title: Structural transformations during swelling of polycomplex matrices based on countercharged (meth)acrylate copolymers (Eudragit EPO/Eudragit L 100-55).
abstract: With a view to the application in oral controlled drug delivery systems (DDS), the design of new interpolyelectrolyte complexes (IPECs) between countercharged types of Eudragit EPO (EPO) and Eudragit L 100-55 (L100-55) was investigated. The formation and composition of four new IPECs between EPO and L100-55 were established by elementary analysis. The structure of the synthesized IPEC was investigated using FTIR spectroscopy and modulated-temperature differential scanning calorimetry. The binding ratio of a unit molecule of EPO with L100-55 was found to range between 1:2.75 (Z = 0.36) and 1:0.55 (Z = 1.81) while increasing the pH value from 5.5 to 7.0. As a result of electrostatic interaction between the copolymer chains, the glass transition temperature of the IPEC increased significantly. A large pH-sensitive swelling behavior was observed for different structures of the IPECs. The outcome of swelling and diclofenac sodium release from the polycomplex matrices confirm that they have great potential to be used as a controlled DDS in specified regions of gastrointestinal tract.
authors.affiliation: Department of Pharmaceutical, Toxicological and Analytical Chemistry, State Medical University of Kazan, Kazan 420012, Russia. mustaf@rambler.ru
authors.forename: Rouslan I
authors.initials: RI
authors.lastname: Moustafine
authors.forename: Valerija L
authors.initials: VL
authors.lastname: Bobyleva
authors.forename: Aleksandra V
authors.initials: AV
authors.lastname: Bukhovets
authors.forename: Venera R
authors.initials: VR
authors.lastname: Garipova
authors.forename: Tatyana V
authors.initials: TV
authors.lastname: Kabanova
authors.forename: Vera A
authors.initials: VA
authors.lastname: Kemenova
authors.forename: Guy
authors.initials: G
authors.lastname: Van Den Mooter
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D000284:Administration, Oral; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage / Q000737:chemistry* / Q000378:metabolism; D003692:Delayed-Action Preparations; D004008:Diclofenac / Q000008:administration & dosage / Q000737:chemistry* / Q000378:metabolism; D004337:Drug Carriers; D016503:Drug Delivery Systems; D006863:Hydrogen-Ion Concentration; D015394:Molecular Structure; D011108:Polymers / Q000737:chemistry; D011109:Polymethacrylic Acids / Q000737:chemistry*; D012995:Solubility; D055672:Static Electricity; D044366:Transition Temperature
chemical_list: D000180:Acrylic Resins; D000894:Anti-Inflammatory Agents, Non-Steroidal; D003692:Delayed-Action Preparations; D004337:Drug Carriers; C446821:Eudragit L100-55; D011108:Polymers; D011109:Polymethacrylic Acids; D004008:Diclofenac; C518398:Eudragit E PO