M.Akiful Haque,

www.ijipsr.com The present study describes the development of a new, simple, reproducible RP-HPLC method for the estimation of Oseltamivir phosphate (OSP) in bulk form. The proposed method utilizes Water’s X Bridge 5μ C18 (250mmX4.6mm)with isocratic run using 0.680 ml of Tri ethyl amine is dissolved in 500ml of HPLC grade water aqueous solution and 40volume of methanol. The pH of the resulting solution was adjusted to10.04±0.1by using conc. HClat a flow rate of 0.9ml/min. and UV detection at 226 nm. The method was statistically validated for linearity, ruggedness, robustness, precision, and accuracy. The calibration curve was obtained in the concentration range of 2.5ng/ml to 15ng/ml with correlation coefficient 0.998. The robustness of the method has been studied by slightly varying the chromatographic conditions. The ruggedness of the method was determined by carrying out the experiments on two different instruments like ShimadzuProminence and Agillent-1120. It was observed that there were no marked changes in the chromatograms; this shows the developed method is rugged and robust. The precision of the method was determined by inter-day and intraday variation studie