title: Physicochemical characterization and drug release properties of Eudragit E PO/Eudragit L 100-55 interpolyelectrolyte complexes.
abstract: The formation of interpolyelectrolyte complexes (IPEC) between Eudragit E PO (EE) and Eudragit L 100-55 (EL) was investigated, using turbidimetry, apparent viscosity measurements, elementary analysis and MT-DSC. The structure of the synthesized IPEC was investigated using FT-IR spectroscopy. The binding ratio of a unit molecule of EL with EE was found to be approximately 1:1 at pH 5.5. Based on the results of elementary analysis and FT-IR, the binding ratio of each component in the solid complexes was very close to that observed in turbidity and apparent viscosity measurements and indicate that the synthesized products can be considered as IPEC. As a result of electrostatic interaction between the polymer chains, the glass transition temperature of the IPEC increased significantly. Due to the structure of the IPEC, two maxima were observed in the swelling behavior as a function of pH. The release of the model drug ibuprofen (IBF) was significantly retarded from tablets made up of the IPEC as compared with individual copolymers, its physical mixture and Eudragit RL PO (RL), RS PO (RS).
authors.affiliation: Department of Pharmaceutical Chemistry, State Medical University of Kazan, Tatarstan, Russian Federation. mustaf@rambler.ru
authors.forename: Rouslan I
authors.initials: RI
authors.lastname: Moustafine
authors.forename: Igor M
authors.initials: IM
authors.lastname: Zaharov
authors.forename: Vera A
authors.initials: VA
authors.lastname: Kemenova
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D003692:Delayed-Action Preparations; D004337:Drug Carriers / Q000138:chemical synthesis / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007052:Ibuprofen / Q000737:chemistry*; D015394:Molecular Structure; D011109:Polymethacrylic Acids / Q000737:chemistry*; D012995:Solubility; D017550:Spectroscopy, Fourier Transform Infrared; D013607:Tablets; D044366:Transition Temperature; D014783:Viscosity; D014867:Water / Q000737:chemistry
chemical_list: D000180:Acrylic Resins; D003692:Delayed-Action Preparations; D004337:Drug Carriers; C446821:Eudragit L100-55; D011109:Polymethacrylic Acids; D013607:Tablets; D014867:Water; C518398:Eudragit E PO; D007052:Ibuprofen