Quantification of carvedilol in human plasma by liquid chromatography using fluorescence detection: Application in pharmacokinetic studies

A simple, rapid and sensitive isocratic reversed-phase HPLC method with fluorescence detection using a monolithic column has been developed and validated for the determination of carvedilol in human plasma. The separation was performed on a Chromolith Performance (RP-18e, 100 mm × 4.6 mm) column with an isocratic mobile phase consisting of 0.01 M disodium hydrogen phosphate buffer–acetonitrile (40:60, v/v) adjusted to pH 3.5. The sample preparation involves protein precipitation procedure and analytical recovery was complete. Letrozole was used as internal standard. The assay enables the measurement of carvedilol for therapeutic drug monitoring with a minimum quantification limit (LOQ) of 1 ng ml−1. The excitation and emission wavelengths were set at 240 and 340 nm, respectively. The calibration curve was linear over the concentration range 1–80 ng ml−1. The coefficients of variation for inter-day and intra-day assay were found to be less than 8.0%.