Abstract

A validated stability indicating LC method for vardenafil hydrochloride trihydrate and its related impurities

Author(s): Ch.Krishnaiah, M.Vishnu Murthy, K.S.V.D.Raghavacharyulu, M.V.N.Brahmeshwara Rao, K.Mukkanti, Ramesh kumar

A gradient reversed phase liquid chromatographic method was developed for the quantitative determination of Vardenafil hydrochloride trihydrate process related impurities and intermediates in bulk drugs. The chromatographic separation was achieved on Waters Symmetry shield RP-8, 250  4.6mm, 5m, column. The gradient liquid chromatographicmethod employs two solutions asmobile phaseAand B. The solutionAcontains a mixture of 0.025mMofNaH2PO4H2O, 1.0mLofTri ethylamine in 1000mLofwater (pH 7.5): Acetonitrile (85:15, v/v) and solution B contains a mixture of water: Acetonitrile (22:78, v/v). The flow rate was 1.0 mLmin-1 and the detection wavelength was 240 nm. The method is found to be precise, linear, accurate and also robust. The LODand LOQof impuritieswere ranged from0.0024 to 0.0059gmL-1 and 0.088 to 0.26gmL-1.Vardenafil hydrochloride trihydrate solutions were found to be stable for at least 48 hours. The method was also found to be stability indicating.