Determination of glufosfamide in rat plasma by liquid chromatography/tandem mass spectrometry

A sensitive and selective high-performance analytical method based on liquid chromatography with tandem mass spectrometric detection (LC/MS/MS) was developed for the quantification of glufosfamide in rat plasma. Zidovudine was employed as internal standard. Glufosfamide was determined after methanol-mediated plasma protein precipitation using LC/MS/MS with an electrospray ionization interface in negative ion mode. Two sets of standard curves were developed, from 0.005 to 1.0 microg/mL and from 1.0 to 50.0 microg/mL. The assay was accurate (% deviations from nominal concentrations < 5%), precise and reproducible (intra- and inter-day coefficients of variation < 10%). Glufosfamide in rat plasma was stable over three freeze/thaw cycles, and at ambient temperatures, for at least 2 h. The validated method was successfully applied to the determination of glufosfamide plasma concentrations in rats for 24 h following an intravenous administration of 25 mg/kg.