Capillary electrophoresis coupled with microdialysis for continuous monitoring of free metoprolol in rabbit blood

A microdialysis method followed by a capillary electrophoresis (CE) procedure has been performed for the determination of metoprolol in rabbit blood. A microdialysis probe was inserted into the ear vein for blood sampling. The electrophoresis conditions were: 47 (40) cm x 50 mu m silica capillary, 50 mM acetate buffer solution (pH 4.0), 10 s hydrodynamic load, detection wavelength 214 nm, run voltage 18 kV, temperature 25A degrees C. The calibration was linear within the range of 1.0-100 mu g/mL (r > 0.999). The limit of detection (LOD) was 0.5 mu g/mL. Intra-day and inter-day repeatabilities with relative standard deviations (RSDs) a parts per thousand currency sign 5.1% were obtained. The method was then applied to pharmacokinetics profiling of metoprolol in the blood following oral administration of metoprolol to rabbits.