Stability Indicating Reverse Phase High Performance Liquid Chromatographic Assay for the Determination of Udenafil in Bulk

AbstractA stability-indicating RP-HPLC method was developed for the quantitative determination ofUdenafil in bulk. It involved a Phenomonex C-18 column (250mm × 4.6 mm i.d., 3.5 μm) asstationary phase. The isocratic LC method employs solution A and B as mobile phase.Solution A contains acetonitrile and solution B contains sodium dihydrogen orthophosphatedehydrate buffer in ratio (85:15 v/v) with pH 6.0. The flow rate was 1.0 mL/min and thedetection wavelength was 291 nm. The retention time of Udenafil is about 3.0 ± 0.2 min.Udenafil was subjected to different stress conditions prescribed by the InternationalConference on Harmonization (ICH) guidelines. The drug was subjected to stress conditionsof hydrolysis, oxidation and photolysis degradation. Degradation was found to occur inhydrolytic stress and to some extent in oxidative stress and photolytic conditions. The assayof stress samples was calculated against a qualified reference standard and the percentagedegradation in each condition are reported. The developed RP-HPLC method was partiallyvalidated with respect to specificity and selectivity, linearity, LOD and LOQ.