The pharmaceutically useful cyclodextrins (CyDs) are classified into hydrophilic, hydrophobic, and ionic derivatives. These CyDs can serve as multi-functional drug carriers, through the formation of inclusion complex or the form of CyD/drug conjugate. In addition, the combined use of different CyDs and/or pharmaceutical excipients is capable of alleviating the undesirable properties of drug molecules, improving efficacy and reducing side effects. This contribution outlines the potential use of CyDs in the design and evaluation of CyD-based drug formulation, focusing on their ability to enhance the drug absorption across biological barriers, the ability to control the rate and time profiles of drug release, and the ability to deliver a drug to targeted site.