The Sustained Release Coating of Solid Dosage Forms: A Historical Review

Abstract

The continued development of sustained release technology over the past forty years has provided countless ways of producing long acting dosage forms. Of all the methods proposed, coating has proven to be one of the most enduring. Although many have attempted to introduce new sustained release coatings to the marketplace, only three have been widely accepted. This paper seeks to provide the reader with a historical review of sustained release coating and examine the reasons why three materials, cellulose acetate, ethylcellulose and methacrylic acid copolymer have dominated this technology.