Synthesis and in vitro characterization of freeze-dried doxorubicin-loaded silica xerogels

The sol–gel technique can be used as a new method for loading an anticancer drug (doxorubicin hydrochloride) within a silica xerogel matrix. Procedure to obtain a doxorubicin-loaded silica xerogel was specially developed to avoid decomposition of doxorubicin and to facilitate the formation of narrow-pore structure. The main purpose of this paper was to examine molecular and macroscopic structural changes in the novel silica material under the desired conditions of in vitro doxorubicin release. Simulated body fluid (SBF, Kokubo solution) at 37 °C with ion concentrations nearly equal to those of human blood plasma (pH 7.4) was used for in vitro evaluation. The release test of doxorubicin was performed under static conditions with a regular replacement of SBF. The characterization of silica xerogel was performed by using SEM, BET, IR, and nitrogen gas adsorption/desorption measurements. The thermal decomposition behavior of this material was also reported.