Authors: T. Lopez, A. Hernandez-Ayala, J.A. Odriozola, P. Quintana, R.D. Gonzalez, P.P. Lottici and I. Marino
Affilation: Tulane University, United States
Pages: 398 - 401
Keywords: titania, reservoirs, valproic acid, drug delivery
In this study, sol-gel titania implants used in the controlled rate of drug release of valproic acid to the temporal lobe of the brain were optimized to insure that the correct drug dose is delivered. In previous studies we have reported that the rate of drug release to the temporal lobe of Wistar rats is dependent on (a) porosity and, (b) chemical linteractions between valproic acid and the surface hydroxyl groups of titania. When the sol-gel process is used in the synthesis, the concentration of water used in the hydrolysis reaction is an important variable in the degree of hydroxylation, porosity and structural defects in the framework of the nanostructured titanium oxide resevoir. The alcoxide /water ratio was systematically varied during the synthesis of the reservoir. Water was added in a dropwise manner during the hydrolysis of titanium n-butoxide. The valproic acid was incorporated into the framework during the synthesis. The resultant gels were dried under mild conditions over a 3 week period in order to to preserve the structure of the valproic acid. Characterization studies were performed using both TEM and BET. Kinetic studies on the rate of drug release were also performed. The particle size was found to be critically important since penetration through a sol-gel nanostructured titania device is required. These nanostructured devices will be used in the control of epilepsy.