For almost four decades, both natural and synthetic polymers have been investigated for use as carriers for controlling drug dosage. This coalition of polymeric materials with the pharmaceutical science led to the innovation in the design and the development of novel drug delivering systems. The purpose of the polymers in such system is to deliver drugs to target pathological cells in order to increase the effectiveness of drugs thus reducing their undesirable side effects. Besides, the polymer core also protects the drugs from the physiological environment in vivo and thus increases the bioavailability of the drug to the patients. Hence, the polymeric drug delivering systems offer some unambiguous advantages such as localized and sustained delivery of the drug.This becomes especially important for toxic drugs which are related to various systemic side effects. In addition, for polymers to be used as drug carriers, they should have a well defined structure, should be biocompatible and non toxic. This led to invention of novel polymers with desired physicochemical properties to exploit them in drug delivery systems.
