Riboflavin-5'-Phosphate Sodium

Riboflavin-5'-phosphate sodium, also called riboflavin sodium phosphate or FMN sodium, is the monosodium salt of the 5'-monophosphate ester of riboflavin. It carries CAS 130-40-5, formula C17H20N4NaO9P with a molecular weight of 478.33 on the anhydrous basis, and is normally traded as the dihydrate C17H20N4NaO9P·2H2O at 514.36 (CAS 6184-17-4). The material is a yellow to orange-yellow crystalline hygroscopic powder. Both USP and Ph. Eur. monograph 0786 set the assay as 73.0-79.0% of riboflavin calculated on the dried basis, with related-substance limits of not more than 6.0% free riboflavin and not more than 6.0% riboflavin diphosphate. The practical reason formulators select this ester over riboflavin itself is solubility: one gram dissolves in about 30 mL of water, against roughly three to twenty litres for riboflavin, so it can be carried in clear liquids, syrups, effervescent systems and parenteral solutions where riboflavin would remain a suspended solid. Because only about three quarters of the mass is riboflavin, dosing has to be recalculated against the declared assay rather than substituted weight for weight. Riboflavin itself is converted in the body to the coenzymes FMN and FAD, which carry hydrogen in the oxidation-reduction reactions of normal energy metabolism; riboflavin-5'-phosphate sodium is also authorised as a food colour under E 101(ii) / INS 101(ii). Thovek supplies pharmacopoeial and food-grade material with a 1% aqueous solution pH of 5.0-6.5, specific rotation of +37.0 to +42.0 degrees (USP) or +38.0 to +43.0 degrees (Ph. Eur.), loss on drying not more than 7.5%, residue on ignition not more than 25.0%, and inorganic phosphate not more than 1.0% as PO4 under USP or 1.5% under Ph. Eur. The powder is hygroscopic and light-sensitive, so drums are sealed with desiccant and handled under subdued light; opened containers should be resealed promptly. Each lot ships with CoA, MSDS, allergen, GMO, BSE/TSE and halal/kosher statements, certificate of origin, and any certificate of free sale the destination market requires.