Abstract
The application of ionic liquids（ILs）to DDS has been investigated to improve physicochemical properties and bioavailability of active pharmaceutical ingredients（APIs）as well as to overcome biological barriers, such as skin and gastrointestinal tract, that hamper drug delivery to the desired site. ILs have been utilized as a drug vehicle to achieve solubilization, stabilization, or enhancement of absorption of APIs. Another approach is converting APIs themselves to ILs, called API-ILs, by using APIs as cationic and/or anionic molecules to prepare ILs. Those approaches can be applied to various therapeutic modalities from small molecular to macromolecular drugs. In this review, we will introduce recent advances on both the use of ILs as drug vehicles and the development of API-ILs, and also summarize their usefulness for drug delivery. Finally, we will introduce our recent work on the development of API-ILs for the treatment of central nervous system diseases.
