The primary objective of this study is to evaluate the analgesic efficacy, on Post-Operative Day (POD) 1, of DEX-IN compared with placebo, using the summed pain intensity difference over the first 48 hours (SPID48) in subjects with acute moderate to severe pain following unilateral bunionectomy.

Inclusion Criteria:

• Voluntarily provide written informed consent.

• Male or female between 18 and 70 years of age, inclusive.

• Be scheduled to undergo a primary unilateral first metatarsal bunionectomy repair

• Be American Society of Anesthesiology (ASA) physical class 1 or 2.

• Female subject are eligible only if all the following apply:

  • Not pregnant;
  • Not lactating;
  • Not planning to become pregnant during the study;
  • Be surgically sterile; or at least two year post menopausal; or have a monogamous partner who is surgically sterile; or is practicing double-barrier contraception; or practicing abstinence; or using an insertable, injectable, transdermal, or combination oral contraceptive.

• Male subjects must be surgically sterile or commit to the use of a reliable method of birth control

• Have a body mass index ≤35 kg/m2

• Be able to understand the study procedures, comply with all study procedures, and agree to participate in the study program.

Exclusion Criteria:

• Have a known allergy to dexmedetomidine or any excipient in DEX-IN/placebo or to any peri- or postoperative medications used in this study.
• Have a clinically significant abnormal clinical laboratory test value.
• Have history of or positive test results for HIV, or hepatitis B or C.
• Have a history or clinical manifestations of significant renal, hepatic, cardiovascular, metabolic, neurologic, psychiatric, or other condition that would preclude participation in the study.
• Have a history of migraine or frequent headaches, seizures, or are currently taking anticonvulsants.
• Have another painful physical condition that may confound the assessments of post operative pain.
• Have a history of syncope or other syncopal attacks.
• Have evidence of a clinically significant 12 lead ECG abnormality.
• Have a history of alcohol abuse (regularly drinks > 4 units of alcohol per day; 8 oz. beer, 3 oz. wine, 1 oz. spirits) or prescription/illicit drug abuse..
• Have positive results on the urine drug screen or alcohol breath test indicative of illicit drug or alcohol abuse.
• Have a history or evidence of orthostatic hypotension.
• Have a resting heart rate of <50 beats per minutes or systolic blood pressure <100mmHg.
• Have been receiving or have received chronic opioid therapy defined as greater than 15 morphine equivalents units per day for greater than 3 out of 7 days per week over a one-month period within 12 months.
• Use concurrent therapy that could interfere with the evaluation of efficacy or safety, such as any drugs which in the investigator's opinion may exert significant analgesic properties or act synergistically with DEX-IN.
• Unable to discontinue medications, that have not been at a stable dose for at least 14 days prior to the scheduled bunionectomy procedure, within 5 half lives of the specific prior medication (or, if half life is not known, within 48 hours) before dosing.
• Have utilized any intranasal medications within the preceding 10 days.
• Have signs or a history of significant rhinitis or rhinorrhea (constant or chronic), nasal polyps, mucosal lesions of the nostril, postnasal drip of any etiology (constant or chronic), nasal ulcers, septal perforation or deviation, any nasal surgery, anosmia, nasal piercings, or frequent nosebleeds or other nasal pathology, that is sufficient to interfere with IN drug delivery.
• Have had an upper respiratory tract infection within 14 days of screening.
• Have utilized corticosteroids, either systemically, inhalational either intranasally or oral, or by intra-articular injection, within 14 days prior to the study.
• Have received any investigational product within 30 days before dosing with study medication.
• Have previously received DEX-IN in clinical trials, or had bunionectomy in the last 3 months.

Safety analysis set - All subjects receiving at least one study dose

All AEs were collected through the Day 7 study visit. All SAEs were assessed through the Day 7 visit, but were reported through 30 days of the last study visit if the investigator was made aware of the event.