– Cephalexin (Cefalexin) hydrochloride monohydrate is a potent, orally active, semisynthetic cephalosporin antibiotic with a broad antibacterial spectrum against gram-positive and gram-negative bacteria. It operates by targeting penicillin-binding proteins (PBPs) to inhibit bacterial cell wall synthesis and is utilized in research on various bacterial infections, including pneumonia, strep throat, and bacterial endocarditis [1] [2].