The objective of this investigation was to prepare extended release tablet containing interpolyelectrolyte complex (IPEC) formation technique using Eudragit E100 and Eudragit L100 polymers andEE was selected as the cationic polymer. The other cationic types of Eudragit cannot be used because they are insoluble in aqueous solutions. And, EL, which is usually used as an enteric coating, was used as the anionic polymer The main goal of controlled drug delivery systems is to improve the effectiveness of drug therapies. Controlled drug delivery is delivery of drug at a rate or at a location determined by needs of body or disease state over a specified period of time. In which the drug is delivered over an extended time period. to study its in vitro release and in vivo absorption. The design of dosage form was per-formed by choosing Eudragit E100, EudragitL100, Mg Steret and Talk and PVP-K30 as granulating polymers. Granules were prepared by composing drug with interpolyelectrolyte complex. Optimized formulation of Desvenlafaxine succi-nate was formed by using interpolyelectrolyte complex (IPEC) formation technique using Eudragit E100 and Eudragit L100 polymers This extended the release period up to 10 h in vitro study. Similarity factor and mean dissolution time were also reported to compare various dissolution profiles. The network formed Eudragit E100, L100 polymers had been coupled satisfactorily with the controlled resistance. Biopharmaceutical study of this optimized dos-age form in rabbit model showed 10 h prolonged drug release in vivo. A close correlation (R2 = 0.9833) was established between the in vitro release and the in vivo absorption of drug. The results suggested that wet by interpolyelectrolyte complex (IPEC) formation technique, is a suitable method to formulate sustained release Desvenlafaxine succinate and it can Perform therapeutically better than conventional immediate release dosage form.