β-Cyclodextrin (β-CD) is a cyclic oligosaccharide that contains seven D-(+)-glucopyranose units and has been used to improve the aqueous solubility of various compounds, especially those containing a phenyl group.1,2 The circular arrangement of its glucose units produces a torus-shaped ring configuration in which the CH2 groups and ether linkages of the molecule face the hollow interior, resulting in a nonpolar, hydrophobic cavity and a polar, hydrophilic exterior. When combined in solution with other compounds, the nonpolar aromatic portions of that compound interact with the nonpolar interior of the β-CD molecule, thus isolating the aromatic portion of the molecule from the water and thereby increasing its aqueous solubility.1,3
1.Katageri, A.R., and Sheikh, M.A.Cyclodextrin a gift to pharmaceutical world reviewInt. Res. J. Pharm.3(1)52-56(2012) 2.Williamson, G.B., and Weidenhamer, J.D.Bacterial degradation of juglone: Evidence against allelopathy•J. Chem. Ecol.16(5)1739-1742(1990) 3.Rao, V.M., Nerurkar, M., Pinnamaneni, S., et al.Co-solubilization of poorly soluble drugs by micellization and complexationInt. J. Pharm.319(1-2)98-106(2006)