Abstract
An ideal colon specific drug delivery system needs to perform multiple functions like greater bio availability, less toxicity and higher therapeutic efficacy, all of which require high degree of smartness. This article focuses on the overview of the stimuli-responsive polymers and various nanodrug delivery systems which have found applications in colon specific delivery of drugs as this system provide a link between therapeutic need and drug delivery. These polymers exhibit a non-linear response to a small stimulus leading to a macroscopic alteration in their structure/properties. Stimuli responsive polymers display a significant physio chemical change in response to small changes in their environment (temperature, pH, light etc.). Colonic drug delivery has gained increased importance in treating diseases like Crohn's disease, ulcerative colitis, colon cancer etc. The expansion in the development of polymers based system with greater flexibility, versatility and unexplored potential enables new opportunities for them in uplifting bio medicine. Applying the concepts of smartness in the context of clinically relevant therapeutic and diagnostic systems, it can prelude in a new era of 'smart' therapeutics that can improve the health care fields. In particular, due to its high sensitivity to the stimuli, this system has been identified as a sensible platform for releasing drug at suitable site and at appropriate time.