Determination of Donepezil in Human Plasma by HPLC-ESI-MS

OBJECTIVE To establish an HPLC-MS method for the determination of donepezil in human plasma. METHODS Alkalized plasma was extracted with ethyl acetate and chlorphenamine maleate was used as internal standard. Solutes were separated on a Shim-pack ODS C18 column(250 mm×2.0 mm, 5 μm)with a mobile phase of methanol-0.1%acetate buffer (60∶40). The flow rate was 0.2 mL·min-1 and column was used with temperature of 35 ℃. Donepezil and internal standard were ionized in the eletrospray ionization (ESI) with positive source of the mass spectrometer and detected in selected ionization monitor (SIM) mode. RESULTS The calibration curve was linear in the range of 0.1-16.0 ng·mL-1(r=0.999 8) with the lower limit of quantitation, accuracy was within 92.5%-105.3%. The recovery of the extraction was more than 75%, intra- and inter-batch precision (RSD) were less than 10%. CONCLUSION The method is proved to be suitable for pharmacokinetics and determination of donepezil in human plasma with simple, quickness, sensitive and specificity.