AUTOMATED-DETERMINATION OF A NOVEL ANTIINFLAMMATORY DRUG IN PLASMA USING BATCH ROBOTIC SAMPLE PREPARATION AND HPLC

A Zymark XP Robot has been adapted to extract a novel anti-inflammator y drug (CI-1004) and internal standard (IS) from rat plasma using a ba tch robotic solid-phase extraction system. Under computer control, the robot automatically conditions, loads, washes, and elutes up to 144 s olid-phase cartridges in parallel. The system incorporates a miniature pressure transducer to monitor and control manifold vacuum, thereby c ontrolling solvent flow through the cartridges. Liquid chromatographic separation was achieved isocratically on a Zorbax Rx-C8 analytical co lumn (4.6 mm i.d. x 250 mm). Mobile phase consisted of 65:35 (v/v) ace tonitrile and 20 mM ammonium acetate (pH = 4.0). Column effluent was m onitored spectrophotometrically at 360 nm. Specificity, chromatographi c performance parameters, system repeatability, recovery from matrix, linearity, precision, and accuracy were evaluated. No interfering peak s were observed at the retention time of CI-1004 throughout the valida tion process. Peak-height ratios were proportional to CI-1004 in rat p lasma over the concentration range of 7.5-5000 ng/mL. The system is ca pable of extracting 100 plasma samples in approximately 5 hours. (C) 1 996 John Wiley & Sons, Inc.