Macromolecules therapeutic and curative efficiency are generally subordinated to their ability to diffuse through tissues and mucus. Recently, several mathematical models which describe diffusion profiles of macromolecules in different organic tissues have been developed.Mucosal tissues remain the most difficult to model. In fact, interaction between macromolecules and mucosal epithelia structures are sophisticated as long as bothmacromolecules and epithelia fibres are not easy to configure. In the last two decades, many interpretations ofmacromolecules diffusion through epithelia have been proposed, i. e. the elastic continuum, obstruction-scaling and tubularmediummodels. In this study, we propose amathematicalmodel which introduces conjointly macromolecules realistic geometrical characteristics and epithelia behaviour in terms of physical obstruction.