HEPARIN RELEASE FROM POLYMER COMPLEX

An electro-erodible polyelectrolyte complex was prepared and investigated for a pulsatile drug release system. An insoluble polyelectrolyte complex was formed by combining two water-soluble polymers, poly(allylamine) and heparin. Upon the application of an electric current, a rapid structural change of the complex occurred, dissolving the polymer matrix in proportion to the intensity of an applied electric current. The disruption of ionic bonds in the polymer matrix attached to the cathode and subsequent release of heparin was due to the locally increased pH near the cathode (resulting from hydroxyl ion production). Thus, the release pattern of a model bioactive macromolecule, heparin, followed the applied electric current, primarily due to surface erosion of the polymer matrix.