APD-405

To assess the efficacy and safety of different doses of APD405 in the prevention of post-operative nausea and vomiting (PONV) in adult patients at moderate to high-risk of PONV. Patients must be undergoing elective surgery under general anaesthesia (hysterectomy (any surgical technique), cholecystectomy (any surgical technique) or "other" elective surgery scheduled to last at least one hour from induction of anaesthesia), requiring at least one overnight stay in hospital, and have at least 2 of the following risk factors for PONV: Past history of PONV and/or motion sickness; Non-smoking status; Female gender; Planned opiate use for post-operative analgesia.