Numerical Modeling of Controlled Release of Drugs From Silicone Elastomers

Silicone based medical devices, where the function is enhanced by the release of a drug or other bioactive compound, are of interest for a variety of applications. Such a device must release the drug at a given rate over a given period of time, while maintaining the shape and material properties required for the primary function of the device. Achieving these goals in an optimal fashion is challenging if one relies solely on traditional experimental work. Accurate numerical modeling compliments experimentation by allowing fast evaluation of parameters and subsequent validation of a select set of promising cases. Our ultimate goal is a numerical model which can accurately predict drug release characteristics from silicone elastomers with complicated geometry and inhomogeneous drug dispersion. In this work, we lay the foundations for such a comprehensive model. We describe a numerical model for simple geometries and carry out a parametric study for various initial and boundary conditions. We validate our modeling work by comparison with experimental trials, carried out by our own group. The work is carried out in a group composed of engineers and pharmaceutical scientists, ensuring step-by-step validation of models against experimental results.