STEREOSELECTIVE HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC ASSAY FOR THEDETERMINATION OF OPC-18790 ENANTIOMERS IN HUMAN PLASMA AND URINE

A high-performance liquid chromatographic assay method for the quantif ication of OPC-18790 enantiomers in human plasma and urine is describe d. A human plasma or urine was extracted with organic solvent under al kaline conditions following the addition of internal standard. The ena ntiomers and internal standard were then derivatized by reaction with the chiral reagent GITC (2,3,4,6-tetra-0-acetyl-beta-D-glucopyranosyl isothiocyanate), followed by octadecylsilica chromatographic separatio n of the diastereomeric products. The mobile phase consisted of aceton itrile-water (41:59). The fluorescence of the eluate was monitored at 355/405 nm. The lowest quantification limit of each enantiomer was 10 ng/ml in plasma and 0.1 mug/ml in urine. Both intra- and inter-day coe fficients of variation were below 10%. The assay is sensitive, specifi c and applicable for stereoselective pharmacokinetic studies in human.