Picogram-Level Quantification of Piribedil in Human Plasma by LC-MS/MS Method Using SCEIX QTRAP® 5500 System: Application to a Pharmacokinetic Study on Healthy Egyptian Volunteers

A high-Performance Liquid Chromatography coupled with tandem mass spectrometry (HPLC–MS/MS) was used to develop and validate a highly sensitive and rapid bioanalytical method for the analysis of piribedil in human plasma. The extraction of piribedil and the internal standard (IS) sildenafil from human plasma was done by precipitation technique with acetonitrile. The elution of the analyte and the IS was performed by a mixture of 0.01 M ammonium format (pH 3.5) and acetonitrile in ratio 60:40 ( v / v ) on a Zorbax Eclipse plus C18 (3.5 µm 100 x 4.6 mm) column. The mixture of mobile phase was pumped at a flow rate of 0.7 mL/min with a total run time of 3.3 min. Detection was done by API 5500 Q.Trap mass spectrometer in multiple reaction monitoring (MRM) mode and positive electrospray ionization interface (ESI). The detection of piribedil in plasma was measured over a concentration range of 0.02 – 5.00 ng mL -1 and all items of validation were executed according to FDA and EMA guidelines. This method was well applied for the determination of piribedil in the plasma of ten healthy subjects after administration of 50 mg oral dose and pharmacokinetic parameters were measured.