Development of Chromatographic Technique for Simultaneous Estimation of Lovastatin and Diltiazem Hydrochloride

Rapid, precise, accurate, specific and sensitive reverse phase liquid chromatographic (RP-HPLC) method has been developed for the simultaneous estimation of Diltiazem hydrochloride and Lovastatin in their tablet formulation. The chromatographic method was standardized using a Kromasil C 18 column (300 mm x 4 mm i.d., 10 µm particle size) with UV detection at 237 nm and flow rate of 1 ml/min. The mobile phase consisting of methanol: water (90:10: v/v). The retention time for the Diltiazem hydrochloride and Lovastatin was found to be 4 min and 5.62 min respectively. Propranolol was selected as an internal standard. Good linearity was obtained for the calibration curve of Diltiazem hydrochloride and Lovastatin and was found to be r 2 = 0.9925 and r 2 = 0.9992 respectively. Tablet analysis and recovery results were found to be 99.95±0.79, 99.95±0.79, 99.68±0.34 and 99.65±0.46 for Lovastatin and Diltiazem hydrochloride respectively, where n= 9. Keyword: Diltiazem hydrochloride; Lovastatin; Propranolol; RP-HPLC.