Study design
The purpose of this single-blind, placebo-controlled, crossover study is to evaluate the efficacy of D-sorbitol in masking the bitter taste of sublingual asenapine tablets. D-Sorbitol oral solution 75% (KOWA, Aichi, Japan) will be used as the test solution in this study. The dosing period will be 1 day each in study periods ① and ②. Taste evaluations will be performed at home for outpatients and during hospitalization for inpatients, with a 1-day test interval to eliminate the carryover effect of D-sorbitol. Patients will be given an oral rinse with D-sorbitol or a placebo solution before taking the sublingual asenapine tablets. Then, after a 1-day interval, the patients will rinse their mouths again with a different liquid than that used on day 1. A questionnaire survey regarding taste evaluations and the intention to continue asenapine with the intervention will be conducted on the participants before the start of the study and after each rinse.