Modified Starches as Direct Compression Excipients – Effect of Physical and Chemical Modifications on Tablet Properties: A Review

Abstract

Starch is an abundant natural polymer with unique properties that make it amenable to various kinds of treatments. This deliberate attempt at altering the character of native starch results in modified starches. Starches are extensively used in the pharmaceutical industry, especially as excipients in tablet formulation. It is now widely acknowledged that starches in their native form have functional limitations. Modification is a means of enhancing the functionality of native starch for a wide variety of applications. The importance of modified starches as excipients for pharmaceutical direct compression has been identified. Although, there is a wealth of information on starch modification, characterization and applications in the literature, there does not appear to be as yet, any attempt at a methodological analysis of physical and chemical modification techniques as they apply to pharmaceutical direct compression. This review aims at addressing these gaps. It describes a range of physical and chemical techniques employed in producing modified starches and their potentials as excipients for direct compression. The effect of modification on the morphological and functional properties of starch in various direct compression formulations is also reviewed.