Raft-forming in-situ gel systems are innovative gastro-retentive drug delivery systems designed to enhance gastric residence time and improve therapeutic efficacy. These formulations are administered as liquids and undergo rapid gelation in the acidic environment of the stomach. The mechanism involves ionic cross-linking of polymers such as sodium alginate in the presence of calcium ions, along with carbon dioxide generation from gas-forming agents like sodium bicarbonate. The released gas becomes entrapped within the gel matrix, forming a low-density floating raft that acts as a physical barrier against gastric reflux and provides sustained drug release. Due to their prolonged gastric retention, controlled release behavior, and improved patient compliance, raft-forming systems represent a promising approach for the management of acid-related disorders and localized gastric drug delivery.
Nazirkar* et al. (Mon,) studied this question.