Rapid determination of the anti-cancer drug chlorambucil (Leukeran (TM)) and its phenyl acetic acid mustard metabolite in human serum and plasma by automated solid-phase extraction and liquid chromatography-tandem mass spectrometry

A bioanalytical method for the determination of the anticancer drug chloram bucil (Leukeran(TM)) and its phenyl acetic acid mustard metabolite in human serum and plasma is described. Automated solid-phase extraction of the ana lytes is carried out with C-18 sorbent packed in a 96 well format microtitr e plate using a robotic sample processor. The extracts are analysed by isoc ratic reversed-phase liquid chromatography using pneumatically and thermall y assisted electrospray ionisation (TurboIonspray) with selected reaction m onitoring. The method is specific and sensitive, with a range of 4-800 ng/m l in human serum and plasma for both parent drug and metabolite (sample vol ume 200 mu l). The method is accurate and precise with intra-assay and inte r-assay precision (C.V.) of <15% and bias <15% for both analytes. The autom ated extraction procedure is significantly faster than manual sample pre-tr eatment methods, a batch of 96 samples is extracted in 50 min allowing for faster sample turnaround. The method has been used to provide pharmacokinet ic support to biocomparability studies of Leukeran(TM) following single dos es of oral tablet formulations. (C) 1999 Elsevier Science B.V. All rights r eserved.