A liquid composition to provide prolonged local anesthesia after administration to a subject, whose composition consists of 12% by weight of bupivacaine as an anesthetic, 66% by weight of sucrose acetate isobutyrate as a pharmaceutically acceptable non-polymeric vehicle and 22% by weight of benzyl alcohol as a solvent for said vehicleUna composicion liquida para proporcionar anestesia local prolongada despues de la administracion a un sujeto, cuya composicion consiste en el 12 % en peso de bupivacaina como un anestesico, el 66 % en peso de isobutirato de acetato de sacarosa como un vehiculo no-polimerico farmaceuticamente aceptable y el 22 % en peso de alcohol bencilico como un disolvente para dicho vehiculo