Tablet preformulations of indomethacin-loaded mesoporous silicon microparticles

In this study, indomethacin-loaded thermally oxidized mesoporous silicon microparticles (TOPSi-IMC) were formulated into tablets with excipients in order to improve the dissolution and permeability properties of the poorly soluble drug. Formulations of TOPSi-IMC particles and excipients were prepared at different TOPSi-IMC particle ratios (25, 30 and 35%). The formulations were compressed by direct compression technique with a single punch tablet machine. For comparison, a formulation containing the bulk IMC (indomethacin) and the same excipients without thermally oxidized mesoporous silicon microparticles particles (TOPSi) was prepared and compressed into tablets. The TOPSi-IMC tablets were characterised according to weight, thickness, crushing strength, disintegration time and dissolution rate. The results of this study show that TOPSi-IMC particles can be compressed to a conventional tablet. The release rate of the drug and its permeation across intestinal cells model (Caco-2) from TOPSi-IMC tablets was improved compared to the bulk IMC tablets. The dissolution rate and permeability of IMC from the tablets decreased with increasing ratio of the TOPSi-IMC particles in the formulation. The phenomenon is, presumably, a result of the loss of unique pore structure of the particles due to deformation of the particles under the compression load. (C) 2011 Elsevier B.V. All rights reserved.