A study of the optimal diffusion distance of ibuprofen through the synthesis of different sizes of mesoporous silica

In this study, the effect of mesoporous silica nanoparticles (MSNs) particle size on the diffusion distance of ibuprofen (IBU) is revealed. MSNs with different particle sizes of 50, 100, 200, 300, and 400 ​nm were synthesized using sol-gel method. Structure features were characterized by small-angle X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and N 2 adsorption-desorption. Using ibuprofen as the model drug, the optimal IBU unilateral diffusion distance was obtained by measuring the IBU loading per square meter. Results indicated the MSNs with a particle size of 100 ​nm exhibited the highest pore utilization and the optimal unilateral diffusion distance of IBU in MSNs was about 50 ​nm. On this bases, hollow mesoporous silica nanoparticles (HMSNs) were prepared to increase the loading of IBU. The optimal drug loading was achieved when the thickness of the shell was equal to the optimal unilateral diffusion distance, further demonstrating the relationship between the optimal diffusion distance and the drug loading.