Computer-aided design of bioerodible devices with optimal release characteristics: a cellular automata approach

The development of a computational tool to design bioerodible devices with optimal release characteristics is presented. This computational tool uses cellular automata and parallel iterations to model and simulate the release of bioactive agents (drugs) from bioerodible matrices. The simulations can accurately model surface erosion processes in multicomponent systems of arbitrary geometry and with different dissolution rates for each component. Simulation results are analysed to show how the overall release rates are affected by the intrinsic dissolution rates, drug loading, porosity and the dispersion of the drug in the bioerodible matrix. A strongly non-linear dependence of release rates on drug loading and the intrinsic dissolution rates of the solid components is obtained and the effects of phase dispersion on the variability of release rates are elucidated. Finally, guidelines are presented for screening of alternatives to minimize the development effort and experimentation required for designing devices with desired release characteristics.