The aim of the present study was to evaluate four hydrophobic polymers as a rate retarding agent. Eudragit L-100, kollidon-SR, ethyl Cellulose and Veegum were used as Hydrophobic polymers. The polymers and excipients were blended and tablets were prepared using hydraulic press tablet machine. It was found that the tablets which were blended with ethyl cellulose and veegum, failed to provide release retardation. But the tablets in which Eudragit L-100 and Kollidon-SR were present, provided better release retardation. The USP paddle method was selected to perform the dissolution test, carried out in 750 ml 0.1 HCl for first two hours and 1000 ml Phosphate buffer of pH 6.8 for six hours. It should be noted that the release of the drug was very low in the acidic medium. That’s why, the dissolution data in the buffer stage (the very small amount of drug that was released in the acid stage included in the 1hour of the buffer stage) were only considered for the treating the data in various pharmacokinetic models. So, the original MDT value of each formulation would be the MDT value indicated (in bar diagram) plus 2 hours. It was found that, the MDT values of the formulations with the higher Eudragit L-100 content were the higher compared to the MDT values of the formulations with the higher Kollidon-SR content.