Recent advances in cyclodextrin delivery techniques.

INTRODUCTION: Active pharmaceutical ingredients (APIs) are evolving from low-molecular-weight drugs to peptide-, protein-, gene-, oligonucleotide- and cell-based drugs. Therefore, advanced pharmaceutical technologies are required to achieve manifestation of the drug efficacy, side effect reduction and the adequate dosage form design. AREAS COVERED: In this review, the authors highlight the recent advances in drug delivery techniques utilizing cyclodextrins (CyDs), and cyclic oligosaccharides consisting of α-1,4-linked α-D-glucopyranose units, for various drugs described above. Especially, drug delivery system consisting of combination systems of CyDs and functional materials such as dendrimer, liposome and PEG are introduced. Furthermore, the utilities of CyDs as APIs have been also described. EXPERT OPINION: To achieve the controlled release and/or targeting of low-molecular-weight drugs in systemic administration, the construction of novel CyDs and CyD the supramolecular system should be a useful approach because of the stable complexation of drugs with CyDs. In addition, the combination systems of CyDs and various carriers have the potential as advanced drug delivery systems for proteins and nucleic acids. Furthermore, CyDs have great potential as APIs for various diseases with few side effects, although the detailed mechanism, especially cellular uptake of CyDs, should be clarified.