Rapid and sensitive determination of ketoprofen in micro-whole blood samples by high-performance liquid chromatography and its application in a pharmacokinetic study in rats

A new simple and sensitive method for determination of ketoprofen in micro-whole blood samples was developed, and its usefulness was demonstrated by the characterization of the oral pharmacokinetics of this drug in rats. Whole blood samples were added with perchloric acid to precipitate proteins, and supernatant was injected into the chromatographic system. Separation of compounds was achieved with a Symmetry C18 column eluted with a mixture of acetonitrile and 0.1M potassium dihydrogen phosphate solution pH 3.5 (48:52v/v) as the mobile phase at flow rate of 1.0mL/min. Detection was carried out by absorbance at 260nm. Under these conditions the method was linear in the range 0.1-15g/mL. In order to demonstrate the usefulness of this method, oral pharmacokinetics of ketoprofen after administration of 1, 3.2, and 10mg/kg was evaluated in rats. Blood samples were obtained at selected times during 24hr and successfully analyzed by the method described. It is concluded that the method is suitable for pharmacokinetic studies of ketoprofen using small volume of sample.