CARLSBAD, Calif.--(BUSINESS WIRE)--Encore Therapeutics Inc. (ETI) today announced that it has developed a proprietary extended release depot formulation of the local anesthetic ropivacaine (F-93). Extensive pre-clinical studies demonstrate that F-93 achieved a 5-10 fold extension of local anesthetic efficacy compared to the currently marketed product, Naropin™. Ropivacaine is preferable over other local anesthetics such as bupivacaine because of its greater selectivity for sensory neurons and because it is less cardiotoxic. These properties make it more useful clinically than other extended release local anesthetic products that are currently in development.