The aim of the present study was to study effect of Xanthan gum and Chitosan in combination on effervescent floating matrix tablet of water soluble analgesic drug. Tapentadol hydrochloride. Tapentadol hydrochloride is a synthetic opioid used as a centrally acting analgesic and effective in both experimental and clinical pain. The half-life of the drug is about 4 hours and oral dose is 50 to 250 mg twice a day. To reduce the frequency of administration and to improve patient compliance, a sustained-release formulation of Tapentadol is desirable. The 32 full factorial design was employed to study effect of Xanthan gum and Chitosan in combination on Tapentadol hydrochloride floating tablets. Sodium bicarbonate was incorporated as a gas-generating agent. Combination of polymers Xanthan gum and Chitosan was used to retard drug release. The concentration of polymers was varied and their effect on floating time, drug content, % drug release after 8 hours, swelling index and hardness of the tablets was studied. The formulation was evaluated using Infrared-red spectroscopy and Differential Scanning Calorimetry to study drug-excipient compatibility. From the factorial batches, it was observed that formulation containing combination of 20% sodium bicarbonate and 10% citric acid shows optimum floating ability whereas the formulation containing 20% Xanthan gum and 28% Chitosan shows optimum sustained drug release pattern. X ray study of the optimized formulations showed gastro retention for 6 hrs indicating successful floating GRDDS of Tapentadol HCl.