DESCRIPTION
Atracurium besylate is an intermediate-duration, nondepolarizing, skeletal muscle relaxant for intravenous administration. Atracurium besylate is designated as 2-(2-Carboxyethyl)-1,2,3,4-tetrahydro-6,7-dimethoxy-2-methyl-1-veratrylisoquinolinium benzenesulfonate, pentamethylene ester. It has a molecular weight of 1243.49, and its molecular formula is C65H82N2O18S2. The structural formula is:
Atracurium besylate is a complex molecule containing four sites at which different stereochemical configurations can occur. The symmetry of the molecule, however, results in only ten, instead of sixteen, possible different isomers. The manufacture of atracurium besylate results in these isomers being produced in unequal amounts but with a consistent ratio. Those molecules in which the methyl group attached to the quaternary nitrogen projects on the opposite side to the adjacent substituted-benzyl moiety predominate by approximately 3:1.
Atracurium Besylate Injection USP is a sterile, non-pyrogenic aqueous solution. Each mL contains 10 mg atracurium besylate. The pH is adjusted to 3.00 to 3.65 with benzenesulfonic acid. The multiple dose vial contains 0.9% benzyl alcohol added as a preservative. Atracurium besylate injection slowly loses potency with time at the rate of approximately 6% per year under refrigeration (5°C). Atracurium besylate injection should be refrigerated at 2°C to 8°C (36°F to 46°F) to preserve potency. Rate of loss in potency increases to approximately 5% per month at 25°C (77°F). Upon removal from refrigeration to room temperature storage conditions (25°C / 77°F), use atracurium besylate injection within 14 days even if rerefrigerated.