HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC ELECTROCHEMICAL ASSAY FOR THEQUANTITATION OF BMS-181885 IN MONKEY PLASMA

A high-performance liquid chromatographic-electrochemical assay was de veloped and validated for the quantitation of EMS-181885 (I), an anti- migraine agent, in monkey plasma. The assay involved a solid-phase ext raction of I and BMY-46317 (internal standard; I.S.) on a 1-ml cyano c artridge using the automatic solid-phase extraction cartridge (ASPEC) system. Immediately following the conditioning of the cyano column 3 m l of methanol and 2 ml of 1% glacial acetic acid), plasma (0.25 ml) wa s loaded on to the column. The column was then washed with a 3 ml of 0 .1 M ammonium acetate buffer (pH 6). The final elution of the analytes was performed using 2 ml of methanol. The eluate was then evaporated to dryness (gentle stream of nitrogen at 40 degrees C) and the residue was dissolved in the mobile phase and injected on to a YMC basic colu mn (15 cmX4.6 mm; 5 mu m particle size) at a flow-rate of 1 ml/min. A mixture of 0.1 M ammonium acetate at pH 6-acetonitrile-methanol (70:20 :10, v/v) was used as the mobile phase. Standard curves, with a lower limit of quantitation of 2 ng/ml of I were linear (r(2) greater than o r equal to 0.998; range: 2-50 ng/ml). Based on the analysis of the qua lity control (QC) samples, the assay was both accurate and precise. Th e stability of I was established following freeze-thaw cycles and stor age at or below -20 degrees C. The extraction recovery of I from monke y plasma was about 82%. The validated assay method was applied to dete rmine the pharmacokinetics of I in monkeys following a single 1 mg/kg intravenous dose. (C) 1998 Elsevier Science B.V.