EXTRACTION AND QUANTIFICATION OF NICARDIPINE IN HUMAN PLASMA

A novel simple method of extraction, separation, identification and qu antification of nicardipine in human plasma samples was completely stu died. The human plasma samples were initially purified by solid-phase extraction (SPE) using a C-18 cartridge. The extracted samples were se parated and nicardipine present in the samples was quantified by high- performance liquid chromatography (HPLC) on a reversed-phase C-18 colu mn employing a mobile phase consisting of 60% (v/v) acetonitrile in 0. 02 M NaH2PO4 with pH of 6.3 and a variable wavelength UV detector set at 254 nm. The recovery of nicardipine from plasma samples using selec tive SPE was 91+/-6.0% and had less interfering compounds in the HPLC analysis compared to the use of liquid-liquid (L/L) extraction. In the HPLC analysis, examining the effect of pH values of the mobile phase on the capacity factor (k') of nicardipine revealed a method for selec ting a critical k' value of nicardipine to eliminate interfering peaks near the peak specific to the analyte. This method for quantification of nicardipine in human plasma samples was suitable for studying the pharmacokinetic profile of nicardipine administered as an intravenous bolus to cardiac surgical patients. (C) 1998 Elsevier Science B.V. All rights reserved.