Study of a Novel Subcutaneous Depot Formulation of Buprenorphine

Inclusion Criteria: 1. Healthy males or non-pregnant, non-lactating females 2. Body mass index of 18.0-33.0 kg/m2 or, if outside the range, considered not clinically significant by the Investigator 3. Willing and able to communicate and participate in the whole study 4. Provide written informed consent prior to any study specific procedures 5. Good state of health (mentally and physically) as indicated by a comprehensive clinical assessment, ECG, and laboratory investigations 6. Males and females must agree to use an adequate method of contraception 7. Tolerated SL buprenorphine and nalorex during Period 1 Exclusion Criteria: 1. Medical history of opioid-related adverse reactions 2. History of clinically significant alcohol/drug abuse in the previous 5 years 3. Received any investigational medicinal product within the previous 3 months 4. Study site employees or immediate family members of study site or sponsor employee 5. Previously enrolled in the study 6. Regular alcohol consumption in males greater than 21 units/week and females greater than 14 units/week 7. Current smokers and those who have smoked within the last 6 months 8. Current users of e-cigarettes and nicotine replacement products and those who have used these products within the last 6 months 9. Do not have suitable veins for multiple venipunctures 10. Clinically significant abnormal biochemistry, haematology or urinalysis 11. Positive urine drug screen at screening and admission for each period 12. Positive hepatitis B surface antigen, hepatitis C virus antibody or human immunodeficiency virus results 13. History of clinically significant neurological, cardiovascular, renal, hepatic, chronic respiratory, or gastrointestinal disease, or psychiatric disorder 14. Serious adverse reaction or serious hypersensitivity to any drug or the formulation excipients 15. Clinically significant allergy requiring treatment. Hayfever is allowed unless active 16. Donation or loss of greater than 400 mL of blood within the previous 3 months 17. Taking or have taken, any prescribed or over-the counter drugs or herbal remedies in the 14 days before IMP administrations. Exceptions may apply 18. Injection sites containing any skin discolouration, tattoo, scar tissue or other abnormalities that may impair injection site assessment 19. Any food or drink containing grapefruit or Seville oranges within 7 days prior to first dose of buprenorphine 20. Treatment with any known drugs that are moderate or strong inhibitors/inducers of cytochrome P450 (CYP) 3A4 and/or cytochrome 450 2C8 enzyme within 30 days prior to first dose of study drug 21. Clinically significant abnormal ECG, including QT interval corrected using Fridericia's formula of greater than 450msec in males and greater than 470 msec in females