To develop sustained release matrix tablet of Tramadol HCl that deliver drug for 24 hr and to be taken once in a day. Drug having high solubility and relatively shorter half-life suggests its suitability for an extended formulation. If it is formulated by conventional tablets, it will require multiple daily administrations which ultimately results into inconveniency to the patients and possibility of reduced compliance with prescribed therapy. Also fluctuation in plasma drug concentration leads to exaggerated side effects, this all limitations can be minimized by adopting extended release...