[Fast drug analysis by capillary electrophoresis. II. Analysis of denopamine tablets. Effects of purity of dimethyl beta-cyclodextrin as chiral selector on enantiomer separations].

Capillary electrophoresis (CE) has been utilized as a tool for enantiomeric separation. It has been incorporated into both USP and EP forums as the methods for general tests and assays. In the present study, we applied CE to the assay and content uniformity of denopamine tablets (KALGUT), which are clinically used as a cardiotonic agent. The electrophoretic solution consisted of phosphate buffer of pH 2.5 containing 2,6-di-O-methyl-beta-cyclodextrin (DM-beta-CD) to achieve enantiomer separation, because denopamine is an optically active drug. During this study, we found that the purity of the positional isomerism of DM-beta-CD, significantly influenced the resolution of denopamine enantiomers. This effect of isomer purity was also confirmed by matrix-assisted laser desorption ionization time-of-flight mass spectrometer analysis. The results of the assay and system suitability test indicated that CE method could be useful as an alternative to the conventional HPLC method.1