Particle properties: Impact on the processing and performance of oral extended-release hydrophilic matrix tablets

Abstract

The role of the particulate properties of the drug substance and the release rate controlling polymer in hydrophilic matrix extended release tablets, principally those based on hydroxypropyl methylcellulose, are reviewed. The effect on drug release of drug particle size and how this interacts with drug solubility properties are considered and also how control of particle size and amount of polymer together are key to producing robust products with a desired, reliable rate of drug release. The utility of the recently introduced direct compression grade hydroxypropyl methylcellulose is described and observations as to the triboelectric properties of the cellulose ether are given.