Liquid chromatographic determination of cimetidine in whole blood and plasma by using short polymeric reverse phase...

A rapid and simple reverse phase liquid chromatographic method for the separation and quantitation of the H2-receptor antagonist drug cimetidine in human whole blood and plasma is described. The method involves a single step organic extraction of the drug from alkalinized biological samples followed by a salting-out of the organic solvent by an appropriate salt. A short column packed with polymeric reverse phase particles was used with an isocratic elution of 20mM potassium phosphate (pH = 9.5) and acetonitrile (87.5 + 12.5). The cimetidine was monitored at 210 nm and 0.10-0.005 absorbance unit full scale (AUFS). The relative standard deviation (%) for analysis was reproducible within 1 day and that for day-to-day analysis was 5 (n = 8) or lower.