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 me thods for general tests and assays. In the present study, we applied CE to the assay and content uniformity of denopamine tablets (KALGUT(R), which ar e clinically used as a cardiotonic agent. The electrophoretic solution cons isted of phosphate buffer of pH 2.5 containing 2,6-di-O-methyl-beta-cyclode xtrin (DM-beta-CD) to achieve enantiomer separation, because denopamine is an optically active drug. During this study, we found that the purity of th e positional isomerism of DM-beta-CD, significantly influenced the resoluti on of denopamine enantiomers. This effect of isomer purity was also confirm ed by matrix-assisted laser desorption ionization time-of-flight mass spect rometer analysis. The results of the assay and system suitability test indi cated that CE method could be useful as an alternative to the conventional HPLC method.