Silica Aerogel Microparticles from Rice Husk Ash for Drug Delivery

The present work describes an improved process for preparation of silica aerogel microparticles (SAMs) for drug delivery from rice husk ash (RHA), an inexpensive source rich in biocompatible silica. The wet gel microparticles were produced by a solgel method using water-in-oil emulsion, where a mineral oil replaced vegetable oil for easy separation using less energy. Taguchi design of experiments was used to optimize the parameters controlling the solgel method. The wet gel particles were dried with supercritical carbon dioxide (scCO(2)) to obtain SAMs. They were characterized by their properties such as BET surface area, pore volume, pore diameter and morphology. The efficacy of the improved process was validated by loading a water insoluble drug, ibuprofen, and a food preservative, eugenol, in SAMs from scCO(2) medium. The release kinetics of ibuprofen and eugenol from the loaded SAMs was studied. High loading and fast release kinetics confirmed that SAMs produced by the process are suitable for drug delivery.