Objective: The objective of this present investigation was to develop micro matrix sustained release dosage form of losartan potassium using combination of hydrophilic swellable polymers (sodium alginate and guar gum) to obtain a desired sustained drug release. Methods: Ionic gelation technique was used to fabricate all the formulation due to its simple, cost effective and non consumption of organic solvents nature. The effect of polymeric ratio and its blend on dependent parameters (i.e. various physicochemical parameters and in vitro drug release) were studied to optimize the concentration of polymeric blend required for 12 h. sustain release. In vitro wash off test and stability study was performed to investigate the mucoadhesion nature and shelf life of the optimized formulation. Results: Concentration of guar gum was found to be the main influential factor for 12 h sustained drug release. The mucoadhesion property was strongly dependent on the pH of the medium and the polymeric concentration in the formulations. In vitro drug release study proposed a combined drug release mechanism, partially involving the spheres erosion and drug diffusion from the micro matrix system. SEM study and stability analysis revealed that optimized microspheres were almost spherical in shape with a shelf life of about 2.56 years. These prospective results also revealed that sodium alginate alone could not efficiently control the drug release, while combination with guar gum could retard the release of losartan potassium for desire period. Conclusion: So it is concluded that combination of hydrophilic swellable polymers is an essential polymeric blend to deliver losartan potassium for prolong period and improve patient compliance. Pha rm a c e u tic a An a ly t ic a A cta