Brilacidin tetrahydrochloride (PMX30063 tetrahydrochloride) is a defensin mimetic antibiotic compound, exhibiting potent anti-infective antimicrobial activity against a range of bacteria. It demonstrates MIC90 values of 1 μg mL and 8 μg mL against the Gram-positive bacteria Streptococcus pneumoniae and Streptococcus viridans, respectively. Additionally, it has a MIC90 value of 8 μg mL for the Gram-negative bacteria Haemophilus influenzae and a MIC90 value of 4 μg mL for Pseudomonas aeruginosa.