| Cyclodextrins (CDs) are cyclic oligosaccharides formed a-D-glucopyranosyl units which are linked together via a series of a(1,4)-glycosidic linkages. The most common three members are called a, b and g-CDs which are formed with 6, 7 and 8 glucose unit respectively. All three molecules have a truncated cone-shaped geometry with all the primary hydroxyl groups present at the narrower end and all the secondary hydroxyl groups at the wider end. All the macrocyclic molecules possess a cavity with diameter of ~9 to 12 A at the narrow end and height of 7.9 Å. Because the cavities are relatively hydrophobic, all CDs can be used to form inclusion complexes with organic compounds in polar solvents such as water.