A numerical treatment of drug release from a spherically shaped polymeric drug delivery device

This study concerns with the numerical solution of an existing model for solvent penetration and drug release from a spherically shaped polymeric drug delivery device. Our interest problem has a moving boundary that describes the interface between the glassy and rubbery states of the polymer. In spite of the previous works, in this paper an iterative finite difference approach based on variable time steps is established so solve the proposed problem. Because of the nonlinearity of the problem, the analytical solution of this problem can not be obtain and numerical results have been compared with the asymptotics form of solution based on applying a front-fixing scheme.