Polymyxin B1

Polymyxin B1 is a potent antimicrobial lipopeptide first derived from Bacilus polymyxa. Polymyxin B1 is the major component in Polymyxin B (HY-A0248). Polymyxin B1 can induce lysis of bacterial cells through interaction with their membranes. Polymyxin B1 has the potential for multidrug-resistant Gram-negative bacterial infections treatment^[1][2]. In Vitro: Polymyxin B1 has antimicrobial activity that againsts Pseudomonas aeruginosa ATCC 27853, Acinetobacter baumannii ATCC BAA 747, Klebsiella pneumoniae ATCC 13883, P. aeruginosa 9019, A. baumannii 1261 and K. pneumoniae VM9 isolates with MIC values of 4 μg/mL, 2 μg/mL, 2 μg/mL, 4 μg/mL, 4 μg/mL and 2 μg/mL, respectively^[3].
Polymyxin B1 strongly inhibits protein synthesis in yeast, and in E. coli and S. aureus^[4]. In Vivo: The pharmacokinetics of Polymyxin B1 is investigated in a rat model following intravenous administration (0.8 mg/kg). The area under the concentration-time curve for Polymyxins B1 is greater than those of colistins A and B. Colistin A colistin B. The clearance value of Polymyxins B1 is 2.39 mL/min/kg, the plasma protein binding is 82.3%, the elimination half-life is 79.5 min and the AUC_0-∞ is 365 mg min/L^[5].