Prolonged Release of the Local Anesthetic Butamben for Potential Use in Pain Management

Continuous delivery of local anesthetics might be useful for management of localized and chronic pain. Controlled release injectable anesthetics have been developed but they can deliver the drug for only few days and the release is not zero-order. A drug delivery system (DDS) consisting of a perforated reservoir for drug containment and release and its potential for management of chronic pain is described. Proof of principle is detailed for long-term zero order delivery of butamben. In this study, the DDS was a polyimide tube with a 0.20 mm hole and butamben release was evaluated in vitro. It is envisioned that the DDS could be implanted in proximity to a nerve, enervating the pain source, for long-term control of chronic pain.