Magnesium Sulfate Injection, USP 50% is a sterile, nonpyrogenic, concentrated solution of magnesium sulfate heptahydrate in Water for Injection, USP administered by the intravenous (IV) or intramuscular (IM) routes as an electrolyte replenisher or anticonvulsant. Must be diluted before IV use.
Each mL contains: Magnesium sulfate heptahydrate 500 mg; Water for Injection q.s. Sulfuric acid and/or sodium hydroxide may have been added for pH adjustment. The pH of a 5% solution is 6.0 (5.5 to 7.0). The 50% concentration has an osmolarity of 4.06 mOsmol/mL (calc.); 2.03 mM/mL magnesium sulfate anhydrous and 4.06 mEq/mL magnesium sulfate anhydrous.
The solution contains no bacteriostat, antimicrobial agent or added buffer (except for pH adjustment) and is intended only for use as a single dose injection. When smaller doses are required the unused portion should be discarded with the entire unit.
Magnesium sulfate heptahydrate is chemically designated MgSO4 • 7H2O with a molecular weight of 246.47 and occurs as colorless crystals or white powder freely soluble in water.
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