N2-acetyl-N-benzyl-O-methyl-L-serinamide

Hydrolysis

Administrative data

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

key study

Study period:

19 Jan 2018 - 29 Jan 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Cross-reference

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Report date:

2018

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

2016

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

OECD Guideline 111 (Hydrolysis as a Function of pH)

Version / remarks:

2004

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPPTS 835.2120 (Hydrolysis of Parent and Degradates as a Function of pH at 25°C)

Version / remarks:

2008

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

2-(acetylamino)-N-benzyl-3-methoxypropanamide

EC Number:

700-539-8

Cas Number:

175481-26-2

Molecular formula:

C13H18N2O3

IUPAC Name:

2-(acetylamino)-N-benzyl-3-methoxypropanamide

Test material form:

solid: particulate/powder

Details on test material:

- Appearance: White powder

Radiolabelling:

no

Study design

Analytical monitoring:

yes

Remarks:

(by UPLC-UV)

Details on sampling:

PREPARATION OF THE SAMPLES
- The test item was spiked to the buffers to the target concentration of 10 mg/L.
- For each sampling time, duplicate vessels under vacuum were filled with 6 mL test solution.
- The vessels were placed in a temperature controlled environment in the dark.
- Blank buffers containing a similar content of blank spiking solution were treated similarly as the test samples (at t=0).

SAMPLING DETAILS
- Samples for analysis were taken immediately after preparation (t=0) and at t= 5 days.
- Samples taken at t=5 days were cooled to room temperature using running tap water.

pH MEASUREMENTS
The pH of the test solutions (except for the blanks) was determined at each sampling point.

Buffers:

Buffer pH 4: 16.7% 0.1 M sodium acetate and 83.3% 0.1 M acetic acid in water.

Buffer pH 7: 0.1 M potassium di-hydrogenphosphate in water adjusted to pH 7 using 1 N sodium hydroxide.

Buffer pH 9: 0.1 M boric acid and 0.1 M potassium chloride in water adjusted to pH 9 using 10 N sodium hydroxide.

Details:
- Kind of water: tap water purified by a purification system (Milli-Q, Millipore)
- Sodium azide content: 0.0009% (w/v)

Details on test conditions:

TEST SYSTEM
- Sterilisation method: Each buffer was filter-sterilised through a 0.2 µm FP 30/0.2 CA-S filter (Whatman) and transferred into a sterile vessel.
- Measures to exclude oxygen: nitrogen gas was purged through the sterile buffers for 5 minutes prior to preparation of the blank and test solutions.
- Measures taken to avoid photolytic effects: the test vessels were kept in the dark.

SPIKING SOLUTION
Spiking solution: test substance in acetonitrile. The spiking volume was < 1% of the sample volume. Nominal concentrations were not corrected for the spiking volume.

DETAILS TIER 1 STUDY
pH 4.0, pH 7.0 and pH 9.0 at 49.9 ± 0.1°C

Duration of test

Duration of test 1

Duration:

5 d

pH:

4

Temp.:

50 °C

Initial conc. measured:

10.2 mg/L

Remarks:

Initial conc. measured: see table in Results.

Duration of test 2

Duration:

5 d

pH:

7

Temp.:

50 °C

Initial conc. measured:

10.2 mg/L

Remarks:

Initial conc. measured: see table in Results.

Duration of test 3

Duration:

5 d

pH:

9

Temp.:

50 °C

Initial conc. measured:

ca. 10.2 mg/L

Remarks:

Initial conc. measured: see table in Results.

Number of replicates:

Two

Positive controls:

no

Negative controls:

no

Results and discussion

Preliminary study:

At pH 4, 7 and pH 9, a degree of hydrolysis < 10% was observed after 5 days at 50°C (half-life time at 25°C is > 1 year).

No further tests were required.

Test performance:

RECOVERIES
- Recovery is the concentration analysed at t=0 relative to the nominal concentration.
- The mean (n=2) recovery at each pH was calculated (see table below).
- The mean recoveries fell within the criterion range of 90-110%.
- Concentrations analysed in the test samples were not corrected for recovery.

Transformation products:

no

Details on hydrolysis and appearance of transformation product(s):

not applicable

Total recovery of test substance (in %)

Total recovery of test substance (in %) 1

% Recovery:

100

pH:

4

Temp.:

50 °C

Remarks on result:

other: actual recovery: 102%

Total recovery of test substance (in %) 2

% Recovery:

100

pH:

7

Temp.:

50 °C

Remarks on result:

other: actual recovery: 102%

Total recovery of test substance (in %) 3

% Recovery:

100

pH:

9

Temp.:

50 °C

Remarks on result:

other: actual recovery: 101%

Dissipation DT50 of parent compound

Dissipation DT50 of parent compound 1

Key result

pH:

4

Temp.:

25 °C

DT50:

> 1 yr

Remarks on result:

hydrolytically stable based on preliminary test

Dissipation DT50 of parent compound 2

Key result

pH:

7

Temp.:

25 °C

DT50:

> 1 yr

Remarks on result:

hydrolytically stable based on preliminary test

Dissipation DT50 of parent compound 3

Key result

pH:

9

Temp.:

25 °C

DT50:

> 1 yr

Remarks on result:

hydrolytically stable based on preliminary test

Any other information on results incl. tables

Additional alternative matrices test

- The mean accuracy at each concentration level fell in the range 70-110% (see table below).

- Repeatability at each concentration level: see also table below

Conclusion: the analytical method was accepted for the analysis of the substance in the 3 buffer solutions in the target concentration range of 0.1 – 100 mg/L.

Matrix	Concentration [mg/L]			Accuracy [%]		Coefficient of variation [%]
	Target	Nominal	Analyzed	Individual	Mean
Buffer pH 4	0.1	0.100	0.0901	90	90	n.a.
		0.100	0.0905	91
	100	100	99.7	100	99	n.a.
		100	98.3	98
Buffer pH 7	0.1	0.100	0.0887	89	88	1.2
		0.100	0.0868	87
		0.100	0.0865	86
		0.100	0.0873	87
		0.100	0.0888	89
	100	100	99.3	99	99	0.90
		100	100	100
		100	98.0	98
		100	98.8	99
		100	100	100
Buffer pH 9	0.1	0.100	0.0883	88	88	n.a.
		0.100	0.0881	88
	100	100	98.7	99	98	n.a.
		100	97.9	98

n.a.: Not applicable

Table: Tier 1 results:

pH	Sampling time	Analyzed concentration [mg/L]	Degree of hydrolysis [%]		pH
			Individual	Mean
pH 4	0 hours	10.2			4.0
		10.2			4.0
	5 days	10.1	0.53	0.37	4.0
		10.2	0.22		4.0
pH 7	0 hours	10.2			7.1
		10.2			7.1
	5 days	10.1	1.1	0.92	7.1
		10.1	0.70		7.1
pH 9	0 hours	10.1			9.0
		10.2			9.0
	5 days	10.0	0.94	1.1	9.0
		10.0	1.3		9.0

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The substance is hydrolytically stable at pH 4, 7 and 9 (half-life time at 25°C: > 1 year).

Executive summary:

The hydrolysis study at pH values normally found in the environment (pH 4, 7 and 9) was performed in a GLP-compliant study according to EC C.7, OECD 111 and EPA OPPTS 835.2120. A degree of < 10% of hydrolysis was observed at pH 4, 7 and 9 after 5 days at 50°C (Tier 1). This corresponds with a half-life time at 25°C of > 1 year. The substance is concluded to be hydrolytically stable at pH 4, 7 and 9.