A rapid HPLC assay for the simultaneous determination of propafenone and its major metabolites in human serum.

A rapid and specific HPLC method has been developed and validated for the simultaneous determination of propafenone, an antiarrhythmic agent, and its major metabolites in human serum. The sample preparation was a simple deproteinization with a mixture of ZnSO4 and methanol, yielding almost 100% recoveries of three compounds. Separation was developed on a reverse-phase tracer excel C18 column (25 x 0.46 cm i.d., 5 microm), using an acetonitrile-phosphate buffer gradient at a flow rate of 1.7 ml min(-1), and UV detection of 210 nm. The calibration curves were linear (r2 > 0.999) in the concentration range of 10 - 750 ng ml(-1). The lower limit of quantification was 10 ng ml(-1) for all of the compounds studied. The within and between day precisions in the measurement of QC samples at four tested concentrations were in the range of 1.4 - 8.1% and 4.2 - 11.5% RSD, respectively. The developed procedure was applied to assess the pharmacokinetics of propafenone and its major metabolites following administration of a single 300 mg oral dose of propafenone hydrochloride to three healthy male volunteers.