Abstract
The diffusional drug release from matrix-type devices have numerically been solved for various drug delivery systems. The present matrix-type drug delivery systems include the devices which the drug loading is higher or lower than the solubility in the polymeric matrix. In the former system, a moving boundary problem is treated because the position of diffusion front, the boundary between dispersed and dissolved zone in the matrix, changes with time. In this study, we have solved the release kinetics from matrix-type devices containing dissolved or dispersed drug using a finite difference method for partial differential equations under various conditions. The present mathematical model can also analyze the diffusion boundary layer formed on the surface of the device and the sink or non-sink condition in the receptor compartment.
