SPL Set ID: 7b81436e-d14a-4353-a22d-253f45e2e576

Azithromycin for injection, USP contains the active ingredient azithromycin, an azalide, a subclass of macrolide antibacterial drug, for intravenous injection. Azithromycin has the chemical name (2R,3S,4R,5R,8R,10R,11R,12S,13S,14R) -13-[(2,6-dideoxy-3- C -methyl-3- O -methyl-α- L-ribo -hexopyranosyl)oxy]-2-ethyl-3,4,10-trihydroxy-3,5,6,8,10,12,14-hepta-methyl-11-[[3,4,6-trideoxy-3-(dimethylamino)-β- D - xylo -hexopyranosyl]oxy]-1-oxa-6-azacyclopentadecan-15-one. Azithromycin is derived from erythromycin; however, it differs chemically from erythromycin in that a methyl-substituted nitrogen atom is incorporated into the lactone ring. Its molecular formula is C 38 H 72 N 2 O 12 , and its molecular weight is 749. Azithromycin has the following structural formula: Azithromycin, as the monohydrate, is a white to almost white crystalline powder with a molecular formula of C 38 H 72 N 2 O 12 •H 2 O and a molecular weight of 767.02. Azithromycin for injection, USP is a sterile preparation consisting of azithromycin monohydrate USP and the following inactive ingredients: anhydrous citric acid and sodium hydroxide. Sodium hydroxide is added to adjust the pH. Azithromycin for injection, USP is supplied as white lyophilized cake in a single-dose vial for intravenous administration. Each vial contains azithromycin monohydrate equivalent to 500 mg of azithromycin, 413.6 mg anhydrous citric acid and sodium hydroxide. Reconstitution, according to label directions, results in approximately 5 mL of azithromycin for intravenous injection with each mL containing 102.4 mg of azithromycin monohydrate USP equivalent to 100 mg of azithromycin, 82.72 mg of citric acid, and sodium hydroxide. Azithromycin Chemical Structure