Study of Additive Effect on Mechanical Properties, Drug Release Behaviour and Mechanisms in a Monoli

In a monolithic controlled drug release system, the effect of drug and additives on release behaviour and mechanical properties of silicone elastomer were investigated. For this purpose the silicone matrixes containing different concentrations of progesterone, calcium carbonate and silicone oil as additives were prepared by mixing in thermo-mixer Haake and cured in specific conditions. Then the released drug was evaluated by a new analytical method and the mechanical properties were studied according to ASTM D 2240. The results indicate that the release profile that has been found by experimental data is in good agreement with Higuchi''s model. When silicone oil and progesterone concentration were increased in polymer matrix, the drug release was increased but the hardness was decreased. The drug release was decreased by addition of calcium carbonate but this additive had no effect on hardness.