An innovative phase I population pharmacokinetic approach to investigate the pharmacokinetics of an intranasal fentanyl spray in healthy subjects.

Background: Intranasal Fentanyl Spray (INFS) was developed for the treatment of breakthrough pain (BTP) in cancer patients using a new route of administration. Dose strengths of 50, 100, and 200 μg INFS (Instanyl®) are currently on the market, however, some adult cancer patients with BTP may require higher doses up to 400 μg INFS.

Objective: As pharmacokinetic (PK) samples from cancer patients with BTP are hard to obtain, PK of 400 μg INFS was investigated in healthy volunteers.