Simultaneous determination of ezetimibe and atorvastatin calcium in spiked human plasma using SPE coupled to HPLC-MS/MSAuthor(s): Yehia Z.Baghdady, Medhat A.Al-Ghobashy, Abdel-Aziz E.Abdel-Aleem, Soheir A.Weshahy
Combination drug products containing ezetimibe (EZB) and atorvastatin calcium (ATVC) are widely used for treatment of hyperlipidemia.Arapid, simple and sensitive liquid chromatographyÂtandem mass spectrometry (LC-MS/MS)method for determination of EZB andATVC in spiked human plasma has been developed and validated.Plasma samples were subjected to solid phase extraction before analysis with an extraction recovery of 90.59 - 98.02%. Chromatographic separation was performed on a C18 column using isocratic elutionwithin 2 min run time. The mobile phase consisted of acetonitrile: 1%of formic acid inwater (8: 2, v/v) and was pumped at a flow rate of 0.8 mL/min. Detection of analytes was achieved by with electrospray ionization (ESI) in negative ionmode for EZB and positive ion mode forATVC. The calibration curves were linear over the range of 1.67 Â 83.33 ng/mL for both drugs. The precision at the lower limit of quantitation for EZB (12.97%) andATVC (8.99%) was determined. The intra- and interday precisionswere within 9.16%, while the accuracy ranged from94.18 to 106.94%. The validated LC-MS/MSmethod was successfully employed for thedetermination of EZB andATVC in spiked human plasma for application in therapeutic drugmonitoring.