Organosilicate-polymer drug delivery systems: controlled release and enhanced mechanical properties.

Dexamethasone-loaded poly(ethylene-co-vinyl acetate) (EVAc) nanocomposites were fabricated via solution-casting with three different organosilicates for study in a drug delivery system. X-ray diffraction (XRD) showed that all three nanocomposites were in an intercalated morphology. Release studies of dexamethasone into phosphate-buffered saline revealed that the presence of silicates reduced the rate of drug release, and this reduction was a function of volume fraction of silicate in the composite, as well as the aspect ratio of the silicate layers. It was also found that the presence of silicate in a nanocomposite resulted in an increase in the Young's modulus as compared to the pure polymer, and this increase was also a function of the volume fraction of silicate present as well as the aspect ratio of the silicate layers. Silicates are a viable additive to EVAc drug delivery systems, providing controlled release characteristics as well as enhanced mechanical properties in an economically and biologically safe manner.