Merck, P0972-50MU, Polymyxin B sulfate

General description
Chemical structure: peptide
Application
Polymyxin B sulfate is a strongly cationic cyclic polypeptide antibiotic that is derived from fermentation of Bacilus polymyxa. It is a mixture of B1 and B2 sulfate. The product has been used clinically to treat infections of the urinary tract, meninges and blood stream caused by susceptible strains of Pseudomonas aeruginosa. It also has uses studying multidrug-resistant pathogens, as an immobilized agent for removal of endotoxins, and to induce pore formation in the membranes of cortex cells from excised sorghum roots.
Biochem/physiol Actions
Mode of Action: Polymyxin B Sulfate binds to the lipid A portion of bacterial lipopolysaccharides†, disrupting the cytoplasmic membrane by inducing pores large enough to permit nucleotide leakage in bacterial walls. This disrupts the permeability of the cytoplasmic membrane.

Antimicrobial spectrum: Has bactericidal action on most gram-negative bacilli††, including E. Coli and on most fungi and gram-positive bacteria.
Packaging
This product is packaged in a bottomless glass bottle, with its contents inside an inserted fused cone.
Disclaimer
As supplied, the product should be stored at 2-8°C in the dark. No change was observed in retained samples after three years′ of storage in these conditions. Stock solutions should be sterile filtered and stored at 2-8°C. They are stable at 37°C for 5 days.