The objective of this study was to compare the rate of absorption and bioavailability of fentanyl 400 µg sublingual spray, Actiq® 400 µg transmucosally, and fentanyl citrate injection 100 µg intravenously.

This was a Phase I, single-dose, open-label, randomized, 3-period, 3-treatment cross over study in which 21 healthy subjects received single doses of fentanyl 400 µg sublingual spray, Actiq® 400 µg transmucosally, and fentanyl citrate injection 100 µg intravenously following a 10-hour overnight fast. There was a 7 day washout period between treatments.

Inclusion Criteria:

• Male or non-pregnant, non-breast-feeding female between the ages of 18-55 inclusive.
• Body Mass Index (BMI) between 18-30 kg/m^2, inclusive, and body weight of at least 60 kg (132 lbs).
• Subject was healthy according to the medical history, laboratory results, and physical examination.

Exclusion Criteria:

• Had a presence or history of clinically significant cardiovascular, pulmonary, hepatic, renal, hematologic, gastrointestinal, endocrine, immunologic, dermatologic, neurologic, oncologic, or psychiatric disease or any other condition which, in the opinion of the Investigator would jeopardize the safety of the subject or the validity of the study results.
• Had a clinically significant abnormal finding on the physical exam, medical history, electrocardiogram (ECG), or clinical laboratory results at screening.
• Had a significant history of hypersensitivity to opioid analgesics, fentanyl or any related products, naltrexone, or severe hypersensitivity reactions (like angioedema) to any drugs.
• Had a significantly abnormal diet during the 4 weeks preceding the first dose of study medication.
• Had donated blood or plasma within 30 days prior to the first dose of study medication or during the course of this study.
• Had participated in another clinical trial within 30 days prior to the first dose of study medication or during the course of this study.
• Had used any over-the-counter (OTC) medication, including nutritional supplements, within 7 days prior to the first dose of study medication or during the course of this study.
• Had used any prescription medication, except hormonal contraceptive or hormonal replacement therapy, within 14 days prior to the first dose of study medication or during the course of this study.
• Had used enzyme altering drugs such as barbiturates, corticosteroids, phenothiazines, cimetidine, carbamazepine, etc, within 30 days prior to the first dose of study medication or during the course of this study.
• Had used opioid analgesics within the last 30 days.