ABSTRACT Electroconductive hydrogels has been extensively studied in drug delivery systems because they combine the properties of hydogels with the conducting polymers in only one material. In this work, pyrrole was polymerized electrochemically into poly(acrylic acid) hydrogel. This material kept the swelling properties that are characteristic of hydrogels and the electroactivity of the conducting polymers. The hydrogel (with and without the conducting polymer) swelling degree depends on both the ionic strength and pH. As this material is responsive to changes in the electrical potential, pH and ionic strength, the safranin release presented different delivery profiles, in accordance to variations and combinations of these stimuli. The most interesting result was the achievement of the linear safranin release indicating a zero-order kinetics.
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