Norma Sbarbati Nudelman

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Rabeprazole sodium is a proton pump inhibitor, used in acid-related disorders, like peptic ulcers and gastroesophageal reflux. It is known to be an acid-labile drug, however, few data about its stability under other factors are available. The aim of this work was to study the photodegradation of rabeprazole, to determine its kinetics and to elucidate the(More)
In the acid hydrolysis of diazepam (1), several unusual products, apart from 2-(N-methylamino)-5-chlorobenzophenone (2) and glycine, were isolated. On the assumption that some of those products could arise from further degradation of 2, the reaction of this compound with 0.5-2 M HCl was studied, in 1:1 MeOH-H2O, at 60 and 80 degrees C. Several unexpected(More)
  • N S Nudelman, C Gallardo Cabrera
  • Journal of pharmaceutical and biomedical analysis
  • 2002
A new spectrofluorimetric assay for the photodegradation products of the ansiolytic drug alprazolam is described. Alprazolam was found to be highly photolabile and special care should be taken to avoid light exposure during alprazolam storage and handling. The photostability of alprazolam was evaluated at pH 2.0, 3.6 and 5.0. The drug was exposed to UVA-UVB(More)
Accelerated thermal, hydrolytic, and photochemical degradations of alprazolam were performed under several reaction conditions. The stress studies revealed the photolability of the drug as the most adverse stability factor; the main photodegradation products were isolated and properly characterized as: triazolaminoquinoleine;(More)
Cases of imposex have been reported for some organisms living in areas of the Argentine Atlantic coast. Since this is one of the known effects of the anti-fouling agent tributyltin (TBT), quantitative determinations of organotins in samples of water and sediments collected from sites along the Argentine coast were carried out. Severe cases of imposex were(More)
The photostability of the antihistamine fexofenadine hydrochloride is described. The stress studies revealed the photostability of the drug as the most adverse stability factor. The main photodegradation products were isolated and its structures were elucidated by 1H, 13C, COSY, HSQC, HMBC NMR and mass spectrometry techniques. The drug was exposed to UVC(More)
The purpose of the present work was to study the effects of simulated sunlight conditions on enzyme inactivation and structural damage in dehydrated glassy systems. Freeze-dried samples containing different enzymes (lactase, invertase, lysozyme and amyloglucosidase) were exposed to light using a medium-pressure metal halide HPA 400 W lamp. After 1 h of(More)
The acidic degradation of diazepam in methanolic aqueous solution has been investigated. Apart from the known degradation products, 2-(N-methylamino)-5-chlorobenzophenone and glycine, produced by the hydrolytic cleavage of the benzodiazepinone ring, five novel products were isolated and fully characterized by their spectroscopic features and independent(More)
A tandem reaction between (E)-cinnamaldehyde, 1a, and phenyllithium affording beta-substituted dihydrochalcones was recently reported. NMR spectroscopic studies on the reaction mixture, as well as isotopic exchange reactions and trapping of two intermediates, provide clues on the several mechanistic steps of this new reaction. Extended studies revealed that(More)
The natural attenuation of oil spill contaminated soils, with different exposure times, in Patagonian environment was evaluated by the use of several parameters to quantify the degree of changes in the composition. Column (CC) and gas chromatography (GC); UV-visible and 1H NMR techniques were used to determine compositional and structural indexes. The(More)