(Cyclodextrins)

Cyclodextrins, Cyclic oligosaccharides , were discovered approximately 100  years ago. In the pharmaceutical industry , Cyclodextrins have mainly been used  as complexing agents to increase the aqueous solubility of poorly water-soluble drugs , and to increase their bio- availablity and stability . In addition, Cyclodextrins can be used to reduce or prevent gastro-intestinal (GI) or ocular irritation, reduce or eliminate unpleasant smells or tastes ,  prevent drug-drug  or drug-additive  interactions, or even to convert oils & liquid drugs into micro-crystalline or amorphous powders. The ability of Cyclodextrins to form complexes with a wide variety of organic compounds , helps to alter the apparent solubility of the molecule, to increase the stability of compound in the presence of light , heat and oxidizing conditions and to decrease volatility of compound. Cyclodextrins can also be used as processing aids to isolate compound from natural sources and to remove unwanted compounds such as cholesterol from food products.

Cyclodextrins can be used as process aids to remove specific components from a mixture or minerals. The components which have been removed may either be discarded or further purified and the Cyclodextrin recycled. Heat method, High pH method, or solvent method can be used for the separation. Cyclodextrins are capable of forming of inclusion complexes.
Cyclodextrins are produced by a highly selective enzymatic synthesis consisting of Six, Seven, or Eight glucose monomers averaged in a donut shaped ring, which are denoted alpha, beta or gamma Cyclodextrin respectively. The specific coupling of the glucose monomers gives the Cyclodextrin a rigid  conical molecular structure with a hollow interior of a specific volume.
This internal cavity, which is hydrophobic in its nature, is a key structural feature of the Cyclodextrins, providing the ability to complex and contain a variety of “guest” molecules (e.g. aromatic, alcohol, halides and hydrogen halides, fatty acids and other esters etc.).  The guests must satisfy the size criterion of fitting at least partially into the Cyclodextrin internal cavity, resulting in an inclusion complex. The Empirical  Formula is (C6H10O5)7 and is basically a carbohydrate.