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