HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC ANALYSIS OF KEBUZONE AND ITS METABOLITES IN THE SAMPLES OF ERYTHROCYTES, PLASMA, AND WHOLE-BLOOD

Within the framework of behaviour study of non-steroidal anti-inflammatory drugs of different structural types kebuzone was analysed as a representative of the 3,5-pyrazolidinedione group. High-performance liquid chromatographic method has been developed to determine kebuzone and its three metabolites in erythrocytes, plasma and whole blood samples. Isolation of kebuzone from these samples has been optimized with respect to transformation of kebuzone. Samples of erythrocytes, plasma and whole blood were deproteinated, but before this adjustment it was necessary to carry out haemolysis of erythrocytes. The supernatant was chromatographed on a glass column of SGX C-18 (150mm x 3.3mm LD.) using methanol and water with final apparent pH 2.7 as the mobile phase pumped at a now-rate of 0.5 ml/min and ultraviolet detection at 247 nm. The method employs an internal standard resulting in good accuracy and precision. The method has been successfully applied to a 2-h pharmacokinetic study of kebuzone in rabbits.