In vitro release of cisplatin from sol-gel processed organically modified silica xerogels.

SiO2, SiO2/PEG and SiO2/PDMS xerogels were examined as polymeric carriers for the controlled release of cisplatin--an antineoplasmic medicine. Drug/carrier systems were prepared by the sol-gel method. The effect of organic substitution of the silica xerogel matrix and drying conditions on the release of cisplatin was evaluated. Based on the presented results of the study it may be stated that sol-gel method is useful for entrapping a cisplatin in the pores of organically modified silica gels and for releasing cisplatin mainly in the way of diffusion from the pores of the lattice under the in vitro conditions. The use of organic impurities in silica gel increased the release of cisplatin from xerogel (from 62% to 97% within 7 days), and thermal treatment of all xerogels with cisplatin at the temperature of 80 degrees C resulted in the acceleration of the drug release (2 days) and increase of the released drug (89-98%).