Benzoylecgonine is the major metabolite of?cocaine. It is formed by hydrolysis of?cocaine?in the liver, catalysed by carboxylesterases. It is excreted in the urine of?cocaine?users after processing in the liver. It is the main pharmaceutical ingredient in the investigational drug Esterom, a topical solution used for the relief of muscle pain that is not FDA approved or on the market in the United States.