Cyclodextrins and their Derivatives as Carrier Molecules in Drug and Gene Delivery Systems

Cyclodextrins (CDs) are naturally occurring cyclic oligosaccharides containing six (α-CD), seven (β-CD), eight (γ-CD) and more glucopyranose units linked with α-(1,4) bonds, having a terminal hydrophilic part and central lipophilic cavity. α-, β- and γ-CDs are widely used in many industrial products, technologies and analytical methods owing to their unique, versatile and tunable characteristics. In the pharmaceutical industry, CDs are used as complexing agents to enhance aqueous solubility, physico-chemical stability and bio-availability of administered drugs. Herein, special attention is given to the use of α-, β- and γ-CDs and their derivatives in different areas of drug and gene delivery systems in the past few decades through various routes of administration with a major emphasis on the more recent developments.