Complex and mixture of β-cyclodextrin with diazepam characterised by ¹H NMR and atom-atom potential methods.

Inclusion complex of β-cyclodextrin with diazepam and a physical mixture of these components were studied by solid-state (1)H NMR. The activation barrier for reorientation of the methyl group in the diazepam molecule was found not changed by complex formation with β-cyclodextrin. The complex formation resulted in a decrease in the number of water molecules and affected the relaxation time of β-cyclodextrin. By the atom-atom potential method the most probable configuration of the diazepam molecule inside β-cyclodextrin cavity was proposed.