Development and Validation of a Bioanalytical Method for the Quantification of Clopidogrel in Human Plasma by LC-MS/MS using the Accuracy Profiles

A basic bio-analytical method using liquid chromatography-tandem mass spectrometry (LC-MS/MS) has been developed for the determination of clopidogrel in human plasma. Clopidogrel-d3 was used as an internal standard (IS). Protein precipitation with acetonitrile for extraction of clopidogrel and it IS was used. Chromatographic separation of clopidogrel and IS was performed on a Synergi reverse phase C18 column (150 mm x 2 mm, 4 mu m) using an isocratic mode. The mobile phase contained a mixture of 0.1% formic acid and acetonitrile (25 : 75) applying a flow rate of 0.4 mL/min. Ionization was performed by an electrospray ionization source (ESI), in positive MRM (Multiple Reaction Monitoring) mode. This method was validated by accuracy profiles approach using tolerance intervals limits. The calibration curve ranged from 0.0156 ng/mL to 8 ng/mL. This method can be employed effectively in bioequivalence and/or pharmacokinetics. In this method we have avoided the use of methanol in all steps of bioanalysis of clopidogrel to avert the back-conversion of clopidogrel metabolite.