Vitamin K3 Menadione Sodium Bisulfite (MSB)

Menadione sodium bisulfite (CAS 130-37-0), also known as Vitamin K3 sodium bisulfite and commonly abbreviated as MSB, is the water-soluble bisulfite addition compound of menadione used as a source of provitamin K3 activity. Its water solubility makes it the preferred form of menadione for aqueous formulations across pharmaceutical, nutritional, and animal feed applications. In animal feed and premix manufacturing, MSB is incorporated into poultry, swine, and aquaculture feeds.

It supports blood coagulation function, where it is dosed at established inclusion rates regulated by feed authorities. Pharmaceutical manufacturers use it to produce injectable and oral dosage forms requiring a stable, water-dispersible vitamin K3 source. In veterinary nutritional supplements, MSB is blended into concentrated premixes and water-soluble powder formulations for livestock administration. It also appears in aquaculture feed concentrates where fat-soluble vitamin forms are impractical to process.

Menadione sodium bisulfite is supplied as a white to off-white crystalline powder. Standard grades include feed-grade material conforming to specifications set by pharmacopoeial references such as USP and BP. It is also available as technical-grade material for industrial premix use. Bulk supply is typically available in 25 kg bags, with activity content standardized and declared on a percentage basis for quality assurance.