Riboflavin-5-phosphate sodium (sodium FMN) consist mainly monosodium salt of Riboflavin 5-phophate (FMN), the 5-monophosphate ester of riboflavin. Riboflavin-5-phosphate sodium is produced by direct reaction of riboflavin with a phosphorylating agent such as phosphorous oxychloride in an organic solvent.
Riboflavin 5-phophate (FMN) is essential as a coenzyme in various enzymic reactions in the body and is therefore used in the form of its salts, especially in the form of sodium FMN, as additive to drugs and human and animal food. Sodium FMN is also used as starting material for flavin adenine dinucleotide which is employed for treating vitamin B2 deficiency. It is used as a yellow food color additive (E106). Riboflavin 5-phosphate sodium is fairly stable in air but is hygroscopic and sensitive to heat and light. The product may be stored for 33 months from the date of manufacture in the unopened original container and at a temperature below 15 °C.