TIMERx: novel polysaccharide composites for controlled/programmed release of drugs in the gastrointestinal tract.

Over the last 100 years tablets have grown from first invention to becoming the world's leading medicinal form, by any measure. This article considers some of the reasons for the pre-eminence of pharmaceutical tablets. Particular attention has been given to the role of controlled-release tablets and to a very versatile hydrogel-based controlled-release technology, called TIMERx((R)). The unique nature of TIMERx intermolecular physical chemistry is described in relation to the technology's potential to provide any one of a number of different release profiles, ranging from zero order to chronotherapeutic release. The unusual nature of TIMERx technology lies in its ability to provide different release kinetics by the manipulation of molecular interactions. This 'molecular engine' replaces the need for complex processing or novel excipients and allows desired drug release profiles to be 'factory set' following a simple formulation development process. The article describes the physico-chemical interactions of TIMERx technology at a molecular level and how they can be manipulated by formulation considerations. The article describes how TIMERx technology has been developed to the point where today it underpins a number of marketed pharmaceutical CR products as well as products under development by Penwest Pharmaceuticals.