Structural elucidation of chemically modified cyclodextrins and their inclusion complexes for medicine applications

Structural properties of selected derivatised cyclodextrins (CDs), gleaned from single crystal X-ray studies, are described with reference to the effects on molecular conformation and inclusion ability accompanying their formation from the corresponding native CDs. Species of interest include several acylated and methylated CDs as well as their inclusion complexes with drug guest molecules. As a representative example of an inclusion complex in this category for which full structural and thermal characterization has recently been achieved, that between permethylated α-CD and the antihypertensive metoprolol is presented. This inclusion complex has 2:1 host-guest stoichiometry that features novel 'bimodal' guest inclusion.