A review on the taste masking of bitter APIs: hot-melt extrusion (HME) evaluation

Abstract
The majority of active pharmaceutical ingredients (APIs) found in oral dosage forms have a bitter taste. Masking the unpleasant taste of bitter, APIs is a major challenge in the development of such oral dosage forms. Taste assessment is an important quality-control parameter for evaluating taste-masked formulations of any new molecular entity. Hot-melt extrusion (HME) techniques, have very recently, been accepted from an industrial compliance viewpoint in relation to both manufacturing operations and development of pharmaceuticals. HME achieves taste masking of bitter APIs via various mechanisms such as the formation of solid dispersions and inter-molecular interactions and this has led to its wide-spread use in pharmaceutical formulation research. In this article, the uses of various taste evaluation methods and HME as continuous processing techniques for taste masking of bitter APIs used for the oral delivery of drugs are reviewed.