Fast, simultaneous quantification of three novel cardiac drugs in human urine by MEPS-UHPLC-MS/MS for therapeutic drug monitoring

A sensitive and selective ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) method was developed for the fast, simultaneous quantification of three novel cardiac drugs (aliskiren, prasugrel and rivaroxaban) in human urine. Sample preparation was performed with microextraction with packed sorbent (MEPS), which is a miniaturization of solid phase extraction. The optimal conditions for MEPS extraction were obtained using C8 sorbent, small sample volumes and a short time period (about 3min for the entire sample preparation step). Chromatographic separation of the selected compounds was achieved in less than 1.5min on a Zorbax Rapid Resolution High Definition SB-C18 column using isocratic elution with 0.1% formic acid and acetonitrile (70:30, v/v) at a flow rate of 0.8mLmin^-1. The detection was performed on a triple quadrupole tandem mass spectrometer by multiple reaction monitoring via an electrospray ionization source with positive ionization mode. The method was fully validated according to the latest recommendations of international guidelines. The lower limit of quantification was 5.0pgmL^-1 for aliskiren and rivaroxaban and 0.5pgmL^-1 for prasugrel. The intra- and inter-day precision was within 7.12% and the accuracy ranged from -7.54% to 4.17%. The mean extraction recoveries of the MEPS_C8 methodology were found to be 98.3% for aliskiren, 100.3% for rivaroxaban and 99.9% for prasugrel. This MEPS_C8-UHPLC-MS/MS method offers a fast, simple and precise way to determine selected novel cardiac drugs in human urine that could be applied to therapeutic drug monitoring and pharmacokinetic studies.