American Chemical Society and American Pharmaceutical Association
Journal of Pharmaceutical Sciences vol:100 issue:10 pages:4295-4301
A new synthesis route for large spherical particles of amorphous microporous silica (AMS) was developed. These novel spherical porous particles with diameter of around 100 :m and pore diameter smaller than 2nm were prepared using an oil drop method. Molten ibuprofen was successfully loaded into the AMS pores. In vitro release experiments revealed that ibuprofen was released from the spheres via a slow pore diffusion process lasting up to 14 days. Experimentally determined diffusion coefficients of ibuprofen in the porous spheres were of the order of 10−15–10−16 m2 s−1. The present findings reveal the potential of AMS spheres for controlled release of small drug molecules over long time periods. The spherical shape of the AMS particles is advantageous in formulation processes as it provides adequate powder flow properties and reliable release profiles.