The efficacy of transdermal fentanyl for cancer pain and chronic non-cancer pain (chronic lower back pain, rheumatoid arthritis, osteoarthritis, neuropathic pain) is well established. Several formulations of fentanyl transdermal systems have been developed to improve the drug delivery and prevent misuse of the active principle. The addition of a rate controlling membrane to the matrix system represented an important advance. The design and functional features of Alghedon patch are compared with other approved generic fentanyl transdermal systems, emphasizing the distinctiveness of Alghedon patch. Alghedon patch has no liquid component in the finished product, therefore no leakage of active ingredient from the system can occur. A rate-controlling membrane provides controlled release of the active substance from the matrix reservoir, ensuring that fentanyl delivery and entry into the microcirculation is not solely controlled by the skin's permeability to this active substance. Alghedon patch contains part of the drug (approximately 15%) in the skin-contact adhesive: this innovative solution allows to overcome a typical drawback of transdermal patches, i.e. the long lag-time before the drug appears in plasma after the first administration, and provides rapid analgesia during the first hours of administration. Alghedon Fentanyl Transdermal System employs materials commonly used in other transdermal applications and having established safety profiles. For each strength level, the fentanyl content - and, thus, the resulting residual fentanyl remaining in the patch after use - is at the lowest end of the range used in commercially available fentanyl patches, minimizing the potential for abuse and misuse.