This is usually made by the hospital itself, and less preservatives are added. It doesn't matter whether you put it in the refrigerator or not. Just cover it in time after use, and don't expose it to the air for a long time, because there is carbon dioxide in the air. You can deal with it according to the nature of sodium bicarbonate, but the solvent is usually glycerol or something, which has nothing to do with it. The shelf life is very short ~ only half a year.