Determination and pharmacokinetic study of kaempferide in rat plasma by UPLC

In this study, a simple, sensitive, and robust analytical method based on ultra-performance liquid chromatography (UPLC) has been developed for the determination of kaempferide in rat plasma using diazepam as the internal standard (IS). After sample preparation by a simple liquid-liquid extraction, chromatography was performed on an Acquity UPLC BEH C18 column (2.1 mm x 50 mm, 1.7 mm particle size) and ultraviolet detection was set at a wavelength of 366 nm. The analysis was achieved with a mobile phase of solvent A (water) : solvent B (acetonitrile) : solvent C (0.1% trifluoroacetic acid) = 35 : 45 : 20. The flow rate was 0.30 mL min(-1) and total run time was 2.0 minutes. The method was linear over the concentration range of 25-1000 ng mL(-1) with a lower limit of quantification (LLOQ) of 25 ng mL(-1). Inter- and intra-day precisions (RSD%) were all within 10.2% and the accuracy (RE%) was equal to or lower than 9.3%. Recoveries of kaempferide and IS were more than 78.4%. Stability studies showed that kaempferide was stable under a variety of storage conditions. The method was successfully applied to a pharmacokinetic study, involving the intravenous administration of kaempferide to rats.