Theoretical study of diffusional release of a dispersed solute from cylindrical polymeric matrix: A novel configuration for providing zero-order release profile

Abstract

• A novel design for polymeric matrixes , containing dispersed solute, has been suggested for providing zero-order release. • Mathematical modeling and simulation have been carried out to evaluate the performance of the suggested system. • The effect of coating degradation rate on the release profile has been assessed through the mathematical simulation. • The effect of solute loading level on the release profile has been assessed through the mathematical simulation. • The suggested system is able to eliminate burst release at initial time and provide approximate zero-order behavior. In the context of controlled release drug delivery approaches, the systems providing zero-order release kinetics have special advantages. Through employing these systems, drug concentration could be maintained within the therapeutic window over release time; thus maximum effectiveness alongside minimized side effects of the drug are achieved. However, obtaining zero-order drug release is extremely challenging. One of the main obstacles is the fact that implemented devices should be designed to overcome the decreasing mass transfer driving force, especially, in polymeric systems in which diffusion mechanism is dominant. In this study, we developed a new configuration of a polymeric matrix containing dispersed solute which provides sustained zero-order release. A combination of two innovative approaches including separating baffles and a two-layer coating was proposed to be incorporated into the conventional cylindrical polymeric matrix to induce zero-order release behavior. Then, an approximate mathematical model was developed to investigate the performance of the system under different conditions. The simulated results showed the potential of proposed configuration to be used as a carrier for sustained zero-order release.