Validated HPLC Method for Simultaneous Quantitation of Diclofenac Sodium and Misoprostol in Bulk Drug and Formulation

HPLC method has been described for simultaneous determination of Diclofenac Sodium and Misoprostol in formulation. This method is based on HPLC separation of the two drugs on the Thermo Hypersil BDS–C18 (250 mm × 4.6 mm, 5.0 μ) from Germany with isocratic conditions and simple mobile phase containing acetonitrile: water (85: 15) at flow rate of 1 mL/min using UV detection at 220 nm. This method has been applied to formulation without interference of excipients of formulation. The linear regression analysis data for the calibration plots showed a good linear relationship over the concentration range of 50-100 μg/mL for Diclofenac Sodium and 0.2-0.4 μg/mL for Misoprostol respectively. The mean values of the correlation coefficient, slope and intercept were 0.9952 ± 1.27, 80433 ± 1.18 and 187960 ± 1.82 for Diclofenac Sodium and 0.9975 ± 0.78, 862734 ± 1.21 and 4750.9 ± 1.09 for Misoprostol respectively. The method was validated for precision, robustness and recovery. The limit of detection (LOD) and limit of quantitation (LOQ) was 1 μg/mL and 2 μg/mL for Diclofenac Sodium and 0.03 μg/mL and 0.1 μg/mL Misoprostol respectively. Statistical analysis showed that the method is repeatable and selective for the estimation of Diclofenac Sodium and Misoprostol.