title: Electrically controlled release of benzoic acid from poly(3,4-ethylenedioxythiophene)/alginate matrix: effect of conductive poly(3,4-ethylenedioxythiophene) morphology.
abstract: A drug-loaded conductive polymer/hydrogel blend, benzoic acid-loaded poly(3,4-ethylenedioxythiophene/alginate (BA-loaded PEDOT/Alg) hydrogel, was used as a carrier/matrix for an electrical stimuli transdermal drug delivery system (TDDS). The effects of cross-linking ratio, PEDOT particle size, and electric field strength on the release mechanism and the diffusion coefficient (D) of BA were examined by using a modified Franz-diffusion cell. The diffusion scaling exponent value of BA is close to 0.5 which refers to the diffusion controlled mechanism, or the Fickian diffusion as the BA release mechanism. The D increased when there was a decrease in the cross-linking ratio due to the mesh size-hindering effect. When increasing electric field strength, the D of BA-loaded PEDOT/Alg hydrogel increased because the cathode-BA(-) electrorepulsion, electroinduced alginate expansion, and PEDOT electroneutralization simultaneously occurred. The highest D belonged to a blend with the smallest PEDOT particle and highest electrical conductivity. The D of BA was a function of the matrix mesh size except when drug size/mesh size was lower than 2.38 × 10(-3), where D of BA became mesh size independent as the matrix mesh size was extremely large. Thus, the fabricated conductive polymer hydrogel blends have a great potential to be used in TDDS under electrical stimulation.
authors: Conductivity and Electroactive Polymer Research Unit, The Petroleum and Petrochemical College, Chulalongkorn University , Bangkok 10330, Thailand.
authors: Nophawan
authors: N
authors: Paradee
authors: Anuvat
authors: A
authors: Sirivat
mesh_terms: D000464:Alginates / Q000737:chemistry*; D019817:Benzoic Acid / Q000737:chemistry*; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000737:chemistry*; D003692:Delayed-Action Preparations / Q000737:chemistry*; D004058:Diffusion; D004599:Electric Stimulation Therapy / Q000379:methods*; D004560:Electricity; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D020100:Hydrogels / Q000737:chemistry*; D007700:Kinetics; D016014:Linear Models; D008956:Models, Chemical; D010316:Particle Size; D058105:Polymerization; D011108:Polymers / Q000737:chemistry*; D013055:Spectrophotometry, Infrared; D013817:Thermography; D013818:Thermogravimetry
chemical_list: D000464:Alginates; D019086:Bridged Bicyclo Compounds, Heterocyclic; D003692:Delayed-Action Preparations; D006603:Hexuronic Acids; D020100:Hydrogels; D011108:Polymers; C121383:poly(3,4-ethylene dioxythiophene); D020723:Glucuronic Acid; D019817:Benzoic Acid