Preparation and characterization of carvedilol solid dispersions using hollow mesoporous silica nanoparticles

The aims of this study were to prepare hollow mesoporous silica nanoparticles(HMSNs)and to evaluate its effect on drug loading and dissolution. Carvedilol, a sparely water-insoluble drug has been selected as the model drug. Carvedilol solid dispersions were prepared by solvent evaporation method using HMSNs as the drug carrier and absolute alcohol as solvent. The solid dispersions were characterized by transmission electron microscope(TEM), scanning electron microscope(SEM), N₂ adsorption-desorption, FT-IR spectroscopy, differential scanning calorimeter(DSC)and X-ray diffraction(XRD). In vitro drug release behavior and the short-term stability were also investigated. The results showed that drugs were highly dispersed into the hollow cores and mesopores of HMSNs in amorphous form. In addition, the results of in vitro dissolution testing showed that the accumulated dissolutions of carvedilol solid dispersions could reach 95% within 60 min, when the mass ratio of the drug and the carrier was 1 ∶5. 3-Month accelerated stability testing obesrved no significant changes to drug dissolution and content presented in the solid dispersions. The significant improvement of drug dissolution demonstrated that HMSNs could provide good reservoirs or carriers for sparely water-insoluble drugs, and have high potential in future applications for oral delivery of therapeutic drugs.