To assess the relative bioavailability of varenicline administered intranasally at its highest intended clinical strength compared to varenicline administered orally at its highest oral tablet strength.

This study was a Phase 1, open-label, randomized, 2-way crossover study to evaluate the relative bioavailability of OC-01 (varenicline) Nasal Spray compared to varenicline administered orally as varenicline oral tablet. Approximately 22 healthy volunteer subjects between 18-65 years of age meeting all other study eligibility criteria were randomized (Treatment Period 1) to receive an intranasal dose of 0.12 mg OC-01 (50 µL spray of 0.06 mg into each nostril) or a single 1 mg oral dose of varenicline oral tablet. Both administrations were delivered while subject is in an overnight fasted state. Subjects then returned at least 14 days later (Treatment Period 2) to receive the alternate dose of varenicline that was delivered at Treatment Period 1. Again, this delivery was performed while subject was in an overnight fasted state.

Participants who terminated early during the application period were asked to complete safety assessments (if the participants agree) prior to study exit. Participants who were terminated early from the study were not replaced.

Inclusion Criteria:

• Body mass index between 18.0 and 32.0 kg/m2, inclusive.
• Healthy as determined by a responsible and experienced physician, based on a medical evaluation including medical history, physical examination, ECG and laboratory tests.
• Have provided verbal and written informed consent
• If a female of childbearing potential who is not using an acceptable means of birth control (acceptable methods of contraception include: hormonal - oral, implantable, injectable, or transdermal contraceptives, mechanical - spermicide in conjunction with a barrier such as a diaphragm or condom, IUD, or surgical sterilization of partner), have a negative urine pregnancy test at the Screening Visit.

Exclusion Criteria:

• Have had nasal or sinus surgery (including history of application of nasal cautery) or significant trauma to these areas.
• Have a vascularized polyp, severely deviated septum, chronic recurrent nosebleeds, or severe nasal airway obstruction as confirmed by intranasal examination at the Screening Visit.
• Any contraindication to varenicline according to the applicable label.
• Have severe renal impairment (estimated creatinine clearance less than 30mL per minute)
• Have current concomitant use of snuff, chewing tobacco, e-cigarettes or cigarettes/cigars during the study
• Have any condition or history that, in the opinion of the investigator, may interfere with study compliance, outcome measures, safety parameters, and/or the general medical condition of the subject
• Be a female who is pregnant, nursing an infant, or planning a pregnancy at the Screening Visit. Be a woman of childbearing potential who is not using an acceptable means of birth control; acceptable methods of contraception include: hormonal - oral, implantable, injectable, or transdermal contraceptives; mechanical - spermicide in conjunction with a barrier such as a diaphragm or condom; IUD; or surgical sterilization of partner.
• Be currently enrolled in an investigational drug or device study or have used an investigational drug or device within 30 days prior to the Screening Visit.