Abstract
This paper reports a validated RP-HPLC method for the estimation of lansoprazole and naproxen in combination formulation and human plasma. The method is achieved on a phenomenex C18 column (4.6 x 250mm, 5µ i.d), using methanol: pH 7.8 buffer (70:30%, v/v), as mobile phase mixture, applying a flow rate of 1ml/min and eluents were monitored at 214 nm with an average retention time for lansoprazole and naproxen at 4.9 and 3.71 min, respectively and the linear calibration curves between the concentration range of 100-350 µg/ml for lansoprazole and 50-300 µg/ml for naproxen. The correlation coefficient was found nearer to 0.9998 for both drugs. The LOD and LOQ for lansoprazole was 4.14; 12.57 µg/ml and naproxen was 6.5; 19.72 µg/ml, respectively. The number of theoretical plates was found to be 8932 for lansoprazole and 6385 for naproxen. Ethyl acetate was used as the extraction solvent for liquid- liquid extraction of both drugs in spiked human plasma. The developed method was evidenced to be more accurate, simple, precise and rapid by statistical validation and recovery studies.
