Electrical Field Responsive Polypyrole in Poly(acrylic acid) Hydrogel for Transdermal Drug Delivery

Transdermal drug delivery system is a system that delivers a drug into a body at a desired site and rate. The conductive polymer-hydrogel blends between polypyrrole (PPy) doped with an anionic drug and poly(acrylic acid) (PAA) were developed as the matrix/carriers of the drug for the transdermal drug delivery in which the characteristic releases depend on the electrical field applied and the crosslinking ratio. The PAA films and their blend films were prepared by solution casting using ethylene glycol dimethacrylate (EGDMA) as a crosslinking agent. A mechanical blending of PPy particles and PAA matrix was then carried out. The drug diffusions of blended PPy/PAA hydrogel and the non-blended one were investigated and determined by using a modified Franz-diffusion cell with an acetate buffer, pH 5.5, at 37 degrees C, for a period of 48 h to determine the effects of crosslinking ratio and electric field strength. Amounts of the released drug were measured by a UV-visible spectrophotometer. The diffusion coefficient of the drug was determined through the Higuchi equation, with and without an electric field at various crosslink ratios. The diffusion coefficient decreases as the crosslinking ratio is increased and the diffusion coefficient increases with applied electric field up to 1.0 V.