A wide variety of delivery system have so far been developed utilizing the unique infrastructure base of polymers. Various techniques and tools have been evolved to shape them into the system bearing desirable characteristics. The concept of drug therapies and types of drugs demand different formulations, fabrications conditions and release kinetics. No single polymer can satisfy all the requirements. Therefore there have been tremendous advances in area of biodegradable polymers over the years. Drug dosage forms contain many components in addition to the active pharmaceutical ingredient(s) to assist in the manufacturing process as well as to optimize drug delivery. Extensive applications of polymers in drug delivery have been realized because polymers offer unique properties which so far have not been attained by any other materials. Most of these products were compounded versions of conventional resin. Biodegradable polymers have been made possible the controlled delivery of proteins and peptides.