Palatability evaluation of orally disintegrating tablets using a visual analog scale in clinical trials

Visual analog scale (VAS) can be used to evaluate multiple parameters. There have been no reports on the verification of order effects or reproducibility of the VAS method for overall palatability of oral dosage forms. The purpose of this study was to assess the validity of a method for evaluating the palatability of orally disintegrating tablets (ODTs) using a 100-mm VAS.

We conducted clinical trials to evaluate the overall palatability, taste, and scent of 3 ODTs (F1, F2, F3) that contained famotidine (20, 10, and 5 mg, respectively). The study protocol was approved by the Research Ethics Committee of the University of Shizuoka, Japan (No. 21 - 36). To investigate the intergroup reproducibility of the VAS evaluation, 40 participants were divided into three groups, and each group underwent human gustatory sensation test of F1, F2, and F3, performed using a crossover design with 6 different tasting sequences. To evaluate intragroup reproducibility of the VAS evaluation, the participants assessed the same ODTs twice.

The VAS scores for overall palatability followed the same order (F3>F2>F1) in all groups. The VAS scores for the overall palatability of F1, F2, and F3 did not significantly differ between the first and second evaluations. The Kruskal-Wallis test indicated a minimal impact of the assessment order on ODT evaluations. We confirm the reliability and reproducibility of the VAS method for evaluating ODT palatability.

The VAS method for assessing ODT palatability provides accurate information and can contribute to the design and manufacture of patient-friendly pharmaceutical products.