AUTHOR= Frontiers in Pharmacology Editorial Office TITLE=Expression of Concern: Water hyacinth: a possible alternative rate retarding natural polymer used in sustained release tablet design JOURNAL=Frontiers in Pharmacology VOLUME=7 YEAR=2016 URL=https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2016.00062 DOI=10.3389/fphar.2016.00062 ISSN=1663-9812