Role of mesoporous silicates on carbamazepine dissolution rate enhancement

Carbamazepine is an antiepileptic drug characterized by poorly water solubility that affects negatively its bioavailability. Here we report oil the ability of the mesoporous silicate MCM-41 to act as a vehicle able to improve the drug dissolution rate by preventing drug crystallization. Carbamazepine was adsorbed into nanopores of MCM-41 and the drug, loaded MCM-41 was characterized by X-ray powder diffraction, N-2 adsorption, FT-IR spectroscopy and thermogravimetric and differential scanning calorimetry analyses. Carbamazepine loading resulted 14% and the drug was not arranged in crystalline form. In vitro drug release results showed a remarkable increase of carbamazepine dissolution rate in all the different tested media. As this improvement is due both to the high specific surface area of loaded MCM-41 and to the lack of crystalline drug, storage stability studies at different environment conditions were conducted in order to investigate the ability of MCM-41 to prevent drug crystallization. (C) 2007 Elsevier Inc. All rights reserved.