Impregnation of mesoporous silica with mangiferin using supercritical CO2

The solvating power and diffusivity of supercritical carbon dioxide (scCO2) have attracted attention in recent years for the impregnation of polymers and porous matrices. This technique provides a final impregnated matrix that is free of solvents and it allows the use of thermosensitive drugs due to the relative low critical point of scCO2.The work reported here concerned the influence of parameters such as pressure, temperature, percentage of co-solvent, depressurization rate and time on the impregnation of mangiferin (MNG) into silica as a porous matrix. Increases in the values of the studied parameters led to an enhanced impregnation of MNG in all cases. Delivery profiles in simulated fluids were obtained. The profile for the gastric fluid shows a gradual release of MNG. The release of MNG in the intestinal fluid was faster than in the gastric fluid. The MNG was more soluble in the intestinal than in the gastric fluid.