Liquid-Chromatography Determination of Impurities in Sildenafil Citrate

摘要

A simple, economic and time-efficient stability-indicating, reversed phase liquid chromatographic (RP-LC) method has been developed for the analysis of sildenafil citrate in the presence of both process related impurities and degradation products generated by decomposition. The drug was subjected to stress conditions of hydrolysis, oxidation, photolysis and thermal degradation. Considerable degradation was found to occur in alkali and oxidative stress conditions. The drug was found to be stable to other stress conditions attempted. The stress samples were assayed against a qualified reference standard and the mass balance was found close to 99.6 %. The method was validated with respect to specificity, linearity, accuracy, precision, robustness, limit of detection and quantification. The method is simple, rapid, selective, accurate and stability indicating, useful in the quality control of bulk manufacturing of sildenafil.