An implantable sol–gel derived titania–silica carrier system for the controlled release of anticonvulsants

A sol–gel derived titania–silica reservoir has been synthesized and characterized. These materials can be used as an implantable carrier for controlled anticonvulsant delivery (sodium phenytoine and valproic acid). Xerogel characteristics, biocompatibility and in vitro release properties were obtained. FT-IR and UV–Vis spectroscopy were used to obtain information regarding the interaction between anticonvulsants and the mesoporous titania–silica ceramic. For the in vitro biocompatibility study, titania–silica reservoirs were surgically implanted into the basolateral amygdale of a rat. Following an implantation for a period of 8 months, the structure of the brain parenchyma and reservoir interface appears to be preserved. There was no evidence of inflammation or gross tissue reaction. Phenytoine was slowly released in vitro from the binary TiO2–SiO2 xerogel over a period of 500 h. We envision that this sol–gel derived titania–silica system might play a significant role in the development of a new generation of controlled release biomaterials.