Aztreonam (CAS 78110-38-0) is the first and most widely used synthetic monocyclic beta-lactam antibiotic, belonging to the monobactam class . With a molecular weight of 435.43 and the molecular formula C₁₃H₁₇N₅O₈S₂, this antibiotic is selectively active against Gram-negative aerobic bacteria, including Pseudomonas aeruginosa, Escherichia coli, Klebsiella species, and Enterobacter species . Aztreonam functions by inhibiting mucopeptide synthesis in the bacterial cell wall through high-affinity binding to penicillin-binding protein 3 (PBP-3) . Unlike penicillin, it has poor activity against Gram-positive and anaerobic microorganisms . Available in multiple forms including injectable solutions (1g, 2g vials) for clinical use and high-purity research-grade material (95-99.82%), aztreonam serves both the human pharmaceutical and life science research markets . Understanding the…