Registration Dossier

Administrative data

Endpoint:
hydrolysis
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2017
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Remarks:
Only the preliminary test at 50 °C was performed.
Cross-reference
Reason / purpose:
other: Analytical method.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2018
Report Date:
2018

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 111 (Hydrolysis as a Function of pH)
Version / remarks:
2004
Deviations:
yes
Remarks:
Only the preliminary test at 50 °C was performed.
Qualifier:
according to
Guideline:
EU Method C.7 (Degradation: Abiotic Degradation: Hydrolysis as a Function of pH)
Version / remarks:
2008
Deviations:
yes
Remarks:
Only the preliminary test at 50 °C was performed.
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder
Details on test material:
Test item: 7-ACT
Chemical name: 7-Amino-3-(2-methyl-5,6-dioxo-1,2,5,6-tetrahydro-[1,2,4]triazin-3-ylsulfanylmethyl)-8-oxo-5-thia-1-aza-bicyclo[4.2.0]oct-2-ene-2-carboxylic acid
Batch No.: B364630
Active ingredient content: >99.0 %
CAS No.: 58909-56-1
Appearance: White, weakly odorous powder
Manufacturing date: 15 May 2016
Retest date: 17 May 2017
Storage: Refrigerator (2-8ºC), protected from light
Radiolabelling:
no

Study design

Analytical monitoring:
yes
Details on sampling:
Samples were twofold diluted with the mobile phase (0.5 mL → 1 mL) and analysed by HPLC method.
Buffers:
Buffer solutions:
pH 4.0: 1 mL 0.2 M Sodium hydroxide and 125 mL 0.2M Potassium hydrogen phthalate were diluted to 500 mL with ultrapure water
pH 7.0: 74 mL 0.2 M Sodium hydroxide and 125 mL 0.2 M Potassium dihydrogen phosphate were diluted to 500 mL with ultra-pure water
pH 9.0: 53.5 mL 0.2 M Sodium hydroxide and 125 mL 0.2 M Boric acid and Potassium chloride were diluted to 500 mL with ultra-pure water
Details on test conditions:
Principle of the Method
Sterile aqueous buffer solutions of different pH values are treated with the test item and incubated in the dark for five days at 50±0.5 °C. Concentration of the test substance is determined at the start, after one and five days. If the concentration of the test substance is lower than 10 % of the initial concentration after 1 day, the study will be stopped at this pH value.

Test Conditions:
Hydrolysis was examined at three different pH values: 4.0, 7.0 and 9.0, at 50 °C in the dark.

The hydrolysis reaction was carried out using a dark thermostat to avoid photolytic effects. Nitrogen was bubbled into the water for five minutes before the preparation of the solutions in order to exclude oxygen.

Performance of the Test:
Preparation of the test solutions:
In case of pH 4.0 25 mL of the Stock Solution was diluted to a total volume of 250 mL with the buffer solution.
In case of pH 7.0 and pH 9.0 test solution, about 5 mg of test item was weighted to the nearest 0.01 mg into a volumetric flask and dissolved in the respective buffer solutions to a total volume of 50 mL. This solution was tenfold diluted with the respective buffer solution.
The pH of each test solution was checked with a calibrated pH meter to a precision of 0.001.
Test solutions were transferred into 20 mL headspace–vials under sterile circumstances, under a laminar flow hood. The tubes were entirely filled with the solution. From each test solution three tubes were prepared.
The tubes were thermostated at 50±0.5°C.
Number of replicates:
3
Positive controls:
no

Results and discussion

Preliminary study:
At pH 4 the concentration of the test item was decreased by about 98.5 %, at pH 7 by 91.9 % and at pH 9 the concentration of the test item was decreased by about 99.5 % after 5 days at 50°C.
Transformation products:
not measured
Details on hydrolysis and appearance of transformation product(s):
pH 4: The concentration of the test item decreased at 50 °C to 9 % of the start concentration after 1 day.
pH 7: The concentration of the test item decreased at 50 °C to 30 % of the start concentration after 1 day and to 15 % after 5 days.
pH 9: The concentration of the test item decreased at 50 °C to 64 % of the start concentration after 1 day and to 27 % after 5 days.
Dissipation DT50 of parent compoundopen allclose all
Key result
pH:
4
Temp.:
50 °C
DT50:
< 1 d
Type:
not specified
Key result
pH:
7
Temp.:
50 °C
DT50:
< 1 d
Type:
not specified
Key result
pH:
9
Temp.:
50 °C
DT50:
< 5 d
Type:
not specified

Applicant's summary and conclusion

Conclusions:
pH 4: The concentration of the test item decreased at 50 °C to 9 % of the start concentration after 1 day.
pH 7: The concentration of the test item decreased at 50 °C to 30 % of the start concentration after 1 day and to 15 % after 5 days.
pH 9: The concentration of the test item decreased at 50 °C to 64 % of the start concentration after 1 day and to 27 % after 5 days.
Executive summary:

Hydrolysis of the test item in different pH buffer solutions was determined at 50 °C ± 0.5 °C.

Results:

pH 4: The concentration of the test item decreased at 50 °C to 9 % of the start concentration after 1 day.

pH 7: The concentration of the test item decreased at 50 °C to 30 % of the start concentration after 1 day and to 15 % after 5 days.

pH 9: The concentration of the test item decreased at 50 °C to 64 % of the start concentration after 1 day and to 27 % after 5 days.

Based on the results obtained, the test item can be considered as hydrolytically unstable at pH 4, pH 7 and pH 9 under the conditions investigated.