Advances in physical chemistry and pharmaceutical applications of cyclodextrins

Cyclodextrins (CDs) attract much attention for industrial applications and aca- demic research. A few experimental methods for determination of the binding constant be- tween CD and a guest molecule were reviewed critically. A hydrophile-hydrophobe match- ing model for host-guest docking was proposed for estimation of the binding constant and the solution structure of the complex. Rather detailed solution structures of CD complexes were determined by proton NMR spectroscopy, aided by calculations of molecular mechan- ics and surface areas, and were used to analyze the binding constants. The binding constants of CDs with multi-site guests were analyzed on the basis of their solution structures. The working mechanisms and physicochemical predictions in a few pharmaceutical applications of CDs were proposed on the basis of detailed solution structures and accurate binding con- stants.