Registration Dossier

Administrative data

Endpoint:
hydrolysis
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2016-11-25 to 2017-03-20
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2017
Report Date:
2017

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 111 (Hydrolysis as a Function of pH)
Version / remarks:
/ EC No. 440/2008 Method C.7
Deviations:
no
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Genamin DMG 75


Radiolabelling:
no

Study design

Analytical monitoring:
yes
Details on sampling:
- Sampling intervals for the parent products:
For the preliminary test, samples were taken at test start (0 h) and test end (120 h). Only a preliminary test was performed.
The incubation temperature was checked automatically once in an hour and at least once per day manually.
Buffers:
Test system
Preliminary test Sterile buffer solutions with pH values 4, 7 and 9 (50 °C).

Buffers were prepared from chemicals with analytical grade or better quality following the composition guidance given in “KÜSTER-THIEL, Rechentafeln für die Chemische Analytik” and the OECD Guideline No. 111, respectively, by direct weighing of the buffer components. Buffers were purged with nitrogen for 5 min and then the pH was checked to a precision of at least 0.1 at the test temperatures. Buffers were sterilised by filtration through 0.2 µm.

Buffer solution pH 4 0.18 g of NaOH and 5.7555 g of mono potassium citrate were dissolved in 500 mL double distilled water.

Buffer solution pH 7 0.3854 g of ammonium acetate were dissolved in 500 mL double distilled water.

Buffer solution pH 9 0.426 g NaOH, 1.8638 g KCl and 1.5458 g H3BO3 were dissolved in 500 mL double distilled water.

Reason for the selection These buffer systems were selected according to the guidelines. The buffer systems were suitable for their pH values.

Details
Chemical Origin Batch number Purity [%]
NaOH VWR 16B290018 ≥97
H3BO3 ROTH 254213812 ≥ 99.5
KCl ROTH 326247542 ≥ 99.5
NH4CH3COO VWR 16C070008 98.4
KH2 Citrate FLUKA BCBH3957V ≥ 98
Double distilled water ROTH 326247375 conductivity: ≤ 2.0 μS/cm
Details on test conditions:
TEST SYSTEM
- Type, material and volume of test flasks, other equipment used: HPLC vials, volume 2 mL
- Measures taken to avoid photolytic effects:Photolytic effects were avoided by using opaque water baths.
- Measures to exclude oxygen: None
- Is there any indication of the test material adsorbing to the walls of the test apparatus? No

TEST MEDIUM
- Volume used/treatment: 1 mL
- Preparation of test medium: The test item was dissolved methanol at 10 g/L and dissolved in respective buffer solution : acetonitrile (95 : 5) to 10 mg/L. 0.945 mL of buffer solutions were spiked with 0.055 mL test item solution at 10 mg/L to a test item concentration of 550 µg/L in the test containers. After the vials were sealed they were transferred into the thermostat. The time between test item application and transfer to thermostat as well as analysis of the start values did not exceed 30 min for all test conditions.

- Incubation:
preliminary test: 2017-03-15 to 2017-03-20 (pH 4, 7 and 9; 50 °C)

- Temperatures:
Preliminary test: 50 ± 0.5 °C

- Sterility:
A check for sterility was not deemed necessary.

- Renewal of test solution: None
Duration of testopen allclose all
Duration:
120 h
pH:
4
Temp.:
50 °C
Initial conc. measured:
594 µg/L
Duration:
120 h
pH:
7
Temp.:
50 °C
Initial conc. measured:
499 µg/L
Duration:
120 h
pH:
9
Temp.:
50 °C
Initial conc. measured:
494 µg/L
Number of replicates:
One sampling at test start and after 120 h.
Positive controls:
no
Negative controls:
yes
Remarks:
buffer solutions (pH 4, 7 and 9)

Results and discussion

Preliminary study:
In the preliminary test less than 10% of the test item degraded after 120 hours at pH 4, 7 and 9.

Degradation [%] at 50 °C after 120 Hours
 
Hydrolysis Time Degradation [%]
[hours] pH 4 pH 7 pH 9
120 0 0 0
Test performance:
CHRONOLOGICAL TEST DESCRIPTION
- Method validation
- Preparation of the (sterile) test solutions (experimental starting)
- Thermostatisation of the test solutions
- Analysis of samples
- Calculations
Transformation products:
no
Dissipation DT50 of parent compound
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; sterility check was deemed to be not necessary due to no significant degradation of the test item

Any other information on results incl. tables

Hydrolysis Results

Hydrolysis Results forthe Test Itemat pH 4 and 50 °C

Hydrolysis Time

[h]

Concentration

[µg/L]

Loss of test item [%]

 

0 594 -
120 598 0.00

Hydrolysis Results forthe Test Itemat pH 7 and 50 °C

Hydrolysis Time

[h]

Concentration

[µg/L]

Loss of test item [%]

 

0 499 -
120 516 0.00

Hydrolysis Results forthe Test Itemat pH 9 and 50 °C 

Hydrolysis Time

[h]

Concentration

[µg/L]

Loss of test item [%]

 

0 494 -
120 513 0.00

 

The test item Genamin DMG 75 was found to be hydrolytically stable at all pH conditions.

pH-Value of the Test Systems

measured before start of hydrolysis

Test

Preliminary

Intended
pH-value

Measured pH‑value

at 50 °C

4.0 ± 0.1

4.01

7.0 ± 0.1

6.90

9.0 ± 0.1

9.01

Temperature of the Test System

The temperature was in good agreement with the nominal range throughout the test. The mean temperature was 50.0 °C with a minimum of 49.8 °C and a maximum of 50.0 °C during the study.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The test item Genamin DMG 75 was found to be hydrolytically stable at all pH conditions.
Executive summary:

Hydrolysis as a function of pH was determined according to OECD Guideline No. 111 and Council Regulation (EC) No. 440/2008, Method C.7 for the test item Genamin DMG 75 (batch number: RAK-KRS-00022) from 2016 -11 -25 to 2017 -02 -20 at Noack Laboratorien GmbH, 31157 Sarstedt, Germany.

 

The study was conducted with test item concentrations of 550 µg/L in buffer solutions at pH 4, 7 and 9 at a test temperature of 50 °C (preliminary test).

 

Samples were taken at test start (0 hours) and test end (120 hours) and analysed via LC-MS/MS on a reversed phase column using an external standard. Buffer solutions were analysed at test start and test end and indicated no interference with the test item. The analytical method for determination of the test item Genamin DMG 75 was validated and tested with satisfactory results in regard to linearity, accuracy, precision and specificity.

 

No significant elimination was observed and therefore the test item was considered as hydrolytically stable under this condition and a half-life of > 1 year could be assumed for environmental typical temperatures.

 

Loss of Test Item [% of applied] ofDuasynAcid VioletSDat 50 °C after 120Hours

 

Hydrolysis Time

[Hours]

Loss of Test Item [%]

pH 4

pH 7

pH 9

120

0.00

0.00

0.00