In vitro release and in vitro-in vivo correlation for silybin meglumine incorporated into hollow-type mesoporous silica nanoparticles.

Background: The purpose of this study was to develop a sustained drug-release model for water-soluble drugs using silica nanoparticles.
Methods: Hollow-type mesoporous silica nanoparticles (HMSNs) were prepared using Na(2)CO(3) solution as the dissolution medium for the first time. The water-soluble compound, silybin meglumine, was used as the model drug. The Wagner-Nelson method was used to calculate the in vivo absorption fraction.
Results: The results of transmission electron microscopy and nitrogen adsorption revealed that the empty HMSNs had uniformly distributed particles of size 50-100 nm, a spherical appearance, a large specific surface area (385.89 ± 1.12 m(2)/g), and ultralow mean pore size (2.74 nm). The highly porous structure allowed a large drug-loading rate (58.91% ± 0.39%). In 0.08 M Na(2)CO(3) solution, silybin meglumine-loaded HMSNs could achieve highly efficacious and long-term sustained release for 72 hours in vitro. The results of in vitro-in vivo correlation revealed that HMSNs in 0.08 M Na(2)CO(3) solution had a correlation coefficient R(2) value of 0.9931, while those of artificial gastric juice and artificial intestinal juice were only 0.9287 and 0.7689, respectively.
Conclusion: The findings of in vitro-in vivo correlation indicate that HMSNs together with Na(2)CO(3) solution could achieve an excellent linear relationship between in vitro dissolution and in vivo absorption for 72 hours, leading to a promising model for sustained release of water-soluble drugs.