Controlled drug delivery system is to make sure safety and 
to improve effectiveness of the drugs as well as patient 
compliance. A controlled release system includes any 
delivery system that achieves slow release of the drug over 
an extended period of time. This is achieved by better 
control of plasma drug level and less frequent dosing. 
Successful commercialization of a controlled release 
formulation is frequently challenging and involves 
consideration of many factors such as physiochemical 
properties of the drug, physiological factors, and 
manufacturing variables. The rationalization for the 
development of controlled release drug delivery system of 
a drug is to improve its therapeutic benefits, minimizing 
its side effects even as improving the management of the 
diseased condition. It is the purpose of this piece of 
writing to comprehensively review drug delivery system 
design for control release by discussing the recent patents 
available.