ONLINE TRACE ENRICHMENT OF MIFENTIDINE IN PLASMA USING COLUMN-SWITCHING HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

The purpose of this study was to develop for the determination of mifentidine, a new long-acting histamine H-2 receptor antagonist,in plasma using a column-switching HPLC with a ultraviolet (UV) detection. Changing the pH influenced the species equilibria of mifentidine and these were well monitored and quantitated. This method showed a excellent precision with good sensitivity and speed, and a detection limit of 10 ng/mL. The total analysis time per sample was less than 20 min and mean coefficients of variation for intra- and inter- assay were both less than 3 %. The method has been successfully applied to plasma samples from rats receiving oral administration of mifentidine.