Swelling and Drug Release in Polymers through the Theory of Poisson-Kac Stochastic Processes

Experiments on swelling and solute transport in polymeric systems clearly indicate that the classical parabolic models fail to predict typical non-Fickian features of sorption kinetics. The formulation of moving-boundary transport models for solvent penetration and drug release in swelling polymeric systems is addressed hereby employing the theory of Poisson-Kac stochastic processes possessing finite propagation velocity. The hyperbolic continuous equations deriving from Poisson-Kac processes are extended to include the description of the temporal evolution of both the Glass-Gel and the Gel-Solvent interfaces. The influence of polymer relaxation time on sorption curves and drug release kinetics is addressed in detail.