In situ preparation and drug release properties of validamycin-loaded silica hollow microcapsules

Validamycin-loaded silica hollow microspheres were prepared by in situ hydrolysis of tetraethyl orthosilicate (TEOS) in Water-Oil (W/O) emulsions. The microspheres were characterized by SEM, XRD, FT-IR and particle size distribution. The results indicated that the drug-loaded microspheres had an amorphous hollow spherical structure with the diameters of 7.5~15 μm. The amount of validamycin entrapped in the microspheres was about 31.9%(ω). Sustained-releasing studies showed that the release time was about 240 min and more than 90% of the loaded drug in the microspheres was delivered, indicating good sustained release behavior of the drug-loaded microspheres.