Can mannitol, a natural, plant-derived sugar alcohol commonly used in chewing gum, cosmetics and baking, be the solution to relieving chronic and acute pain? Two Vancouver-based female medical professionals with a special interest in pain management say yes.     After almost a decade of research and testing, QR (Quick Relief) Cream, an OTC pain-relief cream powered by mannitol, has debuted in the US market.    QR Cream’s mannitol can be applied directly to painful areas to interrupt the sign...