Models of Simultaneous Transport of Water and Drugs in Hydrophilic Polymer Systems

Abstract

Abstract Different models have been developed in order to predict the behavior of systems consisting of hydrophilic polymer, water, and drug. The first model deals with the so-called matrix system of controlled drug release and describes the simultaneous transport of water and drug in swelling glassy polymers. The dependencies of physical/chemical parameters on the concentation of water, drug and on the mechanical properties of the polymer are used for justification and prediction of corresponding experimental results. The method of calculating the physical/chemical parameters is based on an experimental investigation of the structure of the polymer and the diffusion-kinetic process. The main aim of the development of the other model is to predict the mechanism and velocity of drug release in “reservoir polymer systems” for which the sorption and diffusion properties of water transport through a polymer membrane are most important. The main steps of drug release have been shown, and various dependencies of the diffusion coefficients have been studied in order to predict their influence on the mechanism and velocity of drug release.