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Diss Factsheets

Administrative data

Endpoint:
hydrolysis
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2003

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 111 (Hydrolysis as a Function of pH)
Deviations:
no
GLP compliance:
yes (incl. QA statement)

Test material

Constituent 1
Chemical structure
Reference substance name:
2-(1,3-benzodioxol-5-ylamino)ethanol hydrochloride
EC Number:
303-085-5
EC Name:
2-(1,3-benzodioxol-5-ylamino)ethanol hydrochloride
Cas Number:
94158-14-2
Molecular formula:
C9H11NO3.ClH
IUPAC Name:
2-(1,3-benzodioxol-5-ylamino)ethanol hydrochloride
Test material form:
solid: crystalline
Radiolabelling:
no

Study design

Analytical monitoring:
yes

Results and discussion

Transformation products:
not specified
Remarks:
degradation products were not investigated
Dissipation DT50 of parent compoundopen allclose all
Key result
pH:
5
Temp.:
20 °C
Hydrolysis rate constant:
0 s-1
DT50:
205 h
Key result
pH:
5
Temp.:
30 °C
Hydrolysis rate constant:
0 s-1
DT50:
94 h
Key result
pH:
7
Temp.:
20 °C
Hydrolysis rate constant:
0 s-1
DT50:
472 h
Key result
pH:
7
Temp.:
30 °C
Hydrolysis rate constant:
0 s-1
DT50:
491 h
Key result
pH:
9
Temp.:
20 °C
Hydrolysis rate constant:
0 s-1
DT50:
2 594 h
Key result
pH:
9
Temp.:
30 °C
Hydrolysis rate constant:
0 s-1
DT50:
1 266 h

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
For pH 5, 7 and 9 at 50 °C (preliminary test} and at 20 and 30 °C (definitive study}, respectively degradation has been observed and the active ingredient was considered to be hydrolytically unstable. Reaction rate constants and half life times of the definitive study are given in table 17.

Tab. 16: Degradation in [%}] of the Active lngredient of Aminol at 50 oc after 96 h (Preliminary Test)
      pH 5       pH 7       pH 9
Degradation [%]       87       36       20

Tab. 17: Reaction Rate Constants and Half Lifes for the Active lngredient of Aminol of the Definitive Study
      pH 5       pH 7       pH 9
      20 °C       30 °C       20 °C       30 °C       20 °C       30 °C
Reaction rate constant kobs [1/s]       9.40*10-7       2.05*10-6       4.08*10-7       3.92*10-7       7.42*10-8       1.52*10-7
Half-life T1/2 [h]       205       94       472       491       2594       1266
Half-life T1/2 [d]       8.5       3.9       19.7       20.5       108.1       52.8

Executive summary:

Hydrolysis as a function of pH was determined according to OECD-Guideline 111 for Testing of Chemicals (1981) for the test item AMINOL (batch number: R0075037) from 2003-07-14 to 2003-09-12 at DR.U.NOACK-LABORATORIUM FüR ANGEWANDTE BIOLOGIE, Sarstedt, Germany. The study was conducted with a test item concentration of 100 mg/L in buffer solutions of pH 5, 7 and 9 at temperatures of 50 °C (preliminary study) and 20 and 30 °C (definitive study)

, respectively. Samples were taken at test start and test end for the preliminary study and at test start and at minimum 9 spaced points for the definitive study, respectively. Buffer solutions were analysed at test start and test end and there was no interference with the test item. Analyses of the active ingredient 2-(1 ,3-benzodioxol-5-ylamino)ethanolhydrochlorid were performed via HPLC on a C18 column with UV- detection. The active ingredient was found to undergo hydrolysis at pH 5, 7 and 9 at the tested temperatures 20, 30 and 50 °C. respectively (Tab. 1 and 2). Reaction rate constants and half lives of the definitive study are given in Tab. 2. All samples have been analysed directly for degradation products via HPLC and UV-detection at 246 nm. Degradation products were found with significant intensity in samples of pH 7 at 20 °C (after 676.42 h) and 30 oc (after 501.50 and 676.83 h), respectively. Type and structure of the degradation products were not investigated. lt is possible that former formation of degradation products were not recorded by the analytical method. For details please refer to part 4.

Tab. 1: Degradation in [%}] of the Active lngredient of Aminol at 50 oc after 96 h (Preliminary Test)

      pH 5       pH 7       pH 9

Degradation [%]       87       36       20

Tab. 2: Reaction Rate Constants and Half Lifes for the Active lngredient of Aminol of the Definitive Study

      pH 5       pH 7       pH 9

      20 °C       30 °C       20 °C       30 °C       20 °C       30 °C

Reaction rate constant kobs [1/s]       9.40*10-7       2.05*10-6       4.08*10-7       3.92*10-7       7.42*10-8       1.52*10-7

Half-life T1/2 [h]       205       94       472       491       2594       1266

Half-life T1/2 [d]       8.5       3.9       19.7       20.5       108.1       52.8

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