Magnesium Oxide

Magnesium oxide (CAS 1309-48-4, MgO, molecular weight 40.30) is the simplest and most concentrated magnesium source used in nutritional and pharmaceutical manufacture, carrying approximately 60.3% elemental magnesium by mass. It is supplied in two commercial families that share the same chemistry but differ in calcination history and particle morphology: light magnesium oxide, a very bulky low-density powder, and heavy magnesium oxide, a denser free-flowing powder with a bulk density typically above 0.25 g/mL. Assay is 96.0-100.5% MgO calculated on the ignited basis in line with USP/NF and FCC. The material is practically insoluble in water, insoluble in ethanol and soluble in dilute acids, which governs how it is used. The high elemental load means a small weight contribution per unit dose, so it is widely chosen where tablet or capsule space is constrained. Heavy grade is generally preferred for direct compression, capsule filling and dry premixes; light grade is chosen for suspensions and wherever bulk and absorbency are wanted. Magnesium is an essential mineral with established roles in normal muscle function, normal functioning of the nervous system, normal protein synthesis and the maintenance of normal bones and teeth. Every lot is despatched with a certificate of analysis covering assay on the ignited basis, loss on ignition, free alkali and soluble salts, acid-insoluble substances, calcium, iron, arsenic, lead and heavy metals. ICP-MS elemental profiling, residual solvent screening and microbiological testing are available on request, together with allergen, GMO, BSE/TSE and non-irradiation declarations. Export documentation includes CoA, MSDS, certificate of origin and, where required, a certificate of analysis countersigned against the nominated pharmacopoeia.