Kinetic and mechanistic studies on the hydrolysis and photodegradation of diazepam and alprazolam
The corresponding o-aminobenzophenones are usually reported as the main degradation products in the hydrolysis of 1,4-benzodiazepinones. Nevertheless, in previous studies of diazepam (DZ) in acidic aqueous medium we isolated and characterized seven unexpected degradation products. Kinetic measuremen...
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todo:paper_08943230_v18_n2_p156_Cabrera2023-10-03T15:41:59Z Kinetic and mechanistic studies on the hydrolysis and photodegradation of diazepam and alprazolam Cabrera, C.G. Goldberg De Waisbaum, R. Nudelman, N.S. Alprazolam Anxiolytics Benzodiazepinone pharmaceuticals Diazepam Drug stability Hydrolysis Photosensitivity Photostability Electron transitions Mass spectrometry Nuclear magnetic resonance spectroscopy Oxidation pH effects Photodegradation Photosensitivity Reaction kinetics Alprazolam Anxiolytics Benzodiazepinone pharmaceuticals Diazepam Drug stability Photostability Hydrolysis The corresponding o-aminobenzophenones are usually reported as the main degradation products in the hydrolysis of 1,4-benzodiazepinones. Nevertheless, in previous studies of diazepam (DZ) in acidic aqueous medium we isolated and characterized seven unexpected degradation products. Kinetic measurements under several reaction conditions shed some light on the mechanisms of the complex reactions that are taking place, and photochemical studies give hints on the mechanisms of chlorination and annelation processes. Alprazolam (AL) seems to exhibit an unusually high stability against hydrolysis under several conditions; nevertheless, the structure is sensitive to photolytic cleavage. The photodegradation of AL was studied in aqueous and methanolic solutions. Characterization of the isolated products by 1H and 13C NMR and mass spectrometry revealed that electron transfer, oxidation and rearrangement reactions take place. The influence of several variables such as pH, solvent composition and light irradiation were examined and mechanisms for the formation of three photoproducts are proposed. A specific method for the determination of AL in the presence of photoproducts was developed, which allowed kinetic determinations of the photostability of AL. The photosensitivity observed in some patients treated with AL seems to be due to one of the characterized photoproducts. Copyright © 2004 John Wiley & Sons, Ltd. Fil:Goldberg De Waisbaum, R. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_08943230_v18_n2_p156_Cabrera |
institution |
Universidad de Buenos Aires |
institution_str |
I-28 |
repository_str |
R-134 |
collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
topic |
Alprazolam Anxiolytics Benzodiazepinone pharmaceuticals Diazepam Drug stability Hydrolysis Photosensitivity Photostability Electron transitions Mass spectrometry Nuclear magnetic resonance spectroscopy Oxidation pH effects Photodegradation Photosensitivity Reaction kinetics Alprazolam Anxiolytics Benzodiazepinone pharmaceuticals Diazepam Drug stability Photostability Hydrolysis |
spellingShingle |
Alprazolam Anxiolytics Benzodiazepinone pharmaceuticals Diazepam Drug stability Hydrolysis Photosensitivity Photostability Electron transitions Mass spectrometry Nuclear magnetic resonance spectroscopy Oxidation pH effects Photodegradation Photosensitivity Reaction kinetics Alprazolam Anxiolytics Benzodiazepinone pharmaceuticals Diazepam Drug stability Photostability Hydrolysis Cabrera, C.G. Goldberg De Waisbaum, R. Nudelman, N.S. Kinetic and mechanistic studies on the hydrolysis and photodegradation of diazepam and alprazolam |
topic_facet |
Alprazolam Anxiolytics Benzodiazepinone pharmaceuticals Diazepam Drug stability Hydrolysis Photosensitivity Photostability Electron transitions Mass spectrometry Nuclear magnetic resonance spectroscopy Oxidation pH effects Photodegradation Photosensitivity Reaction kinetics Alprazolam Anxiolytics Benzodiazepinone pharmaceuticals Diazepam Drug stability Photostability Hydrolysis |
description |
The corresponding o-aminobenzophenones are usually reported as the main degradation products in the hydrolysis of 1,4-benzodiazepinones. Nevertheless, in previous studies of diazepam (DZ) in acidic aqueous medium we isolated and characterized seven unexpected degradation products. Kinetic measurements under several reaction conditions shed some light on the mechanisms of the complex reactions that are taking place, and photochemical studies give hints on the mechanisms of chlorination and annelation processes. Alprazolam (AL) seems to exhibit an unusually high stability against hydrolysis under several conditions; nevertheless, the structure is sensitive to photolytic cleavage. The photodegradation of AL was studied in aqueous and methanolic solutions. Characterization of the isolated products by 1H and 13C NMR and mass spectrometry revealed that electron transfer, oxidation and rearrangement reactions take place. The influence of several variables such as pH, solvent composition and light irradiation were examined and mechanisms for the formation of three photoproducts are proposed. A specific method for the determination of AL in the presence of photoproducts was developed, which allowed kinetic determinations of the photostability of AL. The photosensitivity observed in some patients treated with AL seems to be due to one of the characterized photoproducts. Copyright © 2004 John Wiley & Sons, Ltd. |
format |
JOUR |
author |
Cabrera, C.G. Goldberg De Waisbaum, R. Nudelman, N.S. |
author_facet |
Cabrera, C.G. Goldberg De Waisbaum, R. Nudelman, N.S. |
author_sort |
Cabrera, C.G. |
title |
Kinetic and mechanistic studies on the hydrolysis and photodegradation of diazepam and alprazolam |
title_short |
Kinetic and mechanistic studies on the hydrolysis and photodegradation of diazepam and alprazolam |
title_full |
Kinetic and mechanistic studies on the hydrolysis and photodegradation of diazepam and alprazolam |
title_fullStr |
Kinetic and mechanistic studies on the hydrolysis and photodegradation of diazepam and alprazolam |
title_full_unstemmed |
Kinetic and mechanistic studies on the hydrolysis and photodegradation of diazepam and alprazolam |
title_sort |
kinetic and mechanistic studies on the hydrolysis and photodegradation of diazepam and alprazolam |
url |
http://hdl.handle.net/20.500.12110/paper_08943230_v18_n2_p156_Cabrera |
work_keys_str_mv |
AT cabreracg kineticandmechanisticstudiesonthehydrolysisandphotodegradationofdiazepamandalprazolam AT goldbergdewaisbaumr kineticandmechanisticstudiesonthehydrolysisandphotodegradationofdiazepamandalprazolam AT nudelmanns kineticandmechanisticstudiesonthehydrolysisandphotodegradationofdiazepamandalprazolam |
_version_ |
1807319245181157376 |