title: New evaluation method for in vitro/in vivo correlation of enteric-coated multiple unit dosage forms.
abstract: OBJECTIVE
  To establish the evaluating method for drug dissolution profiles in the gastrointestinal (GI) tract based on in vitro data for the enteric-coated multiple unit.
  
  
  METHODS
  Dissolution profile in the GI tract was calculated by the convolution procedure using an in vitro dissolution profile as a weighting function, and the gastric-emptying (GE) process as an input function (GE-convolution method). A computer program, GECONV, was developed for numerical execution of the convolution integral.
  
  
  RESULTS
  The in vivo dissolution profile of enteric-coated aspirin granules estimated by GE-convolution was in good agreement with the in vivo cumulative absorption profile calculated by the Wagner-Nelson method using the plasma concentration data after oral administration to healthy subjects. The in vitro/in vivo correlation improved markedly by taking the GE process into consideration.
  
  
  CONCLUSIONS
  These findings indicated that this convolution method is useful for estimating the in vivo dissolution profile of drugs, when they are administered in an enteric-coated multiple unit type dosage form, because the gastric emptying process is a determinant process for the in vivo drug dissolution.
authors.affiliation: Developmental Research Laboratories, Shionogi & Co., Ltd., Hyogo, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Hayashi
authors.forename: T
authors.initials: T
authors.lastname: Ogura
authors.forename: Y
authors.initials: Y
authors.lastname: Takagishi
mesh_terms: D000328:Adult; D001241:Aspirin / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics; D004304:Dosage Forms; D005069:Evaluation Studies as Topic; D005746:Gastric Emptying; D006801:Humans; D066298:In Vitro Techniques; D007408:Intestinal Absorption; D008297:Male; D008954:Models, Biological; D012984:Software; D013608:Tablets, Enteric-Coated / Q000493:pharmacokinetics*; D013810:Therapeutic Equivalency
chemical_list: D004304:Dosage Forms; D013608:Tablets, Enteric-Coated; D001241:Aspirin