Isotonic aerosol solution for the prevention and treatment of broncho-respiratory symptoms related to allergies. It contains hyaluronic acid, a phytocompound with purple basil and sage in rosmarinic acid and extracts of coleus, adhatoda, black currant and sundew. Its powdered formula forms a thin protective layer on the mucous membrane of the respiratory tract that favours its hydration and exerts an emollient and soothing action.