Synthesis and characterization of electrically responsive poly(acrylamide)-grafted-chondroitin sulfate hydrogel for transdermal drug delivery application

Electrically-responsive transdermal delivery systems (ETDS) were developed utilizing poly(acrylamide)-grafted-chondroitin sulfate (PAAm-g-CS) copolymer. A nitrogen environment based free radical polymerization was used to synthesize electrically responsive PAAm-g-CS copolymer. This PAAm-g-CS hydrogel was used as drug reservoir and cross-linked blend films of CS and poly(vinyl alcohol) as rate controlling membranes (RCM). The drug permeation decreased with increase in the concentration of glutaraldehyde and RCM thickness; while drug permeation was increased with increasing electric stimulus from 2 to 8 mA. Nearly, three-fold increase in flux was observed with the application of electric stimulus. The permeation study under “on–off” electric stimulus suggested that the higher drug permeation was observed under “on” condition of electric stimulus and permeation was decreased when electric stimulus was “off”. The histopathology evaluation confirmed the changes in skin structure when electrical stimulus was applied. Hence, the PAAm-g-CS hydrogel could be a resourceful material for on-demand discharge of medication.