Separation of enantiomers of drugs by capillary electrophoresis with permethyl-gamma-cyclodextrin as chiral solvating agent

High-throughput screening is a promising new approach in analytical chemist ry. Within the framework of an extended screening program (The German-Chine se Drug Screening Program), the enantioseparation of 86 drugs was investiga ted by capillary zone electrophoresis in the presence of the chiral solvati ng agent (CSA) octakis-(2,3,6-tri-O-methyl)-gamma-cyclodextrin (TM-gamma-CD ). By this means, 15 drugs could be separated into enantiomeric pairs. Appr oximate measures for the degree of interaction (migration retardation facto r, R-m) and for the degree of enantiomer recognition (migration separation factors, alpha(m)) revealed intriguing patterns that were compared with tho se found for native gamma-cyclodextrin (gamma-CD). Although there is a dist inct influence of the analyte structure on the electrophoretic data, interp retation remains difficult. Most remarkably, permethylation of gamma-CD lea ds neither to a higher affinity nor to better chiral recognition, in contra st to the findings with alpha-CD.