The invention relates to a medicinal product (10), in particular sterile medicinal product, comprising a flexible mono-chamber container (14) and an aqueous liquid (12) containing bicarbonate and having a physiological pH value, wherein the container (14) comprises a first side wall (15a) and a second side wall (15b), wherein the first side wall (15a) and the second side wall (15b) comprises a barrier material which is capable of preventing or retarding escape of carbon dioxide from the container (14) and/or intake of carbon dioxide into the container (14) such that the pH value of the aqueous liquid (12) is maintained or substantially maintained during a shelf life at room temperature of the medicinal product (10) for at least 12 months.
