Silica Aerogel Microparticles from Rice Husk Ash for Drug Delivery

Abstract

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 sol−gel 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 sol−gel 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.

Synthesis and biomedical applications of aerogels: Possibilities and challenges

“…The release profile of drugs loaded in silica aerogel is generally characterized by an immediate release of the drug due to the quick collapse and disintegration of the silica aerogel once in contact with aqueous solutions [18,171,201,206,207]. In general, the release rate of drugs with low water solubility is significantly increased when incorporated into silica aerogels if compared with the dissolution profile of the raw crystalline drug.…”

Rice husk/rice husk ash as an alternative source of silica in ceramics: A review

“…3.6 Silica aerogel SA is a synthetic nano-porous, ultra-light, structure-controllable, solid material, which possesses excellent characteristics such as super-low bulk density (0.03-0.5 g/ cm 3 ), huge porosity (80-99%), a high specific surface area (500-1500 m 2 /g), low thermal conductivity, catalysis and a low dielectric constant [116][117][118]. It has a wide range of technological applications, therefore such as in insulation materials for buildings, membranes, pollutant absorbents, microelectronics, catalytic supports, drug carriers and dielectric materials [119,120].…”

Biomass as a sustainable resource for value‐added modern materials: a review

“…Furthermore, both rMBG and rMBG‐FA have no cytotoxicity in normal cells and showed excellent biocompatibility. Rajanna et al 260. reported that high loading and fast‐release kinetics of ibuprofen and eugenol which confirmed silica aerogel microparticles (SAMs) is suitable for drug delivery.…”

“…It has been found that RSAMs have a mesoporous structure with a surface area 274 m 2 g −1 , total pore volume 0.67 cm 3 g −1 , and an average pore diameter of 8.6 nm. This surface area is about 60% less, and the pore volume is 80% less, than that of SAMs 260. Industrial wastes from burnt RH could also become a cheap source of mesoporous silica for applications in the pharmaceutical industry.…”