Determination of drug-cyclodextrin binding constants by capillary zone electrophoresis

Binding constants of the optical isomers of Deprenyl(R) (selegiline) and its potential metabolites with (2,6-di-O-methyl)-beta-cyclodextrin were determined using electrophoretic mobility data gained from separations performed by capillary electrophoresis, and absorbancies obtained from spectrophotometric experiments. To calculate equilibrium constants 1:1 complex formation have been assumed. The comparison of the equilibrium constants calculated from different methods shows similar values in their order of magnitude. Their difference may probably be explained by the different media of the measurements. The effect of the structure of compounds on chiral discrimination were also elucidated.