The purpose of this study is to assess the bioequivalence of a new oxycodone formulation (80 mg) relative to the original OxyContin® (OXY) formulation (80 mg) in the fasted state.

Oxycodone hydrochloride (oxycodone) is a semi-synthetic opioid analgesic that is effective in the relief of moderate to severe malignant and non-malignant pain.

Inclusion Criteria:

• Males and females aged 18 to 50, inclusive.
• Body weight ranging from 50 to 100 kilograms (kg) and a body mass index (BMI) ≥18 and ≤34 (kg/m2).
• Healthy and free of significant abnormal findings as determined by medical history, physical examination, vital signs, and electrocardiogram (ECG).
• Females of child-bearing potential must be using an adequate and reliable method of contraception.
• Willing to eat all the food supplied during the study.

Exclusion Criteria:

• Females who are pregnant or lactating.
• Any history of or current drug or alcohol abuse for 5 years.
• History of or any current conditions that might interfere with drug absorption, distribution, metabolism or excretion.
• Use of an opioid-containing medication in the past 30 days.
• History of known sensitivity to oxycodone, naltrexone, or related compounds.
• Any history of frequent nausea or emesis regardless of etiology.
• Any history of seizures or head trauma with current sequelae.
• Participation in a clinical drug study during the 30 days preceding the initial dose in this study.
• Any significant illness during the 30 days preceding the initial dose in this study.
• Use of any medication including thyroid hormone replacement therapy (hormonal contraception is allowed), vitamins, herbal, and/or mineral supplements, during the 7 days preceding the initial dose.
• Refusal to abstain from food for 4 hours following administration of the study drugs and to abstain from caffeine or xanthine entirely during each confinement.
• Consumption of alcoholic beverages within forty-eight (48) hours of initial study drug administration (Day 1) or anytime following initial study drug administration.
• History of smoking or use of nicotine products within 45 days of study drug administration or a positive urine cotinine test.
• Blood or blood products donated within 30 days prior to administration of the study drugs or anytime during the study, except as required by this protocol.
• Positive results for urine drug screen or alcohol screen at Check-in of each period, and hepatitis B surface antigen (HBsAg), hepatitis B surface antibody (HBsAb) (unless immunized), anti-hepatitis C antibody (HCV).
• Positive Naloxone hydrochloride (HCl) challenge test.
• Presence of Gilbert's Syndrome or any known hepatobiliary abnormalities.

Ongoing AEs-followed until resolution/30 days after last dose;AEs reported during 7 days following last dose were recorded & followed until resolution or up to 30 days after last dose. All SAEs were followed until resolution or event/sequelae stabilized.

AEs were collected through spontaneous reports, subject interview, or subject diaries.