An in vitro controlled release study of valproic acid encapsulated in a titania ceramic matrix

M.J. Uddin1,2,3, D. Mondal4, C.A. Morris3, T. Lopez1,5,6, U. Diebold2 and R.D. Gonzalez1

1 Department of Chemical and Biomolecular Engineering, Tulane University, New Orleans, LA 70118, USA
2 Department of Physics and Engineering Physics, Tulane University, New Orleans, LA 70118, USA
3 Department of Microbiology and Immunology, Tulane University, New Orleans, LA 70112, USA
4 Department of Pharmacology, Tulane University, New Orleans, LA 70112, USA
5 Nanotechnology Laboratory, National Institute of Neurology and Surgery, Mexico DF 14279, Mexico
6Universidad Autonoma Metropolitana-Xochimilco, Health Department, Mexico, DF 04960, Mexico

Appl. Surf. Sci. 257 (2011) 7920-7927

Despite the therapeutic efficacy of valproic acid towards numerous diseases, its poor bioavailability and systemic side effects pose significant barriers to long term treatment. In order to take advantage of controlled release implants of valproic acid, the drug was encapsulated into titania ceramic matrices via a sol-gel process. The integrity and structure of valproic acid-containing matrices were characterized through the use of FESEM, TEM, and BET analyses. In vitro controlled release studies and kinetic analyses were performed under ambient conditions (25 °C, atmospheric pressure) and controlled release behaviors were studied using a GC-MS method. Results showed first order dependence in the rate of valproic acid release as a function of drug concentrations in the titania ceramic device. A marked dependence on the surface area and pore size distribution with drug loading was also observed. This research opens new possibilities for the design of novel time-delayed controlled release systems for valproic acid encapsulates.

Reprints available from U. Diebold (diebold at iap_tuwien_ac_at).

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