Modified gums: Approaches and applications in drug delivery

Gums are naturally occurring components in plants, which are essentially cheap and plentiful. They have diverse applications as thickeners, emulsifiers, viscosifiers, sweeteners etc. in confectionary, and as binders and drug release modifiers in pharmaceutical dosage forms. However, most of the gums in their putative form are required in very high concentrations to successfully function as drug release modifiers in dosage forms due to their high swellability/solubility at acidic pH. Hence, gums need to be modified to alter their physicochemical properties. This article is aimed at discussing the modification of gums through derivatisation of functional groups, grafting with polymers, cross-linking with ions etc. The factors influencing these processes in the pursuit of making them suitable for modifying the drug release properties of pharmaceutical dosage forms and for other purposes is discussed with respect to optimization of their performance. (C) 2010 Elsevier Ltd. All rights reserved.