Analysis and modelling of the structures of beta-cyclodextrin complexes.

A systematic computer graphics study of all available beta-cyclodextrin crystal structures has been carried out specifically to aid in the modelling and design of beta-cyclodextrin-drug complexes. The analyses show that the basic conformation of the molecule remains constant among natural, mono-substituted and partially permethylated beta-cyclodextrins, with major changes observed only in the case of full permethylation. In all the structures, however, there are no significant perturbations caused by guest molecule inclusion. On the basis of these observations models are proposed for the structures of beta-cyclodextrin-indomethacin complexes, the principal features of which are shown to be consistent with the data obtained in 1H-NMR studies.