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.