DETERMINATION OF CICLETANINE IN HUMAN PLASMA BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY USING AUTOMATED COLUMN SWITCHING

The automated determination of cicletanine in human plasma by column-switching high-performance liquid chromatography with fluorescence detection is described. A linear response was observed for the plasma calibration curve in the range 0.05-10-mu-g base/ml. The minimum quantifiable level of the assay was 0.05-mu-g base/ml plasma. The extraction efficiency was approximately 98% for both cicletanine and the internal standard. Precision (coefficient of variation) ranged from 0.9 to 6.3% and the accuracy ranged from -8.5 to 5.3%. Freezing samples up to three months had no apparent effect on sample integrity. The method has been used to analyze rat and dog plasma samples from toxicology studies as well as human plasma from phase I and II clinical trials. This method has several advantages over previously published methods including reduced sample volume requirement and minimal sample preparation.