Avoid solutions containing calcium or metallic salts which form insoluble phosphates. Orange-yellow fine crystalline product. Slight odor and bitter taste. Riboflavin-5' phosphate sodium is stable in dry form when stored at room temperature. The free acid may form if stored at pH below 4.5.
Solubility is pH and temperature dependent.
Greater solubility than riboflavin. 3rd Edition. 1981. Vitamin Tolerance of Animals, 1987.