HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC DETERMINATION OF RANITIDINE IN HUMAN PLASMA

A rapid reversed phase HPLC method for determination of ranitidine in human plasma has been developed. The procedure involved extraction of the drug from alkalinized plasma spiked with the internal standard (procainamide) using 4% v/v isopropanol in ethylacetate. The extract was evaporated under nitrogen and the residue was reconstituted with methanol and injected onto U-Bondapak C-18 column. The mobile phase is 8% v/v acetonitrile in 10 mM potassium phosphate buffer (pH 5.1); at a flow rate of 2.5 ml/min and UV detection at 330 nm. The efficiency of extraction was 90% with a detection limit of 20 ng/ml. The within-day coefficient of variations ranged from 4.09% to 5.81%, whereas those of between-day were from 7.5% to 9.51%.