The determination of dielectric constants of mixtures used in the treatment of epilepsy and the encapsulation of phenytoin in a titania matrix

In this study it is shown that an anticonvulsant drug such as phenytoin can successfully be encapsulated in a titania matrix. Infrared studies show that as a result of the encapsulation process, the structure of phenytoin is not chemically altered. BET studies show that the surface area of phenytoin is small in comparison to the surface area obtained following adsorption of the drug onto the surface of the titania. The dielectric constants of phenytoin, valproic acid and mixtures of the two were calculated. They were found to be independent of composition. Using stereotactic surgery the phenytoin/titania reservoir was implanted in the temporal lobe of the brain of a Winstar rat. Furthermore, the implanted device was found to be biocompatible with the surrounding tissue. An immunohistochemical study showed that chemical changes did not occur in the neurons surrounding the implant. Simulation studies show how to identify the pore size distribution required for the successful encapsulation of phenytoin. The formation of electrical dipoles within the titania matrix is discussed. (C) 2006 Elsevier B.V. All rights reserved.