Development of new drug delivery system has become the requirement of today’s pharmaceutical industry. As the number of off-patent drugs and cost of new drug development increases, pharmaceutical companies are managing the life cycles of their products (from product launch to their withdrawal from the market) by adopting new and innovative delivery systems. This gives the pharmaceutical industry another chance to make the most of their current products. Oral route is the most preferred route for administration of drugs as the administration is easy and economic. But the problem is the loss of their functions due to the short residence in the body. About 80% of the administered drugs are excreted without being absorbed. This article comprehensively explains need of hydrogels and its modifications to prolong the residence time of drugs in the body, with brief introduction of associated other drug delivery systems.