The stability of biapenem and structural identification of impurities in aqueous solution.
ABSTRACT The stability of biapenem in aqueous solution was investigated. Forced degradation of biapenem was carried out under different concentrations, pH values and temperatures. The degradation products were determined by reverse-phase HPLC and identified by LC-MS/MS. One dimeric impurity was obtained by reverse-phase preparative HPLC and characterized by LC-MS/MS and NMR. A possible degradation mechanism has been presented.
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ABSTRACT: The catalytic effect of buffers (phosphate, acetate, borate, carbonate) on the degradation of doripenem in aqueous solutions was studied at 313 K in the pH range 0.82–11.56 (μ = 0.50 mol L−1) by an HPLC-UV method developed for kinetic studies of doripenem. It was observed that general acid–base catalysis occurred in all buffers and so catalytic rate constants were calculated. Specific acid–base catalysis of doripenem involved degradation of protonated molecules and zwitter ions of doripenem catalyzed by hydrogen ions, spontaneous degradation of zwitter ions under the influence of water and degradation of zwitter ions and monoanions catalyzed by hydroxide ions.Reaction Kinetics, Mechanisms and Catalysis 01/2011; 102(1):37-47. · 1.10 Impact Factor
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ABSTRACT: The elaborated method of micellar electrokinetic chromatography (MEKC) used to separate biapenem from its related substances was successfully implemented using sweeping under an enhanced electric field, followed by UV absorption detection at 200nm. The best results were obtained with formic buffer (22.5mM) pH 4.3 and sodium dodecyl sulfate (150mM) added to the electrolyte as the sweeping agent. Neutral capillary (60/50cm; 50μm ID) with reverse polarity and voltage values of 22kV, were used throughout the investigation. The optimized method of biapenem determination, validated in terms of linearity, accuracy and precision, provides a detection limit of 0.5μg/mL at S/N=3 for biapenem. The repeatability of the CE system, expressed by relative standard deviations (RSD) in the migration times, for biapenem and its degradation products varied from 0.14 to 1.48%, whereas for the corrected peak areas RSD were about 0.68-8.43%. Satisfactory separation was achieved within 20min of electrophoresis; moreover all carbapenems (imipenem, meropenem, ertapenem, doripenem and biapenem) were separated from each other during analysis. The evaluated MEKC method was applied to the analysis of a medicinal product containing biapenem - Omegacin 0.3g for intravenous drip infusion.Journal of chromatography. A 03/2013; 1282:153-60. · 4.19 Impact Factor
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ABSTRACT: This review describes an epigrammatic impression of the recent trends in analytical perspectives of degradation and impurities profiling of pharmaceuticals including active pharmaceutical ingredient (API) as well as drug products during 2008-2012. These recent trends in forced degradation and impurity profiling were discussed on the head of year of publication; columns, matrix (API and dosage forms) and type of elution in chromatography (isocratic and gradient); therapeutic categories of the drug which were used for analysis. It focuses distinctly on comprehensive update of various analytical methods including hyphenated techniques for the identification and quantification of thresholds of impurities and degradants in different pharmaceutical matrices.Journal of pharmaceutical and biomedical analysis 07/2013; 86C:11-35. · 2.45 Impact Factor