Over the last few years the controlled drug delivery becomes a predominant method for treatment for most of the diseases. In this book the importance of porous osmotic pump tablets over the matrix tablets for controlled delivery of Diclofenac sodium (DS) were elucidated. The solubility of DS is highly pH dependent. The matrix tablets (MT) were prepared by direct compression method. The porous osmotic pump tablets (CPOP) were designed using D-Optimal design. All formulations were evaluated for various physicochemical parameters and in vitro drug release kinetic studies were determined and compared. ANOVA studies in drug release of all the formulations were determined. Numerical optimization technique was applied to determine the best formulation. The most satisfactory formulations in MT and CPOP were studied for the influence of pH and agitation intensity on release of drug. The membrane morphology of the CPOP was studied using scanning electron microscopy (SEM). The porous osmotic pump tablets provide prolonged, controlled, and gastrointestinal environment-independent drug release than matrix tablets.