Kinetics of the degradation of indomethacin and acemethacin in basic medium
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1
Universidad de Burgos
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2
Universidad de Valladolid
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ISSN: 0037-8968, 1878-7126
Año de publicación: 1991
Volumen: 128
Páginas: 314-318
Tipo: Artículo
Otras publicaciones en: Bulletin de la Société Chimique de France
Resumen
The kinetics of degradation of indomethacin and acemethacin was investigated in basic aqueous media at several temperatures between 20 and 50-degrees-C. Fast polarography, linear sweep voltammetry and UV-VIS spectroscopy were used to obtain the observed first-order rate constants. The rate constant / hydroxide-ion concentration profile was linear with a slope equal to unity, suggesting the relationship: k(obs) = k2 [OH-]. Activation energies and other related parameters were calculated from Arrhenius-type plots. An acceptable scheme for the decomposition of both substances is proposed. The kinetic data obtained from both techniques are in very good agreement and point to the same conclusions. From the half-life times, acemethacin is inferred to be the most stable of the two drugs.