title: Interpolyelectrolyte complexes of Eudragit E PO with sodium alginate as potential carriers for colonic drug delivery: monitoring of structural transformation and composition changes during swellability and release evaluating.
abstract: BACKGROUND
  With a view to the application in oral colon drug delivery systems, swelling and release behavior of synthesized interpolyelectrolyte complexes (IPEC) between sodium alginate and Eudragit EPO were investigated.
  
  
  METHODS
  The microenvironmental changes in IPECs structure as a function of pH during swellability testing were investigated using FT-IR spectroscopy and elementary analysis.
  
  
  RESULTS
  All samples of IPECs (Z = 0.66-1.25) during swelling were transformed to a similar structure with approximately the same composition. The release of the model drug diclofenac sodium was significantly delayed from matrices made up of the IPECs and independent from the composition of polycomplexes.
  
  
  CONCLUSIONS
  According to the obtained results, these IPECs can be considered to have potential in colonic drug delivery as combined pH- and time-dependent systems.
authors.affiliation: Department of Pharmaceutical, Toxicological and Analytical Chemistry, State Medical University of Kazan, Kazan, Russian Federation. mustaf@rambler.ru
authors.forename: Rouslan I
authors.initials: RI
authors.lastname: Moustafine
authors.forename: Albina R
authors.initials: AR
authors.lastname: Salachova
authors.forename: Ekaterina S
authors.initials: ES
authors.lastname: Frolova
authors.forename: Vera A
authors.initials: VA
authors.lastname: Kemenova
authors.forename: Guy
authors.initials: G
authors.lastname: Van den Mooter
mesh_terms: D000464:Alginates / Q000737:chemistry*; D003106:Colon / Q000378:metabolism*; D004008:Diclofenac / Q000008:administration & dosage / Q000737:chemistry; D004337:Drug Carriers / Q000138:chemical synthesis / Q000737:chemistry*; D016503:Drug Delivery Systems / Q000379:methods*; D004573:Electrolytes / Q000737:chemistry*; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D008954:Models, Biological; D008968:Molecular Conformation; D011109:Polymethacrylic Acids / Q000737:chemistry*; D012995:Solubility; D017550:Spectroscopy, Fourier Transform Infrared; D013607:Tablets; D013997:Time Factors; D014867:Water / Q000032:analysis
chemical_list: D000464:Alginates; D004337:Drug Carriers; D004573:Electrolytes; D006603:Hexuronic Acids; D011109:Polymethacrylic Acids; D013607:Tablets; D014867:Water; D004008:Diclofenac; D020723:Glucuronic Acid; C518398:Eudragit E PO