Self-assembled gels formed by covalent-bond that is able to include drug

A mixture of the calix[4]arene including hydrazine and dipheniyl aldehyde at different positions formed gel in DMSO by the hydrazone reaction under acidic conditions. These organogels were transformed into hydrogels without shape change by solvent exchange. Interestingly, G' and G '' values of the hydrogels increased 80-275-fold due to the formation of a three-dimensional network structure by intermolecular hydrogen bonding interactions. Furthermore, we describes the gel containing the drug and the release of the drug in a simple manner through solvent exchange. This suggests applicability of new drug delivery system using gel.