Polymyxin B

Polymyxin B is a polypeptide antibiotic that targets gram-negative bacteria. It works by disrupting bacterial cell membranes, making it effective against resistant strains in clinical settings. In dermatology and skincare, its use is uncommon and primarily reserved for topical antimicrobial applications rather than general skincare benefits.The ingredient is typically encountered in prescription or clinical formulations rather than consumer skincare products, where its antimicrobial potency is valued in specific medical contexts.

Polymyxin B disrupts the outer membrane of gram-negative bacteria, compromising their structural integrity and leading to cell death. This mechanism makes it effective against organisms that have developed resistance to other antibiotics.In a skincare context, topical application delivers localised antimicrobial action, though systemic use carries significant safety considerations that limit its cosmetic application.

Polymyxin B in skincare products, where present, is typically used as directed by a healthcare professional or product instructions. If used topically in a formulation, application should follow the specific guidance provided, as this is primarily a clinical rather than routine cosmetic ingredient.

Polymyxin B is generally well-tolerated in topical formulations. However, systemic use carries documented risks including nephrotoxicity and neurotoxicity; topical cosmetic use avoids these concerns. Rare skin hyperpigmentation has been reported with systemic administration and typically resolves after discontinuation.