Merck, 92283-125ML, Polymyxin B solution

General description
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.
Application
Polymyxin B is used to study 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.

Mode of Resistance: The activity of Polymyxin B sulfate is inhibited by iron(II), Co(II), Mn(II) and Magnesium ions. Polymyxin B may also be incompaitible with other microbial agents, including amphoterecin, cephalothin sodium, cephasolin sodium and heparin sodium.

Antimicrobial Spectrum: Has bactericidal action on most gram-negative bacilli, including E. Coli and on most fungi and gram-positive bacteria.
Packaging
10ml, 125ml
Preparation Note
This product is concentrated at 20 mg/mL in water, and should be stored at 2-8°C.
Other Notes
Keep container tightly closed in a dry and well-ventilated place. Containers which are opened must be carefully resealed and kept upright to prevent leakage.Handle and store under inert gas.