To formulate and evaluate time dependent pulsatile drug delivery system of Montelukast sodium to deliver the drug with biological rhythm of asthma after predetermined lag time 5:30 hours. In preliminary study, The core tablet of Montelukast sodium was prepared by using direct compression method containing SSG, Croscarmellose sodium, Crospovidone, MCC and Starcap1500 to obtain fast disintegrating tablet for the selection of super disintegrating agent. PVAP, CAP and Ratio of Eudragit L 100: Eudragit S 100 was used as pH dependent polymer for coating the core tablets. Total 9 batches were formulated as per 32 full factorial design applied to check the effect of polymer ratio (Eudragit L 100: Eudragit S 100) and the effect of % weight gain on dependent variable lag time PRTs. These formulations were evaluated for physical parameters of tablet, drug -excipient compatibility study, lag time of rupture of PRTs and in-vitro drug release study. PDDS of Montelukast Sodium formulated using Croscarmellose sodium as super disintegrant and Eudragit L 100 and Eudragit S 100 as a coating polymers. Formulation M7 can provide site specific delivery with sigmoidal drug release.