A Comparison of Composition and In Vitro Activity of Polymyxin B Products

Polymyxins are cationic cyclic polypeptides derived from various strains of Bacillus polymyxa, and have broad-spectrum activity against Gram-negative bacteria. Polymyxin B contains a mixture of polypeptides [1] and is manufactured by several companies in accordance with United States Pharmacopeia (USP) standards. Current USP polymyxin tests and assays evaluate its biological activity, and manufacturers report polymyxin B biological activity in Units (using cylinder-plate methods) and potency in Units/mg [2, 3].
Source: International Journal of Antimicrobial Agents - Category: Drugs & Pharmacology Authors: Source Type: research