Dissolution-controlled transport from dispersed matrixes.

A simplified mathematical model for dissolution-controlled transport from dispersed matrixes is presented. Analytical solutions have been obtained previously when solute diffusion totally controls the transport process. However, when solute dissolution offers the limiting resistance to mass transport, the solution reduces to a form where the mass released varies directly with time. Experimental release rates of a drug from a dispersed polymeric matrix into water were measured for a range of drug particle sizes in order to test the applicability of the proposed model; the agreement between theory and experimental is good.