Swelling agents and devices in oral drug delivery

Swelling agents are hydrophilic crosslinked polymers, which swell from 10 to 1,000 times their own weight when placed in an aqueous medium. Depending on their swelling properties, these materials have been exploited in developing three different classes of materials in pharmaceutical industries, i.e. swellable matrices, superdisintegrants and swelling devices. Since their development, these pharmaceutical excipients have found significant applications in drug delivery area. This review examines the properties of swelling agents and devices with the focus on drug delivery applications.