RAPID DETERMINATION OF OSELTAMIVIR PHOSPHATE IN PHARMACEUTICAL PREPARATION USING MONOLITHIC SILICA HPLC COLUMN

A simple, selective, linear, accurate, and precise HPLC method using a monolithic silica column was developed and validated for rapid assay to the quality control of Oseltamivir phosphate in capsules. Isocratic elution at a flow rate of 3 mL · min−1 was employed on column Chromolith reversed phase 18e (100 *4.6 mm, Merck) at ambient temperature. Different mobile phases were tested. Optimal conditions were determined by measuring the variation of classical chromatographic parameters (retention time, plate number, and tailing factor) of Oseltamivir phosphate. The mobile phase selected consisted of formate buffer (100 mM, pH = 4) and acetonitrile; 80:20, v/v. Detection was carried out using a photodiode array detector operating at 220 nm. The method was successfully applied to a commercial pharmaceutical version. The proposed method could be applicable for routine analysis of Oseltamivir phosphate.