Oral controlled release dosage forms: dissolution versus diffusion

Selection of the appropriate release mechanism is not a straightforward process, as it requires a balance based on the desired target, the API properties and the technological challenges of the dosage form structure. Diffusion, dissolution or a combination of both could be adequate without an absolute superiority of one mechanism over the other. The combination of in vivo predictive dissolution systems, with mathematical modeling of the release mechanism and its correlation with formulation composition could help to design prototype candidates, with enhanced probabilities of success in human clinical trials.