HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC ULTRAVIOLET ASSAY FOR THE SIMULTANEOUS QUANTITATION OF BMS-181101 AND ITS PUTATIVE HYDROXY METABOLITES IN RAT AND MONKEY PLASMA

A specific, accurate, precise, and reproducible High-performance liqui d chromatographic-ultraviolet (HPLC-UV) method was developed for the s imultaneous quantitation of BMS-181101 (I), a new antidepressant, and its putative metabolites, 6'-hydroxy (II) and 7'-hydroxy (III) of BMS- 181101 in rat and monkey plasma, The assay procedure involved solid-ph ase extraction of the three analytes and the internal standard (IS; BM Y-42568) on 1 mi Bond Elut(R) CN cartridge using an automated solid ph ase extraction controller (ASPEC)TM system. The final elution of the a nalytes was performed using 0.25% triethylamine in methanol, The eluat e mixture was evaporated to dryness, the residue was reconstituted in the mobile phase and injected onto a Zorbax Phenyl column (4.6x250 mm; 5 mu m) at a flow-rate of 1.2 mL/min, The mobile phase consisted of 2 0% acetonitrile, 10% methanol, 69% water and 1% 1.0 M ammonium phospha te and 1.0 M tetramethylammonium hydroxide mixture adjusted to pH 3 by phosphoric acid, An ultraviolet absorbance detector set at 287 nm was used to detect the analytes, The nominal retention times were 5, 8, 1 5, and 18 min for II, III, I, and IS, respectively, The standard curve s for the three analytes were linear in the concentration range of 50- 1000 ng/mL. The lower limit of quantitation was 50 ng/mL for each anal yte, The analyses of quality control (QC) samples indicated that the n ominal values could be predicted with an accuracy of (+/-) 10.5% for a ll three analytes in rat and monkey plasma, The precision values of th e QC samples for all three analytes were within 12.7% RSD for rat and monkey plasma, All three analytes and the IS were stable in the autosa mpler for at least 38 h; freeze/thaw stability of the 3 analytes was e stablished for three cycles, Stability of BMS-181101 was established f or one month at - 20 degrees C. The application of the assay to a phar macokinetic study in monkey is described.