Method Development and Validation for Simultaneous Estimation of Related Impurities of Cilnidipine and Chlorthalidone in Tablet Dosage Form By Rp-Hplc

Abstract

Chlorthalidone drug is a diuretic used to treatment of hypertension disease. The duration of action for the Chlorthalidone drug is the highest in the pharmacology of the drug. Cilnidipine drug is a calcium channel protein inhibitor and blocker. It has also shown neuroprotective effects in a rat focal brain ischemia model by removing free radicals and activating the phosphatidylinositol 3-kinase pathway. A novel HPLC method was developed and validated for the estimation of related impurities of cilnidipine and chlorthalidone in pharmaceutical formulations. The chromatographic separation was carried out by isocratic elution using an Hypersil BDS C18 column (250×4.6mm; 5μ). The mobile phase was composed of phosphate buffer at a pH of 4.0 and acetonitrile in the ratio of 80:20 (V/V) at a flow rate of 1.0 mL/min. The eluents were detected and quantified at a UV detection wavelength of 225 nm. Calibration curves of all analytes in the range of 1-15μg/mL showed a good correlation linearly (r ≥ 0.99) with recovery rate of more than 98% for each analyte. The percentage RSD in intraday, interday precision and ruggedness were found to be less than 5. Small variations in the developed conditions like mobile phase ratio, flow rate, pH and UV wavelength do not influence the results. The detailed quantitative results of this study show that this method is simple, quick, precise, accurate, sensitive, cost-effective and robust. Thus, the method development and validation result confirm that this method be successfully applied for determination and quantification of impurities for the routine quality control analysis in pharmaceutical dosage forms. Extensively limit of detection establishment and limit of quantification are determined. And gradient mode elution also checked for scope of related substances method development for impurities of Chlorthalidone and Cilnidipine drug components, however known impurities need to be monitored.