Comparative pharmacokinetics of nalbuphine nasal spray and solution for injection in healthy volunteers.

Aims: Nalbuphine is a synthetic opioid with comparable analgesic activity to morphine but with a better safety profile. Nalbuphine is only available in injectable form due to low oral bioavailability. Nasal nalbuphine spray provides advantages in drug safety, avoids hepatic first-pass metabolism, is non-invasive and is convenient for patient-controlled analgesia by self-administration.