 Participants will be evaluated during screening 24 hours before Study Day 1 and on Study Days 1-5, 14 and 28. Participants will be confined in the SingHealth Investigational Medicine Unit IMU from screening until end of study assessments on Study Day 5 and return to the clinic at Day 14 and 28 as outpatients. All patients will receive capsules Q6H for 5 days prepared by an open-label pharmacist according to the randomisation plan. 