LIQUID-CHROMATOGRAPHIC DETERMINATION OF TOTAL CELIPROLOL OR (S)-CELIPROLOL AND (R)-CELIPROLOL SIMULTANEOUSLY IN HUMAN PLASMA

A method has been developed for the determination of total celiprolol (sum of enantiomers) or the enantiomers (R)-celiprolol and (S)-celipro lol in plasma by high-performance liquid chromatography with UV and fl uorescence detection. After extraction from alkalinized plasma with me thyl-tert.-butyl ether and back-extraction into 0.01 M HCl (for total celiprolol determination) or after evaporation of the organic phase an d derivatisation with R(-)-1-(1-naphthyl)ethyl isocyanate (enantiomer determination), total celiprolol or its diastereomeric derivatives wer e chromatographed on a reversed-phase HPLC column with a mixture of ac etonitrile and phosphate buffer pH 3.5 (+0.05% triethylamine). Acebuto lol was used as internal standard. Linearity was obtained in the range of 5 to 2000 ng/ml for total and 2.5 to 500 ng/ml for enantiomer dete rmination. Intra-day and inter-day variation was lower than 10%. The m ethod can be applied for analysis of plasma samples obtained from pati ents treated with oral racemic celiprolol doses.