A Study to Determine the Fasting Bioequivalence of Reformulated OXY Tablets and Original OxyContin® (OXY) Tablets

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.