High-performance liquid chromatographic analysis of the anti-tumor agent SCH 66336 in cynomolgus monkey plasma and evaluation of its chiral inversionin animals

SCH 66336 is a novel non-cytotoxic anti-tumor agent that is in phase I/II c linical trials for the treatment of solid tumors. This compound is a single enantiomer with one chiral center. Prior to evaluation of this drug candid ate in man, it was necessary to evaluate its pharmacokinetics and possible chiral inversion in animals. Thus, high-performance liquid chromatographic (HPLC) methods have been developed for its determination in cynomolgus monk ey plasma and for the evaluation of its chiral inversion in rats and cynomo lgus monkeys. The achiral HPLC analysis involved extraction with 30% methyl ene chloride in hexane followed by separation on a CN column and quantitati on by UV absorbance at 280 nm. The method was linear over a concentration r ange of 0.1 to 20 mu g/ml in monkey plasma. The chiral HPLC analysis involv ed the use of a Chiralpak AD column set at 39 degrees C with a mobile phase of hexime-ethanol-diethylamine mixture and a UV detector set at 280 nm. Pl asma samples were subjected to solid-phase extraction on a C-2 cartridge pr ior to HPLC analysis. The method was linear over a concentration range of 0 .25 to 10 mu g/ml in rat and cynomolgus monkey plasma for both enantiomers. Both methods showed good linearity (r(2)>0.99), accuracy (bias<13%) and pr ecision (CV<12%). Chiral HPLC analysis indicated that SCH 66336 was not sub jected to chiral inversion in rats and cynomolgus monkeys (C) 1999 Elsevier Science B.V. All rights reserved.