Crystal structure of the inclusion complex of beta-cyclodextrin with mefenamic acid from high-resolution synchrotron powder-diffraction data in combination with molecular-mechanics calculations
Pop MM, Goubitz K, Borodi G, Bogdan M, De Ridder DJA, Peschar R, Schenk H
ACTA CRYSTALLOGRAPHICA SECTION B-STRUCTURAL SCIENCE 58: 1036-1043 Part 6 DEC 2002

Abstract:
The crystal structure of the inclusion complex of beta-cyclodextrin with mefenamic acid has been determined from a combination of high-resolution synchrotron powder-diffraction data and molecular-mechanics calculations. A grid search indicates two possible solutions, which are corroborated by molecular-mechanics calculations, while Rietveld-refinement results suggest the crystal structure that is more likely to be formed in the solid state. Mefenamic acid is partially included in beta-cyclodextrin with either the xylyl or the benzoic-acid moiety being inside its cavity. In both solutions mefenamic acid and beta-cyclodextrin form a monomeric complex in a herringbone packing scheme.