The analysis of cyclophosphamide and its metabolites

Cyclophosphamide (CP) has been in clinical use for the treatment or maligna nt disease for over 40 years. CP is inactive until it undergoes complex met abolic pathways leading to the ultimate alkylating agent, phosphoramide mus tard, but also to inactive and toxic metabolites. Sensitive and specific me thods are now available for the measurement of CP and its enantiomers, its metabolites anti their stereoisomers, in biological matrices. An overview i s given of the methods of analysis of CP and its metabolites described in l iterature since 1993 as well as the current knowledge about its metabolism. Five classes of methods are described: (1) thin-layer chromatography-photo graphic densitometry, (2) high performance liquid chromatography, (3) gas c hromatography and gas chromatography coupled to mass spectrometry, (4) phos phorus-31 nuclear magnetic resonance and (5) enantiomeric separation. In ea ch case, sample clean up and preparation are described. Precision and limit s of quantification of the assays are indicated. A table summarizes all the analytical methods for assaying each metabolite.