An electrically responsive hydrolyzed polyacrylamide-grafted-sodium alginate (H-PAAm-g-SA)-based membrane-controlled transdermal drug delivery systems were developed and evaluated. The grafting reaction was confirmed by Fourier transform infrared spectroscopy, elemental analysis, and thermogravimetric analysis. On application of electric stimulus, the swollen H-PAAm-g-SA hydrogel was deswelled in the vicinity of electrodes. The drug release was greater in the presence of electric stimulus when compared with passive diffusion, and it was found to be dependent on the applied electric current strength, concentration of H-PAAm-g-SA copolymer in the reservoir, and cross-link density of rate-controlling membrane. A pulsatile pattern of drug release was observed when the electric stimulus was switched "on" and "off." The skin histopathology study suggested that, after application of an electrical stimulus, changes were in the structure of stratum corneum. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 115: 1180-1188, 2010