Silica was obtained from rice husk, this type of silica is also known as SiO2-rice, was investigated as drug delivery for the folic acid. The SiO2-rice was obtained from calcinations at 600 °C and its textural properties were compared with mesoporous silica (MS). The maximum folic acid adsorption on SiO2-rice was at the 18 % weight, while MS adsorbs 19 % weight. An important pH effect on the drug released was observed; both silicas released around 35 % of acid folic at pH 7, while at pH 3 only 3 % of the drug was released. Differential Thermal Analyzer analysis suggests that the folic acid was not crystallized into the porous of the silica; therefore, it is possible that the drug was trapped within the complex network of pores preventing their full release. However, the drug released for 400 μg of folic acid, a commercial dose, indicated that until 93 % of drug could be released for the silicas at pH of 5.5; a minor desorption was observed by commercial tablet. © 2014 Springer Science+Business Media New York.
Salazar Hernández, M., Salazar Hernández, C., Gutiérrez Fuentes, A., Elorza, E., Carrera-Rodríguez, M., & Puy Alquiza, M. J. (2014). Silica from rice husks employed as drug delivery for folic acid. Journal of Sol-Gel Science and Technology, 514-521. https://doi.org/10.1007/s10971-014-3378-5