Study to Investigate the Safety, Tolerability and Pharmacokinetics of QEV-817 Oral Suspension

Key Inclusion Criteria - include but are not limited to: * Male or female aged 18-55 years, inclusive, on the day of screening. * Willing to abstain from alcohol and strenuous physical activity (i.e., strenuous, or unaccustomed weightlifting, running, bicycling, etc.) from 48 hours prior to study treatment administration until discharge from the clinical unit and prior to each outpatient visit. * Have normal laboratory values, as defined per protocol, at screening. * Absence of cardiac arrythmias, as well as corrected QT interval (QTc) \< 450 ms in males and QTc \< 460 ms in females based on 12-lead ECG findings at screening. * Body weight ≥50 kg and body mass index (BMI) within the range of 19-32 kg/m2 (inclusive). * Has never used opioids for non-therapeutic purposes (i.e., for recreational effects). Subjects with a history of valid medical use under prescription must have not used an opioid for at least three (3) months prior to Day 1. * Women of childbearing potential (WOCBP), as defined in Section 10.4, must have a negative serum pregnancy test within one (1) week AND a negative urine pregnancy test on Day 2, prior to the start of study treatment; Must not be breastfeeding, lactating, or planning a pregnancy during the study and for at least 32 days (5 half-lives plus 30-days) after the last dose of study intervention * Postmenopausal females must have a documented serum follicle-stimulating hormone (FSH) level \>40 mIU/mL (milli international units per milliliter) at s…