ENANTIOMER SEPARATION OF DISOPYRAMIDE WITH CAPILLARY ELECTROPHORESIS USING VARIOUS CYCLODEXTRINS

Enantiomers of disopyramide display different biological actions, and therefore chiral selective analysis is necessary. Fifteen different cy clodextrins (CDs) and CD derivatives were tested as capillary electrop horesis (CE) additives for the chiral separation of disopyramide. Elev en types of CDs showed chiral recognition features and four types had a baseline or close to baseline separation. The best resolution (R-s = 3.0) was with 15 mM carboxymethylated beta-CD (pH 4.9). A sharp decre ase in the selectivity of gamma-phosphate (gamma-PhoCD) was observed i n the pH range of 2-3, indicating a structural change of gamma-PhoCD. The enantiomers of disopyramide were separated in its ionized as well as neutral forms using acidic substituted CDs. The results show that t he size of the CD cavity can not be used as a guide to estimate chiral separations, suggesting a more complex separation mechanism of these CDs towards disopyramide.