The primary objective of this study is to determine the pharmacokinetic and pharmacodynamic relationship of a single dose of fentanyl sublingual spray in opioid naive subjects. The secondary objective is to determine the safety and tolerability of fentanyl sublingual spray in opioid naive subjects.

Inclusion Criteria:

• Meets protocol-specified criteria for qualification and contraception
• Willing and able to remain confined in the study unit for the entire duration of each treatment period and comply with restrictions related food, drink and medications
• Voluntarily consents to participate and provides written informed consent prior to any protocol-specific procedures

Exclusion Criteria:

• History or current use of over-the-counter medications, dietary supplements, or drugs (including nicotine and alcohol) outside protocol-specified parameters

• Signs, symptoms or history of any condition that, per protocol or in the opinion of the investigator, might compromise:

  1. the safety or well-being of the participant or study staff
  2. the safety or well-being of the participant's offspring (such as through pregnancy or breast-feeding)
  3. the analysis of results