Sensory attributes of coated tablets: developing a formal lexicon and sensory wheel

The patient's sensory experience when taking an oral medicine is important in the assessment of its palatability, and acceptability. The aim of this study was to develop tools useful for standardisation of sensory assessment of coated tablets: a lexicon and a sensory wheel. Two randomised, double-blind sensory assessments were performed involving 83 and 52 heathy adult volunteers and two sets of coated tablets. By adapting the principles used by food sciences, a free-text description of conventional, bitter-tasting or tasteless, coated tablets was performed. In the first assessment, volunteers described the sensory attributes of the first set of tablets. The attributes collected were then validated using a second set of tablets in a separate study with different volunteers. The appropriateness and semantics of each sensory attribute was analysed. Twenty attributes most relevant for assessment of coated tablets were selected for the lexicon and associated with explicit definitions. A collection of all attributes that could possibly be triggered by coated tablets were organised in the form of a sensory wheel. This study provides a valuable insight into the sensory experience while taking a coated tablet and presents tools which can accelerate the development of palatable medicines.