Aspects of the invention include extended transdermal delivery devices for delivering buprenorphine to a subject for an extended period of time, where the transdermal delivery devices include buprenorphine, an α-hydroxy acid and a pressure sensitive adhesive. In certain instances, buprenorphine, α-hydroxy acid and the pressure sensitive adhesive are provided as a single matrix layer formulation. Also provided are methods of using the subject extended transdermal delivery devices, as well as kits containing the extended transdermal delivery device.
