Nasal delivery of fentanyl.

Fentanyl, a potent opioid analgesic, is rapidly and efficiently absorbed from the nasal cavity, giving significant potential for nasally administered fentanyl to be used in pain management. Many reported clinical studies have used nasally administered IV solution, often as drops, which requires high volumes of solution to deliver an effective dose, resulting in insignificant runoff and drip which, in turn, compromises absorption and efficacy. More recently, products have been developed and commercialised with features intended to overcome these drawbacks, notably delivering the dose as a spray in a lower volume of solution and, for one of the products, incorporating an in situ gelling agent with the aim of both reducing runoff/drip and modifying the fentanyl absorption profile. The commercial fentanyl nasal spray products (PecFent/Lazanda and Instanyl) are currently licensed solely for the treatment of breakthrough pain in cancer patients; they have a number of advantages over oral transmucosal (buccal/sublingual) products used in the same indication, including faster onset of action and easier administration, especially in patients suffering from oral cavity disorders associated with cancer treatment. Given the nature of fentanyl, regulatory agencies will expect that appropriate safety features are incorporated into the primary and secondary packaging in products intended for use by patients in the home and may also impose risk management protocols to control the distribution and prescription of controlled substances. These demands notwithstanding, intranasal fentanyl offers much future promise, including for additional indications and paediatric use.