This study was carried out to synthesize silica nanoparticles for Sustained drug release. Synthesis of nanosilica was carried out from Rice husk ash by sol-gel method and the size distribution was controlled by using different surfactants like, a cationic (CTAB) and anionic (SDS) surfactant. The quercetin – a flavonoid was successfully incorporated in nanosilica synthesized using 2% SDS surfactant and was grafted with PEG 4000. The quercetin loading capacity into nanosilica was determined depending on different concentrations used for loading. The release of this loaded quercetin was traced using UV spectrophotometer for sustained release in Ethyl acetate. The % release profile was also determined. The Antioxidant activity of the quercetin incorporated nanosilica was checked using a DPPH antioxidant assay.

Keywords : Silica nanoparticles, Rice husk ash, sol-gel method, Surfactants, CTAB, SDS, Quercetin, PEG 4000, Sustained release, Antioxidant activity, 2,2-diphenyl-1picrylhydrazyl(DPPH), UV spectrophotometer, Particle size analysis, SEM and IR spectroscopy.