A system-approach-based method is proposed for modeling drug absorption fro
m enteric-coated granules. This method was e,exemplified using enteric-coat
ed granules of aspirin given to healthy subjects. Based on the results obta
ined, it can be concluded that absorption of salicylate from the granules c
an be sufficiently described using a first-order linear model with an absor
ption rate constant of salicylate similar to that reported for an aqueous s
olution of aspirin administered orally to healthy subjects. The method prop
osed in this study. may contribute to the working library of modeling techn
iques in pharmacokinetics since it allows direct modeling of the drug absor
ption process and estimates the absorption rate constant of a drug when its
behavior in the body is significantly influenced by a gastric emptying pro
cess, i.e., when the absorption rate constant of the drug cannot be estimat
ed on the basis of its cumulative absorption-time profile. (C) 2001 Prous S
cience. All right reserved.