Sol-gel derived silica polymers for the sustained release of proteins

The use of wet silica based polymers obtained by the sol-gel technology for the entrapment and sustained release of macromolecular bioactive compounds and, more specifically, proteins with pharmaceutical applications, is disclosed. The wet-gel formulations are obtained by a method which comprises mixing an alkoxysilane solution, a gelling catalyst and a buffered water solution of a biologically active principle and subsequently casting the thus-obtained mixture into suitable containers without previous or subsequent partial or complete removal of the water solvent; the containers are then sealed after casting in order to preserve the wet state of the gel. The wet-gel formulations may then be used for the manufacture of a ready-to-use injectable solution by mixing the silica wet-gel formulation with water or with a physiological water solution.