Various approaches have been paused to increase the duration of oral dosage form in the stomach, including floating systems, swelling and expanding system, modified shape system, high density systems and other delayed gastric emptying devices. (Magnetic systems, Super porous -biodegradable hydrogel systems). Hydrodynamically balanced systems (HBS) -incorporated buoyant materials enable the device to float. Raft systems incorporate alginate gels - these have a carbonate component and, upon reaction with gastric acid, bubbles form in the gel, enabling floating. Swelling type of dosage form are such that after swelling, this product swell to extent that prevent their exit from the stomach through the pylorus. As, a result, the dosage form retained in the stomach for a longer period of time. These systems may be referred to as a "Plug type system", since they exhibit tendency to remain logged in the pyloric sphincters.