Anomalous diffusion of drug release from a slab matrix: fractional diffusion models.

Mathematical models for the release of drug from both non-degradable and degradable slab matrices in which the initial drug loading is greater than the solubility are presented in this paper. Taking the anomalous diffusions in the drug release processes into account, the fractional calculus is introduced to model the related phenomena. To describe different kinds of anomalous diffusions, corresponding fractional diffusion equations are adopted. By employing the integral transform methods, similarity solution method and perturbation method, exact and approximation solutions to the models are obtained.