Study to Determine Efficacy and Safety of Inhaled AeroLEF in the Treatment of Acute Post-op Pain in Adult Patients Undergoing Elective Orthopedic Surgery

Inclusion Criteria: male and female 18 to 70 years patient alert and capable of self-administering an opioid anaglesic Patient is scheduled for orthopedic surgery under general anesthesia Patient has normal laboratory values Physical examination with no clincially relevant findings Patient in general good health based on medical history and clincially acceptable Patient is able to understand the requirements of the study Patient is able to communicate effectively with study personnel _Patient voluntarily gives written approval. Exclusion Criteria: During Part 2 (randomized period) which involves the use of placebo, patients who are undergoing a major orthopedic procedure that normally requires multimodal analgesia to achieve adequate postoperative pain control (e.g. major spine surgery, total knee arthoplasty) will be excluded. Patient is taking opioid or non-opioid analgesics on a chronic basis at doses which in the opinion of the investigator would interfere with evaluations of post-operative fentanyl efficacy. History of pulmonary, cardiovascular, neurologic, endocrine, hepatic, gastrointestinal (GI), or kidney disease or therapy that would jeopardize the patient's well-being by participation in this study. Patient has documented or self-reported medical history of sleep apnea. Patient has a documented hypersensitivity to fentanyl or other opioid analgesics. Patient has a documented hypersensitivity/allergy to the components of the liposomes used in the AeroLEF formulation, including hypersensitivity to soya lecithin or related food products such as soya bean and peanut. Patient is currently receiving treatment, or has received treatment in the previous two weeks, with monoamine oxidase inhibitors. Patient has a history of malignancy within the past 5 years, with the exception of successfully treated non?metastatic basal cell or squamous cell carcinomas of the skin and/or localized carcinoma in situ of the cervix. Patient was dosed with another investigational drug within 30 days prior to the Screening Visit. Patient has current therapy with CNS-depressant medications (other than stable doses of analgesics and drugs used with surgical anesthesia). Patient has current evidence of alcohol abuse (regularly drinks more than 4 units of alcohol per day; 1 unit = ½ pint of beer, 1 glass of wine, or 1 ounce of spirit). Patient has a history of abuse of licit or illicit drug substances. Patient, who in the opinion of the Investigator, is mentally or emotionally unsuitable to participate, or unable/unwilling to comply with the study assessments.