Physico-chemical considerations in the development of an ocular polymeric drug delivery system

A silicone-based prepolymer was used as the major component for the fabrication of novel ocular devices. Gentamicin sulphate was used as a probe drug, due to its high aqueous solubility and widespread application. Mechanical properties of films containing the drug before and after gamma sterilization and exposure to heat were found to be unchanged. The hydrolytic stability of the polymer films was uncompromised by gamma sterilization. However, high pressure liquid chromatography analysis of the drug released from polymer matrices exposed to heat for long time periods indicated a small amount of degradation. The drug release rates of the devices were found to be affected by gamma irradiation and exposure to heat.