Study to Assess Pharmacokinetic (PK), Bioavailability & Food Effect of MR902 Compared With Immediate Release (IR) Morphine Sulphate Oral Solution

Inclusion Criteria: * Healthy and free of significant abnormal findings as determined by medical history, physical examination, vital signs, laboratory tests and ECG. * Body weight ranging from 55 to 100 kg and a BMI ≥ 18.5 and ≤ 30.0. * Willing to eat all the food supplied throughout the study. * The subject's primary care physician has confirmed within the last 12 months of first dosing that there is nothing in their medical history that would preclude their enrolment into a clinical study. Exclusion Criteria: * Female subjects who are pregnant or lactating. * Any history of drug or alcohol abuse, misuse, physical or psychological dependence. * Any history of conditions that might interfere with drug absorption, distribution, metabolism or excretion. * Use of opioid or opioid antagonist-containing medication in the past 30 days. * Any history of frequent nausea or vomiting regardless of etiology. * Any history of seizures or symptomatic head trauma. * History of respiratory depression, hypoxia or elevated carbon dioxide levels in the blood. * History of paralytic ileus, gastrointestinal disease or other clinically significant gastrointestinal problems. * Participation in a clinical drug study during the 90 days preceding the initial dose in this study. * Any significant illness during the 4 weeks preceding entry into this study. * Use of any medication including vitamins, herbal and/or mineral supplements during the 7 days preceding the initial dose or during the course of this study (with the exception of the continued use of HRT and contraceptives). * History of smoking within 60 days of IMP administration and refusal to abstain from smoking during the study.