Analytical review of drug dissolution and release kinetic models

Kinetic study of drug dissolution and release is of importance from different points of view including quality control, comparison, bioavailability of drug dosage forms and delivery systems. Thus, in the present work different kinetic models available in many scientific sources are reviewed analytically. Several equations and laws of dissolution and release were gathered from many sources. The models then were categorized into two general groups of applied to pure solids and conventional dosage forms as well as controlled release systems. Each group was further classified into subgroups for analytical purposes. The analytical review indicates that the models are essentially based on theoretical, semi-theoretical and empirical principles. Also some of the models are applicable for all forms i.e. pure solids, conventional forms and controlled release systems. Depending on the processes involved, the drug dissolution and release kinetic models are versatile. The prominent mechanisms of the processes which determine the kind of suitable kinetic model are diffusion, dissolution, osmosis and combination of these phenomena.