Drug Release From Porous Spherical Particle: Diffusion Model With an Intermediate Complex Formation

Abstract

This publication proposes a new model of drug release from a spherical particle that takes into account the transfer of the drug and the porous particle into the solution by forming an intermediate complex with the bio carrier, one of the components of the solution. The mathematical model is reduced to a dimension-less form that is convenient for qualitative analysis of the process. The problem is realized numerically. The initial stage of filling a porous particle with a bio carrier and stage of drug release into environment were analyzed. Two main types of kinetic curves corresponding to diffusive and convective modes were revealed. The kinetic curves with the initial stage of drug release delay were revealed. The model was in effects (unobvious at first glance) related to the interaction of opposite factors affecting the drug release. The different types of kinetic curves obtained on its basis correspond to different observational conditions, types of particles, and properties of bio fluids. This model can be improved to describe and predict drug release kinetics not only from single porous particles, but also from containers of more complex shape.