title: Development of a bionic system for the simultaneous prediction of the release/absorption characteristics of enteric-coated formulations.
abstract: OBJECTIVE
  To develop a new bionic system from an existing drug dissolution/absorption simulating system (DDASS) to simultaneously predict the release and absorption of enteric-coated formulations.
  
  
  METHODS
  In accordance with the pH-dependent characteristics of enteric-coated formulations, the modified DDASS was designed to effectively imitate the pH change process of the formulations' transfer from stomach to intestine in vivo. Omeprazole enteric-coated tablets were chosen as the model drug to verify the rationality and feasibility of the modified DDASS. The correlations between USP I system release and beagle dog absorption, as well as between modified DDASS elution/permeation and beagle dog absorption, were investigated by linear and nonlinear regression analyses, respectively.
  
  
  RESULTS
  In vitro-in vivo correlation between the modified DDASS elution/permeation method and beagle dog absorption was higher than between the USP I system release and beagle dog absorption in both analytical methods. The ratio of first-order permeation rate constant to first-order release rate constant was consistent with that from modified DDASS.
  
  
  CONCLUSIONS
  The modified DDASS provided more information than the USP I system did in the evaluation of enteric-coated formulations. The proposed bionic system model could serve as a new method for improving drug effectiveness.
authors.affiliation: Tianjin University of Traditional Chinese Medicine Tianjin State Key Laboratory of Modern Chinese Medicine, Tianjin, China.
authors.forename: Weijun
authors.initials: W
authors.lastname: Liu
authors.forename: Xin
authors.initials: X
authors.lastname: He
authors.forename: Ziqiang
authors.initials: Z
authors.lastname: Li
authors.forename: Xiumei
authors.initials: X
authors.lastname: Gao
authors.forename: Yetao
authors.initials: Y
authors.lastname: Ma
authors.forename: Mingjin
authors.initials: M
authors.lastname: Xun
authors.forename: Changxiao
authors.initials: C
authors.lastname: Liu
mesh_terms: D000818:Animals; D000897:Anti-Ulcer Agents / Q000008:administration & dosage* / Q000737:chemistry / Q000493:pharmacokinetics*; D002626:Chemistry, Pharmaceutical / Q000295:instrumentation; D004285:Dogs; D004867:Equipment Design; D006863:Hydrogen-Ion Concentration; D016014:Linear Models; D008297:Male; D008954:Models, Biological; D009853:Omeprazole / Q000008:administration & dosage* / Q000737:chemistry / Q000493:pharmacokinetics*; D051381:Rats; D012995:Solubility; D013608:Tablets, Enteric-Coated
chemical_list: D000897:Anti-Ulcer Agents; D013608:Tablets, Enteric-Coated; D009853:Omeprazole