ABSTRACT: A novel gastroretentive drug delivery system based on a polysaccharide substance from linseeds (Linum usitatissimum L.) has been developed as floating matrix tablets for Gatifloxacin. To achieve a desirable prolonged release profile of gatifloxacin, a number of formulations were created using a combination of linseed hydrogel (LSH) and various excipients. The drug release test was carried out mostly at pH 1.2. However, due to specific factors, the tablet may pass through the stomach and into the intestine, where it provided sustained drug release at intestinal pH 7.4. The results showed that sustained gatifloxacin release was related to LSH concentration and that drug release followed a non-Fickian diffusion pattern. The porous character of LSH with elongated channels was revealed by SEM of the tablets, which contributed to the swelling of the tablet and later promoted the release of gatifloxacin from the core of the tablet. An in vivo X-ray investigation was conducted to examine tablet disintegration and real-time floating, which proved the tablet's presence in the stomach for 6 hours. These findings suggest that LSH could be exploited to create novel gastroretentive sustained release drug delivery systems that have the added benefit of delivering drugs at all GIT pH levels.