SPL Set ID: bf7a0845-de4f-46be-841a-0faf47f8b530

Sulfamethoxazole and Trimethoprim Injection USP, a clear, colorless to slight yellow, sterile solution for intravenous infusion only, is a combination of sulfamethoxazole USP, a sulfonamide antimicrobial, and trimethoprim USP, a dihydrofolate reductase inhibitor antibacterial. Each mL contains: sulfamethoxazole, USP 80 mg; trimethoprim, USP 16 mg; benzyl alcohol 10 mg (1.0% v/v and 1.0% w/v) as a preservative; diethanolamine 3 mg (0.3% v/v and 0.3% w/v); ethyl alcohol 100 mg (12.3% v/v and 10.0% w/v); propylene glycol 400 mg (38.6% v/v and 40.0% w/v); sodium metabisulfite 1 mg as an antioxidant; water for injection q.s.; air replaced with nitrogen; pH adjusted with sodium hydroxide and/or hydrochloric acid if necessary. pH: 9.5 to 10.5. Trimethoprim, USP is 2,4-diamino-5-(3,4,5-trimethoxybenzyl) pyrimidine. It is a white to light yellow, odorless, bitter compound with a molecular weight of 290.32 and the following structural formula: C 14 H 18 N 4 O 3 M.W. 290.32 Sulfamethoxazole, USP is N 1 -(5-methyl-3-isoxazolyl) sulfanilamide. It is an almost white, odorless, tasteless compound with a molecular weight of 253.28 and the following structural formula: C 10 H 11 N 3 O 3 S M.W. 253.28 Trim sulfa