Calix[n]arenes as goldmines for the development of chemical entities of pharmaceutical interest.

Calix[n]arenes are macrocyclic cone-shaped compounds formed from phenolic units linked by methylene groups in the ortho position. Structural features make calix[n]arenes a versatile class of molecules that are of great interest, particularly in the pharmaceutical field. The cavity-like shape gives calix[n]arenes the ability to selectively encapsulate ions or neutral molecules, which can be used to generate carrier systems capable of increasing the solubility and diffusivity of chemical species. These resulting systems can function as deliverers of bioactive guest molecules. Host-guest molecular interactions act as the cornerstone that prompts the application of calix[n]arenes in the pharmaceutical field. Understanding their interactions in host-guest complexes is essential for the development and application of new therapeutics. In the present review, the most utilized analytical techniques for characterizing calix[n]arene inclusion complexes are discussed, and an overview of the ability of a variety of calix[n]arenes to work as host molecules for the development of chemical entities of pharmaceutical interest is also presented.