Sensitive Quantification of Carboxylic Acid Metabolite of Clopidogrel in Human Plasma by LC with UV Detection

A rapid LC method with UV detection was developed for the quantification of carboxylic acid metabolite of clopidogrel in human plasma. Following a simple protein precipitation using a mixture of methanolic solution of ZnSO(4), the analyte and commercially available internal standard were separated using a mobile phase of water-acetonitril (85:15, v/v) adjusted to pH 3.5 on a Chromolith C18 column at a flow rate of 2.5 mL min(-1) with a total retention time of 4 min. Linearity was verified over the range of 20-3,000 ng mL(-1) where the LOQ was 20 ng mL(-1). This method was applied in a pharmacokinetic study.