Polymyxin B is a cationic surfactant antibiotic that is a mixture of polymyxin B1 and B2, which can improve the permeability of cell membranes. Almost odorless, sensitive to light, easily soluble in water, slightly soluble in ethanol. Mainly used for wounds, urinary tract, eye, ear, and tracheal infections caused by Pseudomonas aeruginosa and other pseudomonas, it can also be used for sepsis and peritonitis.