Two hydrophobic polymers Eudragit RL 100 and Eudragit RS 100 were used for preparing sustained release lamivudine tablet. In this study the effect of the thermal and solvent treatment on drug release, tensile strength was studied. Increasing the sintering duration increase in the sustained release and also increase in hardness of tablet. FTIR, XRD and DSC study shows no chemical interaction between drug and polymer and no polymorphic changes in drug due to sintering. SEM analysis conformed the redistribution of polymer and smoother tablet. The solvent treatment gives more sustained release of drug compare to thermal treatment.