A Pharmacokinetic, Safety and Tolerability Study in Healthy Adult Males

Inclusion Criteria:

• Healthy as determined by a responsible physician or trained qualified designee
• Males: 18 - 55 years inclusive at screening
• Capable of giving written informed consent

Exclusion Criteria:

• Clinically significant conditions or history of fainting or syncope
• Medical or psychiatric illness that could interfere with the completion of treatment and follow up
• Major surgery within 4-weeks of screening
• Known difficulty with obtaining intravenous access
• History of sensitivity to the study medication, or intolerance to opioids, or a history of medication or other allergy that contraindicates their participation
• Use of prescription or non-prescription medications
• History of excessive alcohol use
• History of drug abuse within 6 months of screening
• Use of any illegal drug within 30 days of screening and throughout participation in the study
• History of smoking or use of nicotine containing products within 3 months of screening and throughout participation in the study
• Donation of blood or plasma 4 weeks prior to dosing
• Participation in a clinical trial and has received medication within 30 days
• Weight <50 kg or BMI outside range of 18-32 kg/m2
• Positive for HIV antibody, hepatitis B virus surface antigen, or hepatitis C virus
• Unwillingness to abstain from sexual intercourse with a pregnant or lactating woman and, if engaging in sexual intercourse with a female partner of child-bearing potential, use a condom and spermicide, in addition to having their female partner use another form of contraception, and abstain from sperm donation