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A b s t r a c t Present study involves the formulation and evaluation of floating tablets Ranitidine hydrochloride by direct compression method by using HPMC K4M, HPMC K100M as a synthetic polymers and Gellan Gum (low acyl) as a natural polymer with addition of sodium bicarbonate and citric acid as effervescent agent. The physicochemical compatibility of the drug and the polymers was studied by infrared spectroscopy and differential scanning calorimetry. The results suggested that drug and the polymers were physicochemically compatible with each other. The effect of synthetic and natural polymers on the drug release and floating properties of tablet were investigated. Formulation was optimized on the basis of pre compression and post compression parameters, floating lag time, total floating time and in vitro drug release study was carried out. The floating lag time, dissolution studies indicated that formulation F11 with drug: polymer ratio 5:4 exhibited sustained release of drug and followed Korsemeyer Peppas kinetics. Natural polymer (Gellan Gum) showed better results for sustained drug release properties than synthetic polymer. The floating lag time was found to be increase significantly with increase in concentration of polymer and drug release was found to decrease with increase concentration of polymers