US Patent 6921541 Formulations and methods for providing prolonged local anesthesia

A formulation and methods for inducing sustained regional local anesthesia in a patient comprising a substrate comprising a local anesthetic and an effective amount of a biocompatible, biodegradable, controlled release material prolonging the release of the local anesthetic from the substrate to obtain a reversible local anesthesia when implanted or injected in a patient, and a pharmaceutically acceptable, i.e., non-toxic, non-glucocorticoid augmenting agent effective to prolong the duration of the local anesthesia for a time period longer than that obtainable from the substrate without the augmenting agent.