Single- and double-layered nanocomposites prepared by encapsulation of lisinopril-loaded silica xerogels with the biodegradable polymer chitosan. The in vitro drug release profile from both the nanocomposites and bare nanospheres investigated. The single-layered nanocomposites (silica xerogel) showed an initial burst, followed by two sustained release stages lasting for 13 days. In comparison with the silica xerogel nanocomposites, the silica xerogel/ Chitosan nanocomposites released a reduced initial burst together with three sustained release stages. The silica xerogel/chitosan nanocomposites can provide additional advantages in the localized drug delivery applications, as compared to the silica xerogel.