PHMB , Poly(hexamethylenebiguanide)hydrochloride 20%

PHMB is best known for its broad-spectrum antimicrobial and antifungal activity. It is the standard of care for treatment of Acanthamoeba keratitis and an ingredient in multipurpose contact lens solutions, such as Renu (Bauch & Lomb, Rochester, NY). PHMB is a cationic disinfectant that is effective against Gram-negative and Gram-positive bacteria through its electrostatic interaction with negative sites on the lipopolysaccharide component of bacterial cell membranes. 

Polyhexanide (polyhexamethylene biguanide, PHMB) is a polymer used as a disinfectant and antiseptic. In dermatological use, it is spelled polihexanide (INN) and sold under names such as Lavasept, Serasept, Prontosan and Omnicide. PHMB has been shown to be effective against Pseudomonas aeruginosa, Staphylococcus aureus (also the methicillin-resistant type, MRSA), Escherichia coli, Candida albicans (yeast), Aspergillus brasiliensis (mold), vancomycin-resistant enterococci, and Klebsiella pneumoniae (carbapenem-resistant enterobacteriaceae).

Broad spectrum antimicrobial polymer; binds and disrupts cytoplasmic membranes