Inclusion Criteria:  Must understand and provide written informed consent prior to the initiation of any protocol-specific procedures. Males and females 18 to 55 years of age, inclusive. Body mass index (BMI) ranging from 18 to 34 kg/m2, inclusive, and body weight of 56 kg and above. Adequate venous access as assessed by an investigator at screening. No clinically significant concurrent medical conditions determined by medical history, physical examination, clinical laboratory examination, vital signs, and 12-lead ECG. Recreational opioid use (i.e., defined as prescription opioid use for nontherapeutic purposes on at least 3 occasions within the previous year and at least once in the 12 weeks prior to screening), experienced in using opioids of approximately 30 mg morphine equivalents and not seeking treatment for Opioid Use Disorder.  If of childbearing potential, a female study subject must agree to use 1 of the accepted contraceptive regimens from at least 30 days prior to the first administration of the study medication, during the study and for at least 30 days after the last dose of the study medication  An acceptable method of contraception includes abstinence from heterosexual intercourse or intrauterine device (with or without hormones) OR agrees to use a double barrier method (e.g., condom and spermicide) during the study and for at least 30 days after the last dose of the study medication. Oral contraceptives are prohibited. If a female of non-childbearing potential, she should be surgically sterile (i.e., has undergone compete hysterectomy, bilateral oophorectomy, or tubal ligation) or in a menopausal state (at least 1 year without menses), as confirmed by FSH level. A male study subject must agree to use a double barrier method (e.g., condom and spermicide) and agree to not donate sperm during the study and for at least 90 days after the last dose of the study medication. Agree not to ingest alcohol, drinks containing caffeine >500 mg/day (e.g., Coca Cola®, tea, coffee, etc.), or grapefruit/grapefruit juice or participate in strenuous exercise 72 hours prior to admission through the last blood draw of the study. Able to speak, read, and understand English sufficiently to allow completion of all study assessments. Must be willing and able to abide by all study requirements and restrictions.  Exclusion Criteria:  Contact site directly for more information