Sulfocillin sodium is a semisynthetic, broad-spectrum penicillin antibiotic. It is the sodium salt of sulfocillin, a β-lactam antibiotic belonging to the ureidopenicillin subclass. Its chemical structure features a penicillin core with a sulfobenzyl side chain, which contributes to its antibacterial profile. This compound is primarily used as an active pharmaceutical ingredient (API) for the treatment of various bacterial infections. It exhibits activity against a range of Gram-positive and Gram-negative bacteria, including *Pseudomonas aeruginosa*. Its mechanism of action involves inhibiting bacterial cell wall synthesis by binding to penicillin-binding proteins (PBPs). It is administered via injection (intravenous or intramuscular) and is particularly indicated for serious infections where broad-spectrum coverage is required. Sulfocillin sodium is sensitive to degradation by β-lactamases. Its clinical use has been largely superseded by newer generations of penicillins and cephalosporins with improved stability and spectra, but it remains a part of the historical and pharmacological landscape of β-lactam antibiotics.