Metoprolol tartrate injection, USP is a selective beta1-adrenoreceptor blocking agent, available in 5 mL ampuls and 5 mL Carpuject™ sterile cartridge units, for intravenous administration. Each ampul and Carpuject™ sterile cartridge unit, contains a sterile solution of metoprolol tartrate USP, 5 mg and sodium chloride USP, 45 mg. Metoprolol tartrate USP is (±)-1-(isopropylamino)-3-[p-(2-methoxyethyl) phenoxy]-2-propanol (2:1) dextro-tartrate salt, and its structural formula is:
Metoprolol tartrate USP is a white, practically odorless, crystalline powder with a molecular weight of 684.83. Its molecular formula is (C15H25NO3)2 ∙ C4H6O6. It is very soluble in water; freely soluble in methylene chloride, in chloroform, and in alcohol; slightly soluble in acetone; and insoluble in ether.