Discovery of a new chemical entity that exerts pharmacological effects for curing or treating diseases or relieving symptoms is only the first step in the drug developmental process. In the developmental cycle of a new drug, the delivery of a desired amount of a therapeutic agent to the target at a specific time or duration is as important as its discovery. In order to realize the optimal therapeutic outcomes, a delivery system should be designed to achieve the optimal drug concentration at a predetermined rate and at the desired location
