Enantiomer separation of basic drugs by capillary electrophoresis using ionic and neutral polysaccharides as chiral selectors.

The enantiomer separation of basic drugs by capillary electrophoresis was investigated employing two types of polysaccharides as chiral selectors. One type consists of electrically neutral polysaccharides such as dextran and dextrin, in which the separation mode is capillary zone electrophoresis (CZE), and ionic drugs are suitable for this mode. The other consists of ionic polysaccharides such as chondroitin sulfate C. Chondroitin sulfates are known as mucopolysaccharides and natural components, being charged, linear, sulfated polysaccharides of high mass. Therefore, the latter approach can be classified as affinity electrokinetic chromatography (AEKC). Both ionic and neutral drugs can be separated by AEKC owing to its separation principle. The separation of enantiomers of some basic drugs such as diltiazem and trimetoquinol was investigated with both CZE and AEKC employing polysaccharides as mentioned above and the enantioselectivity was compared. A brief mechanism of enantiorecognition by polysaccharides is also described.