The aim of this work is to prepare and evaluate sustained-release matrix diclofenac sodium (DS) tablets using simple diluents by either direct compression or wet granulation techniques. The prepared tablets were evaluated for physical characteristics and in vitro dissolution rate, and the results were compared to a standard commercial product (Voltaren^® 100 SR tablets). The effect of cety1 alcohol (CA) amount on the physical characteristics of DS tablets prepared by wet granulation using a mixture of dibasic Całcium phosphate:Avicel PH102 as a diluent was studied. The results show that tablets prepared with a mixture of dibasic calcium phosphate:Avicel PHI02 as a diluent using wet granulation technique are superior in the release rate retardation. Increasing CA amount results in an increase in tablet disintegration time, a decrease in tablet friability, and retardation in DS release As a conclusion, formulations prepared by wet granulation show a lower release rate in both acidic and buffer media compared to those prepared by direct compression using the same diluent, and increasing CA amount above 30 mg does not Significantly affect the release rate but has a significant effect on release mechanism and release kinetics.