Application of an electronic nose system for evaluation of unpleasant odor in coated tablets.

The purpose of this study was to apply an electronic nose system for evaluation of unpleasant odor in tablets containing L-cysteine, an unpleasant odor drug, and demonstrate the odor masking ability of thin-layer sugarless coated tablets, which we have newly developed, by both electronic nose system and sensory evaluations. We demonstrated the qualitative evaluation of the unpleasant odor using air as a reference indicator and the quantitative evaluation of the unpleasant odor using the distances between air and samples in the electronic nose system evaluation. The electronic nose system evaluation was positively and well-correlated with the sensory evaluation by volunteers. We suggest that the electronic nose system evaluation is appropriate as an alternative or a support method for sensory evaluation by volunteers. As the results of both electronic nose system and sensory evaluations, we demonstrated that the thin-layer sugarless coated tablets have excellent masking ability of the unpleasant odor, equivalent to that of sugar-coated tablets due to the dense coating layers.