Role of dissolution studies in controlled release drug delivery systems

The concept of dissolution was explained by Noyes and Whitney in 1897, and since then there has been a tremendous amount of research that has gone int o the field. This has resulted not only in a better understanding of the pr ocess, but also in the development of various applications in different fie lds. In the context of pharmaceutical drug delivery systems the dissolution process is described as the phenomenon of drug availability from the dosag e form after its administration. However, the drug dissolution process from dosage forms has gained popularity only in the last four decades and in a real sense with the evolution of controlled release technology. The subject of controlled drug delivery is being widely pursued the world over to impr ove clinical efficacy of the drugs and enhance patient compliance. Controll ed release is based upon the principle of drug dissolution (now more common ly described as drug release) at a precisely controlled rate, resulting in a characteristic drug dissolution profile. These dissolution studies are so critical that today they are the most frequently used tools in the develop ment, characterization and utilization process of controlled release formul ations. This review is an update on the recent developments in the applicat ion and utilization of dissolution studies in the development of peroral co ntrolled release formulations.