Hydrogels: Stimuli Responsive to on-Demand Drug Delivery Systems

Hydrogels are the three dimensional crosslinked network of polymeric materials, which have the ability to respond and adapt to the surrounding environment inside the human body. Hydrogels are the upcoming class of biomaterials, which act as excellent drug delivery systems. These materials have important characteristic feature that they respond to various external stimuli like pH, light, temperature, magnetic field, electric field and pressure. Present chapter gives a broad overview of the recent hydrogels used for drug delivery using various external stimuli. Concluding remarks and viewpoints for the future development of stimuli responsive hydrogels are addressed.