In vitro study of drug release from various loaded polyurethane samples and subjected to different non-pulsed flow rates

Abstract

Drug-eluting implants with a polymeric matrix are currently widely used and the interest of modeling their behavior is increasing. This article aims to present preliminary results of an in vitro under steady flow, study the behavior of drug-loaded polyurethane samples used as drug delivery matrices. Polyisocyanate and polyol synthesis supplied the polyurethane studied in this work. A molding and heat at 50 °C for about 30 min make it possible to prepare films from these components. The prepared samples are placed in the impermeable Plexiglas tube and they are in contact with the medium (distilled water). Tests have been performed without flow and three other cases with steady flow, at a temperature of 37 °C. The substance active incorporated in these films, as the drug, for carrying out the release tests is the C20H24C12N2O3. This drug supplied in granular form is composed of a mixture in the following proportions, 15 mg of diclofenac epolamine and 50 mg of diclofenac-sodium. Four sample variants were carefully prepared: pure-PU and PU loaded in a mass ratio of 10, 20 or 30%. Weighing, DSC, FT-IR, and DMTA are the methods used to analyze the samples. In addition, SEM micrographs are used to explore qualitatively the microstructure during the release tests. The kinetics in vitro of the drug release and water absorption by the polyurethane films are discussed in detail. The results show that these two quantities depend on the initial drug loading and the flow rate value, as a function of the in vitro incubation time.