An improved process for enhancement of loading of fenofibrate using pre-mixed feed with mesoporous silica particles by supercritical carbon dioxide-assisted diffusion

This work pertains to intensification of the process of fenofibrate loading in MCM-41 mesoporous silica particles with respect to a reported process in the medium of organic solvent vapour. The intensification is attributed to the use of supercritical carbon dioxide (scCO₂) and premixing of fenofibrate with MCM-41. The superior transport properties of scCO₂ enhance diffusion of fenofibrate to surface of MCM-41. The premixing reduces the external diffusional resistance to transport of fenofibrate to MCM-41. The internal diffusion of fenofibrate through the pores of carrier is enhanced due to high driving force for its transfer into the pores. The effects of fenofibrate to feed ratio, contact time, and depth of the mixed feed reveal faster and enhanced loading of fenofibrate as compared to conventional methods. A high loading of fenofibrate (44.7 wt%) was achieved in merely four hours of contact time. The fenofibrate loading by adsorption is enhanced by an additional loading (>20 wt%) due to precipitation during pressure release. The loaded fenofibrate is in amorphous form and stable even after storage for three-and-half months. The release kinetics confirm enhanced release of the loaded fenofibrate, and about 78 % of it released in 60 min.