Incorporation of indomethacin nanoparticles into 3-D ordered macroporous silica for enhanced dissolution and reduced gastric irritancy.

In the present study, we exploited for the first time the potential of 3-D ordered macroporous (3DOM) silica as matrix for drug nanoparticles, in order to obtain proper control over drug particle size in the sub-micrometer range, enhance the dissolution rate, and reduce gastric damage. 3DOM silica matrix with 3-D spherical pores of 200 nm was successfully created and then loaded with IMC nanoparticles at various drug-silica ratios. A rapid release profile for IMC nanoparticle formulations was achieved in comparison with microsized IMC and a commercial capsule, which could be attributed to both increase in the specific surface area and decrease in the crystallinity of IMC, as well as the hydrophilic surface and the interconnected pore networks of 3DOM silica. Reduced gastric damage of IMC was demonstrated, and the protective effect may arise from the reduction in drug particle size as well as encapsulation effect of 3DOM silica.