The study was undertaken with an aim to improve the efficacy and reduce the adverse effect of drug, by combination therapy of  Diltiazem HCL and Quercetin dihydrate. In the present research 22 formulations were developed using design expert software with response surface methodology. In which the effect of superdisintegrant, type of superdisintegrant, effect of diluents, formation of solid dispersion studied for their in vitro release  from pellets. The result depicted that the formulation containing superdisintegrant crospovidone, diluent lactose and presence of surfactant  showed good disintegration time and in vitro drug release. Key words: Diltiazem HCL, Quercetin, Pellets, Immediate release