Determination of domperidone in human plasma using high performance liquid chromatography with fluorescence detection for clinical application

A simple and reliable method for the determination of domperidone in human plasma has been developed. Plasma samples (1 mL) were pre-purified by a solid-phase extraction with Bond Elut® C18. The separation was achieved with XBridge™ C18 column (150 mm × 4.6 mm i.d., 5 μm) at 40 °C. The mobile phase was a mixture of acetonitrile and 10 mM ammonium acetate buffer (36:64, v/v), adjusted to pH 9.4 with 20% ammonium solution at a flow rate of 1.0 mL/min. The peak was detected using fluorescence detector at excitation 282 nm and emission 328 nm. Retention times for domperidone and internal standard (propranolol) were 8.3 min and 11.2 min, respectively. The method showed a good linearity (r > 0.999), precision (relative standard deviations <10.6%), and extraction recovery (85.7–99.7%) over a concentration of 1–100 ng/mL. The lower limit of quantification (LLOQ) was 1.0 ng/mL. This proposed method was successfully applied to a pharmacokinetic interaction study of domperidone in healthy Japanese volunteers.