(undec-10-enoylamino)acetic acid

Hydrolysis

Link to relevant study record(s)

Reference

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP study, EU guideline

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)

Remarks:

2008-26-05

Radiolabelling:

no

Analytical monitoring:

yes

Details on sampling:

Preparation of the abiotic degradation solutions
Preparation of the solutions
For the experiment at pH = 5, a quantity of about 35 mg of the test item was weighed (to the nearest 0.1 mg) into a 100-mL Erlenmeyer. A volume of 50 mL of buffer at pH = 5 was added. The LIPACIDE UG concentration was equal to 700 mg/L (about half the saturation concentration).
A second Erlenmeyer flask was prepared at pH = 5.
For the experiment at pH = 7 and pH = 9, a quantity of about 120 mg of the test item was weighed (to the nearest 0.1 mg) into 100-mL Erlenmeyer flasks. A volume of 50 mL of buffer at pH = 7 or pH = 9 was added. The LIPACIDE UG concentration was equal to 2400 mg/L (about 0.01M as the molecular weight of LIPACIDE UG is equal to 241.3 g/mole).
A second Erlenmeyer flask was prepared for pH = 7 and pH = 9.
In order to dissolve the test item in each buffer solution, the Erlenmeyer flasks were treated 5 min. with ultra-sounds and then heated for about 20 min. at a temperature of about 40 °C.
Sampling for analysis
At T = 0 after dissolution of the test item, a volume of 5 mL of the each of the solutions
was transferred into a glass vial.
The Erlenmeyer flasks were then transferred into a water bath at 50 ± 0.5 °C.
At T = 2.4 h and 5 days
The flasks were taken out of the bath and cooled to room temperature for 3 to 5 minutes
before sampling. The sampling was made like at T = 0.
All the collected samplings were frozen at a temperature of minus 15 °C.
Preparation of the test item solutions for the analysis
After defrosting, the samplings were diluted with the mobile phase
- 10 fold for the samplings issued from the experiment at pH = 5,
- 50 fold for the samplings issued from the experiment at pH = 7 and pH = 9
and then analyzed.
Preparation of the analytical instrumental solutions
Preparation of the stock solution
A stock solution of LIPACIDE UG was prepared at a concentration of about 250 mg/L using the mobile phase as solvent.
Preparation of the instrumental solutions
By serial dilutions with the mobile phase, analytical instrumental solutions containing from 200 to 10 mg/L of LIPACIDE UG were prepared.

Buffers:

Preparation of the buffer solutions for the abiotic hydrolysis Buffer at pH 5: For 100 mL of buffer
A quantity of about 1.02 g of potassium hydrogenophtalate was weighed into a 50-mL volumetric flask, the volume was made with water and the solution was treated with ultrasounds.
A volume of about 18 mL of a sodium hydroxide 0.1M* solution and the above solution were transferred into a 100-mL volumetric flask. The flask was made to volume with water and the pH was verified.
Buffer at pH 7: For 100 mL of buffer
A quantity of about 0.68 g of potassium hydrogenophosphate was weighed into a 50-mL volumetric, the volume was made with water and the solution was treated with ultrasounds.
A volume of about 29 mL of sodium hydroxide 0.1M* and the above solution were transferred into a 100-mL volumetric flask. The flask was made to volume with water and the pH was verified.
Buffer at pH 9: For 100 mL of buffer
A quantity of about 0.38 g of potassium chloride and a quantity of about 0.32 g of boric acid were weighed into a 50-mL flask, the volume was made with water and the solution was treated with ultrasounds..
A volume of about 21.3 mL of a sodium hydroxide 0.1M* solution and the above solution were transferred into a 100-mL volumetric flask. The flask was made to volume with water and the pH was verified.
*The sodium hydroxide solution was at 0.097M.

Duration:

5 d

pH:

9

Initial conc. measured:

ca. 2 468 mg/L

Duration:

5 d

pH:

5

Initial conc. measured:

ca. 710 mg/L

Duration:

5 d

pH:

7

Initial conc. measured:

ca. 2 392 mg/L

Number of replicates:

2

Test performance:

At pH 5, 7 and 9, LIPACIDE UG was practically not hydrolyzed after 5 days.
As in all cases less than 10% hydrolysis of LIPACIDE UG occurs after 5 days, the study was stopped.

Transformation products:

no

pH:

5

Temp.:

50 °C

Hydrolysis rate constant:

< 10

Remarks on result:

other: <10 % hydrolysis

pH:

7

Temp.:

50 °C

Hydrolysis rate constant:

< 10

Remarks on result:

other: <10 % hydrolysis

pH:

9

Temp.:

50 °C

Hydrolysis rate constant:

< 10

Remarks on result:

other: <10 % hydrolysis

Validity criteria fulfilled:

yes

Conclusions:

At pH 5, 7 and 9, LIPACIDE UG was practically not hydrolyzed after 5 days.
As in all cases less than 10% hydrolysis of LIPACIDE UG occurs after 5 days, the study was stopped.

Executive summary:

Abiotic degradation of LIPACIDE UG pH dependent hydrolysis Preliminary assay

In compliance with EEC Directive 92/69 - Method C7 (1992)

The objective of the study was to define the degradation of the test item during a pH dependent hydrolysis.

The results of the abiotic degradation are summarized as following: At pH 5, 7 and 9, LIPACIDE UG was practically not hydrolyzed after 5 days.

As in all cases less than 10% hydrolysis of LIPACIDE UG occurs after 5 days, the study was stopped.

Description of key information

Abiotic degradation of the test item pH dependent hydrolysis Preliminary assay was carried out in compliance with EEC Directive 92/69 - Method C7 (1992).At pH 5, 7 and 9, the test item was practically not hydrolyzed after 5 days.