β-Cyclodextrin and Its Derivatives Based Drug Delivery

Cyclodextrins were first described by Villiers in 1891. Schrodinger laid the foundation of the cyclodextrin chemistry in 1903 - 1911 and identified both a and β cyclodextrin. In the 1930 s, Freudenberg identified γ-cyclodextrin and suggested that larger cyclodextrins could exist. Cyclodextrins are cyclic oligosaccharides which have recently been recognized as useful pharmaceutical excipients. The molecular structure of these glucose derivatives, which approximates a truncated cone or torus, generates a hydrophilic exterior surface and a nonpolar cavity interior. As such, cyclodextrins can interact with appropriately sized molecules to result in the formation of inclusion complexes. These non covalent complexes offer a variety of physico-chemical advantages over the unmanipulated drugs including the possibility for increased water solubility and solution stability. The purpose of this review is to discuss and summarize some of the interesting findings and applications of β-cyclodextrins and its derivatives in different areas of drug delivery, particularly in protein and peptide drug delivery and gene delivery. The article highlights important cyclodextrin applications in the design of various novel delivery systems like liposome's, microspheres and nanoparticles.