Sustained Release Drug Delivery Systems: A Patent Overview

Sustained Release Drug Delivery System (SRDDS) is designed to release a drug at a predetermined rate by maintaining a constant drug level for a specific period of time with minimum side effects. Now a day's focus on the development of SRDDS has increased, as very few drugs are coming out of research and development and already existing drugs are suffering the problem of resistance due to their irrational use specifically in case of drugs like antibiotics. The major goal of designing SR formulations was intended to modify and improve the drug performance by increasing the duration of drug action, decrease the dosing frequency, reduced side effects, decreasing the required dose employed and providing the shortest possible time by using smallest quantity of drug administered by the most suitable route. SR dosage forms are designed to transport the blood level of a drug instantly to therapeutic concentrations by means of an initial dose portion and then maintain this level for a certain predetermined time with the continuation portion. SR of drugs in GI tract following oral administration is not affected by the absorption process. The major goal of SR dosage forms is the improvement of drug therapy assessed by the relationship between advantages and disadvantages of the use of SR systems. The present review article is useful in knowledge of highlighted formulation approaches, criteria for drug selection, different countries sustained release dosage form patents and advance novel research for SRDDS. The present review is concerned with the patent study of drug release through controlled or sustained release dosage forms. This patent review is useful in knowledge of sustained release dosage forms for its application.