Simultaneous determination of the peptide-mitomycin KW-2149 and its metabolites in plasma by high-performance liquid chromatography

A gradient high-performance liquid chromatographic (HPLC) method is describ ed for the quantification of KW-2149 and its two major metabolites in plasm a. The method involves a sample clean-up by solid-phase extraction on C-18 columns, separation of the respective compounds by HPLC on a YMC ODS-AQ col umn (5-mu m particle size, 150x6 mm I.D.), using a methanol-water gradient system as an eluent, and measurement by UV absorbance detection at 375 nm. The limits of quantitation were 10 ng/ml for KW-2149 and M-16, and 15 ng/ml for M-18. Recoveries from plasma were higher than 92% on C-18 extraction c olumns. Intra-day precision, expressed as %C.V., was between 1.4 and 6.5%. Intra-day accuracy ranged from 94 to 107%. Precision and accuracy of variab ility of inter-assays increased somewhat; however, were still within accept able ranges. The ability of the method to quantify KW-2149 and two major me tabolites simultaneously, with precision, accuracy and sensitivity, make it useful in monitoring the fate of this new mitomycin in cancer patients. (C ) 2000 Elsevier Science B.V. All rights reserved.