Enantioselective quantification of carvedilol in human plasma by HPLC in heavily medicated heart failure patients.

A simple, specific, sensitive, inexpensive and rapid HPLC method for enantioselective quantification of carvedilol in human plasma was developed in this study. S(-)- and R(+)-carvedilol and R(+)-propranolol as the internal standard were extracted from human plasma by liquid-liquid extraction using methyl tert-butyl ether. Enantioseparation was performed on a reverse-phase C18 Phenomenex Luna 5micron 150mmx2mm column after chiral derivatization with 2,3,4,6-tetra-O-acetyl-beta-d-glucopyranosyl isothiocyanate. The mobile phase was a mixture of water and acetonitrile. The peaks were detected using a fluorescence detector, where the excitation and emission wavelengths were set at 242 and 344nm, respectively. The limits of quantification for the S(-)- and R(+)-carvedilol enantiomers were both 0.5ng/ml. Combined intra- and inter-day variations for both enantiomers were less than 8.3%. The combined accuracy for both enantiomers ranged from 91.7 to 104.7%. This method was used to assay the carvedilol enantiomers in human plasma samples obtained from heavily medicated heart failure patients within the framework of a clinical trial.