In-vitro controlled release of doxorubicin from silica xerogels.

This study aimed at the development of a novel silica xerogel matrix as a delivery tool for an anti-cancer drug. Doxorubicin was incorporated as a hydrochloride salt during hydrolysis and polycondensation of tetraethylorthosilicate (TEOS) in the sol-gel process. The effect of sol-gel synthesis parameters (drug concentration, size of the device and lyophilizing process) on the release rate of the drug were investigated. In addition, dissolution rate, as well as weight loss of silica xerogel, was evaluated. In general, both the lyophilizing process of xerogels and the increase in size of non-lyophilizing device significantly decrease both the rate of drug release and the rate of dissolution of matrix. The overall release process was found to be governed by diffusion control and simultaneous zero-order dissolution of the xerogel.