A Review on Polymers Used In In-Situ Gel Drug Delivery Systems

In situ gel drug delivery systems are used in sol form before administration in the body, but onceadministered, undergo gelation in situ, to form a gel. The formation of gel depends on factors liketemperature modulation, pH change, presence of ions and ultraviolet irradiation, electrical sensitivity,enzyme sensitive from which drug get released in a sustained and controlled manner. Typically, aqueoussolutions of hydrogels used in biomedical applications are liquid at ambient temperature and gel atphysiological temperature. The in situ gel forming polymeric formulations offer several advantages likesustained and prolonged action in comparison to conventional drug delivery systems. From amanufacturing point of view, the production of such devices is less complex and thus lowers theinvestment and manufacturing cost. This review stresses on the polymeric use of natural polymers andsynthetic polymers.