Use of spectral mapping technique for the separation of solvent strength and selectivity on β-cyclodextrin polymer-coated HPLC column using monoamine oxidase inhibitory drugs as solutes

Spectral mapping technique has been used for the separation of the strength and selectivity of retention of 17 monoamine oxidase inhibitory drugs and 5 organic modifiers on a β-cyclodextrin polymer-coated silica column (βCDP). The potency values of the spectral maps were considered as indicators of the capacity of drugs to bind to the βCDP surface and the capacity of organic modifiers to remove the drugs from the surface. The multidimensional selectivity map were visualized by the two-dimensional nonlinear mapping technique. Stepwise regression analysis established that both the steric dimensions and hydrophobicity of drugs influence the strength and selectivity of their binding to βCDP whereas the selectivity of organic modifiers depended on the bulkiness of the molecule. The data suggest that the interaction of drugs and organic modifiers with the surface of the βCDP support depends on their capacity to fit sterically in the βCDP cavity and the strength of the hydrophobic forces between the apolar inner wall of the cyclodextrin cavity and the substructures of guest molecules inserted in the cavity.