:

not measured

% Recovery:

87.9

St. dev.:

5.2

pH:

4

Temp.:

50 °C

Duration:

120 h

% Recovery:

98.6

St. dev.:

5.3

pH:

7

Temp.:

50 °C

Duration:

120 h

% Recovery:

82.8

St. dev.:

0.9

pH:

9

Temp.:

50 °C

Duration:

120 h

pH:

4

Temp.:

25 °C

DT50:

> 1 yr

Type:

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

pH:

7

Temp.:

25 °C

DT50:

> 1 yr

Type:

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

pH:

9

Temp.:

25 °C

DT50:

> 1 yr

Type:

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

Details on results:

Limit of Detection (LOD) of the method was 0.01 µg/mL
Limit of Quantitation (LOQ) of the method was 0.05 µg/mL

Validity criteria fulfilled:

yes

Conclusions:

The test item was considered to be hydrolytically stable in pH 4.0, 7.0 and pH 9.0 buffers (t1/2>1 Year)

Executive summary:

The study was performed as per OECD Guideline No. 111 (OECD, 2004) to determine the rate of hydrolysis of the test item FAT 41047/A as afunction of pH at different pH and temperature.

Test item at nominal concentration of about 0.5 mg/L (0.5 µg/mL) in sterile buffer solutions of pH 4.0, 7.0 and 9.0 was incubated for 5 days at 50 ± 0.5 °C in the preliminary test. Hydrolysis reactions were monitored by analyzing the test item concentration at set intervals using an in-house developed and validated HPLC method.

The hydrolysis of test item after 5 days of incubation at 50 ± 0.5°C was 2.6 %, 0.4 % and 7.2 % at pH 4.0, 7.0 and pH 9.0, respectively. The hydrolysis of test item at 50 ± 0.5°C after 5 days was found to be less than 10 % at pH 4.0, 7.0 and 9.0.

Hence the test item was considered to be hydrolytically stable in pH 4.0, 7.0 and pH 9.0 buffers (t1/2>1 Year).

Description of key information

The test item was considered to be hydrolytically stable in pH 4.0, 7.0 and 9.0 buffers (t 1/2 > 1 year).

Key value for chemical safety assessment

Half-life for hydrolysis:

1 yr

at the temperature of:

25 °C

Additional information

The study was performed as per OECD Guideline No. 111 (OECD, 2004) to determine the rate of hydrolysis of the test item FAT 41047/A as afunction of pH at different pH and temperature.

Test item at nominal concentration of about 0.5 mg/L (0.5 µg/mL) in sterile buffer solutions of pH 4.0, 7.0 and 9.0 was incubated for 5 days at 50 ± 0.5°C in the preliminary test. Hydrolysis reactions were monitored by analyzing the test item concentration at set intervals using an in-house developed and validated HPLC method.

The hydrolysis of test item after 5 days of incubation at 50 ± 0.5°C was 2.6 %, 0.4 % and 7.2 % at pH 4.0, 7.0 and pH 9.0, respectively. The hydrolysis of test item at 50 ± 0.5°C after 5 days was found to be less than 10 % at pH 4.0, 7.0 and 9.0.

Hence the test item was considered to be hydrolytically stable in pH 4.0, 7.0 and pH 9.0 buffers (t1/2>1 Year).