Anti-biofilm properties of a mupirocin spray formulation against Escherichia coli wound infections

Mupirocin ointment is a widely used topical drug for the treatment of bacterial skin infections. However, ointments have some limitations which motivated the development of a film forming spray of mupirocin. Mupirocin spray (2%) was formulated with Eudragit E100 as a film forming agent and tested for its antibacterial and anti-biofilm activities against Escherichia coli, a skin pathogen causing wound and surgical site infections. Treatment with mupirocin spray resulted in significant antibacterial and anti-biofilm activities (inhibition and disruption) with single spray and sub-actual dose concentrations at par with the commercial ointment concentration. The spray formulation was found to be non-toxic to fibroblast cells and greatly resisted removal from the site of application upon washing, in contrast to the ointment which was significantly removed after a single wash. This is the first study to develop and evaluate a spray formulation for mupirocin that forms a stable thin film for sustained release of the drug.