Comparing tablet and capsule forms of KDT3594

Inclusion criteria: 1)Participants who personally provide written informed consent to participate in the clinical trial 2)At the time of informed consent, participants aged >=18 and ==18.5 to =50 to =45 to <90 kg Exclusion criteria: 1)Participants who have abnormal findings on medical examination, vital signs, or 12-lead ECG, which are considered clinically significant by the principal investigator or the subinvestigator 2)Male participants with a QTcF interval of >=450 msec or female participants with a QTcF interval of >=470 msec on a 12-lead ECG 3)Participants who have abnormal findings in the screening test or clinical laboratory tests on the day before KDT-3594 administration in Period I and are judged as clinically significant by the principal investigator or the subinvestigator 4)Participants who have experienced systolic blood pressure (standing) of =20 mmHg from the measurement in the supine position 5)Participants who tested positive for immunological tests (HBs antigen, HCV antibody, serologic test for syphilis, and HIV antigen/antibody) in the screening test 6)Participants who tested positive for the urine drug abuse test (phencyclidines, benzodiazepines, cocaine-based narcotics, stimulants, cannabis, morphine-based narcotics, barbiturates, and tricyclic antidepressants) in the screening test 7)Participants with a history of drug allergy 8)Participants with a history of repeated syncope or diagnosed cardiovascular or cerebrovascular abnormalities 9)Participants with a history or complication of orthostatic hypotension 10)Participants with a history of disease or surgery (e.g., gastrectomy and cholecystectomy) that may affect the absorption of the trial intervention 11)Regular drinkers consuming >40 g of pure alcohol per day on average 12)Participants who smoked cigarettes (including e-cigarettes) or consumed nicotine-containing products within 12 weeks before KDT-3594 administration in Period I 13)Participants who used other ethical drugs or OTC drugs (including vitamins or nutritional drinks) within 2 weeks before KDT-3594 administration in Period I (topical formulations not expecting systemic effects may be used) 14)Participants who took supplements known to affect pharmacokinetics (e.g., St. John's wort [Hypericum perforatum]) within 2 weeks before KDT-3594 administration in Period I 15)Participants who consumed grapefruit, orange, or food and drink containing grapefruit or orange within 1 week before KDT-3594 administration in Period I 16)Participants who have used a drug that alters the CYP3A or P-gp activity within 4 weeks (or >=5 times of the half-life, whichever is longer) before KDT-3594 administration in Period I 17)Participants who exercised excessively with fatigue or myalgia within 1 week before KDT-3594 administration in Period I 18)Participants who donated >400 mL of whole blood within 12 weeks, >200 mL of whole blood within 4 weeks, or any blood component within 2 weeks before KDT-3594 administration in Period I 19)Female participants who are pregnant, breastfeeding, planning to become pregnant during the study period, or who do not intend to use adequate contraception 20)Female participants with a positive pregnancy test at screening 21)Participants who received other trial interventions within 16 weeks before KDT-3594 administration in Period I (within 12 weeks for clinical trials of already approved drugs) 22)Participants previously treated with KDT-3594 23)Other participants judged as inappropriate for the trial by the principal investigator or subinvestigator