Rapid high-performance liquid chromatographic method for determination of adefovir in plasma using UV detection: application to pharmacokinetic studies

Abstract

A rapid, sensitive and reproducible HPLC method was developed and validated for the analysis of adefovir (CAS 106941-25-7) in human plasma. The separation was achieved on a monolithic silica column (Chromolith Performance RP-18e, 10064.6 mm) using acetonitrile-ammoniumdihydrogen phosphate buffer (6: 94, v/v), pH 5.2, as the mobile phase at a flow rate of 1.5 ml min?1. The wavelength was set at 260 nm. The assay enables the measurement of adefovir for therapeutic drug monitoring with a minimum quantification limit of 1 ng ml?1. The method involves a simple protein precipitation procedure. Analytical recovery was complete. The calibration curve was linear over the concentration range 1?40 ng ml?1. The coefficients of variation for inter-day and intra-day assay were found to be less than 5%. The method was applied to the determination of adefovir in plasma from 12 subjects dosed with adefovir 2610 mg tablets and pharmacokinetic parameters were evaluated.