Ionic Liquids in Drug Delivery

Abstract

Ionic liquids (ILs) are molten salts composed of a large organic cation and an organic/inorganic anion. Due to their ionic character, most ILs present advantageous properties over conventional solvents, such as negligible volatility at atmospheric conditions and high thermal and chemical stabilities. The wide variety of IL anion–cation combinations allows these solvents to be designed to display a strong solvation ability for a myriad of active pharmaceutical ingredients (APIs) and (bio)polymers. Given these properties, ILs have been used as solvents and as formulation components in different areas of drug delivery, as well as novel liquid forms of APIs (API-ILs) applied in different stages of development of novel drug delivery systems. Furthermore, their combination with polymers and biopolymers has enabled the design of drug delivery systems for new therapeutic routes of administration.