title: Unpredictable Performance of pH-Dependent Coatings Accentuates the Need for Improved Predictive in Vitro Test Systems.
abstract: First introduced in the second half of the 19th century, enteric coatings are commonly used to protect acid-labile drugs, reduce the risk of gastric side effects due to irritating drugs, or for local drug delivery to the lower gastrointestinal (GI) tract. The currently available enteric-coatings are based on pH-sensitive weakly acidic polymers. Despite the long history of their use, the causes behind their performance often being unpredictable have not been properly investigated with most of the attention being focused only on the gastric emptying. However, little attention has been given to the postgastric emptying disintegration and dissolution of these dosage forms. This lack of attention has contributed to the difficulty in predicting the in vivo behavior of these dosage forms and to cases of bioavailability problems with some enteric-coated products. Therefore, increased attention needs to be given to this issue.
authors.affiliation: Institute of Pharmacy and Biochemistry, Johannes Gutenberg University Mainz , Staudinger Weg 5, 55099 Mainz, Germany.
authors.forename: Jozef
authors.initials: J
authors.lastname: Al-Gousous
authors.affiliation: Department of Pharmaceutical Sciences, University of Michigan , Ann Arbor, Michigan 48109, United States.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Tsume
authors.affiliation: Institute of Pharmacy and Biochemistry, Johannes Gutenberg University Mainz , Staudinger Weg 5, 55099 Mainz, Germany.
authors.forename: Maoqi
authors.initials: M
authors.lastname: Fu
authors.affiliation: International Pharmaceutical Research Center , 1 Queen Rania Street, Amman 11196, Jordan.
authors.forename: Isam I
authors.initials: II
authors.lastname: Salem
authors.affiliation: Institute of Pharmacy and Biochemistry, Johannes Gutenberg University Mainz , Staudinger Weg 5, 55099 Mainz, Germany.
authors.forename: Peter
authors.identifier: 0000-0003-3758-7581
authors.initials: P
authors.lastname: Langguth
mesh_terms: D001682:Biological Availability; D001702:Biopharmaceutics; D002626:Chemistry, Pharmaceutical; D065546:Drug Liberation; D005079:Excipients / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques / Q000379:methods*; D007421:Intestine, Small / Q000378:metabolism*; D012995:Solubility; D013608:Tablets, Enteric-Coated / Q000737:chemistry*
chemical_list: D005079:Excipients; D013608:Tablets, Enteric-Coated
keywords: biorelevant; disintegration; dissolution; enteric-coating; pH-sensitive polymer