Design and functionality of a smart fentanyl iontophoretic transdermal system for the treatment of moderate-to-severe postoperative pain.

Fentanyl iontophoretic transdermal system (ITS) is a patient-controlled analgesia system used for the management of acute postoperative pain. The first-generation fentanyl ITS was an integrated one-piece system; however, corrosion that could limit reliability was detected in a small number of systems. A second-generation fentanyl ITS was designed to separate the hydrogels in the Drug Unit from the electronic circuit of the Controller during manufacture and storage, removing the primary cause of corrosion and thereby improving reliability. No evidence of corrosion has been observed in over 10,000 systems tested in real-time aging studies for the second generation fentanyl ITS. The second generation fentanyl ITS design features combine to ensure safe operation of the system with high reliability.