title: Floating and sustained-release characteristics of effervescent tablets prepared with a mixed matrix of Eudragit L-100-55 and Eudragit E PO.
abstract: The aim of this study was to evaluate the influence of Na-bicarbonate as an effervescent agent on the floating and sustained-release characteristics in 0.1 M HCl of tablets made of Eudragit E PO (EE) and/or Eudragit L-100-55 (EL) as matrix formers at different EE:EL weight ratios: 0:100, 25:75, 50:50, 75:25, and 100:0. The tablets were made by direct compression utilizing metronidazole as a model drug. Effervescent tablets with 50EE/50EL (w/w) showed the best floating and sustained drug release properties in the dissolution medium. The corresponding noneffervescent tablets were nonfloating and showed significantly faster drug release. Effervescent tablets with single polymers showed an immediate drug release pattern. These results were explained by Fourier-transform infrared spectroscopy and elemental analysis, which showed strong evidence of interpolyelectrolyte complexation between EE and EL when they were exposed to 0.1 M HCl as an effervescent hybrid matrix, but not as a noneffervescent hybrid matrix. The role of Na-bicarbonate in allowing EE-EL complexation during dissolution was explained as due to raising the pH around EL particles for sufficient polymer ionization and ionic-interaction with the ionized EE.
authors.affiliation: Faculty of Pharmacy, The University of Jordan, Amman, Jordan. abjaber@ju.edu.jo
authors.forename: Ahmad Khaled
authors.initials: AK
authors.lastname: Bani-Jaber
authors.forename: Mahmoud Yousef
authors.initials: MY
authors.lastname: Alkawareek
authors.forename: Jozef Jawad
authors.initials: JJ
authors.lastname: Al-Gousous
authors.forename: Ahmad Yousef
authors.initials: AY
authors.lastname: Abu Helwa
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry* / Q000493:pharmacokinetics*; D002626:Chemistry, Pharmaceutical / Q000379:methods*; D003692:Delayed-Action Preparations / Q000737:chemistry / Q000493:pharmacokinetics; D011109:Polymethacrylic Acids / Q000737:chemistry* / Q000493:pharmacokinetics*; D013607:Tablets
chemical_list: D000180:Acrylic Resins; D003692:Delayed-Action Preparations; C446821:Eudragit L100-55; D011109:Polymethacrylic Acids; D013607:Tablets; C518398:Eudragit E PO