Levofloxacin loaded clove essential oil nanoscale emulsion as an efficient system against Pseudomonas aeruginosa biofilm

Biofilm formation by bacteria has become one of the major reasons for escalation of antimicrobial resistance. The present research focused on the development, optimization and evaluation of antibiofilm potential of clove oil nanoscale emulsion (o/w) loaded with levofloxacin (LFX-NE) against Pseudomonas aeruginosa biofilm. The optimized NE was selected through the construction of pseudo-ternary phase diagrams and was found to be stable. The particle size and drug content of LFX-NE was found to be 18.84 ± 0.5 nm and 99.2 ± 0.5%, respectively. It demonstrated high antibacterial activity with 16-fold and 8-fold reduction in MIC of LFX against P. aeruginosa and Escherichia coli and Klebsiella pneumoniae, respectively. LFX-NE was able to eradicate pre-formed biofilm of P. aeruginosa as evidenced by field emission scanning electron microscopy and confocal laser scanning microscopy. Antiquorum sensing study revealed inhibition of quorum sensing activity. LFX-NE was found to be non-irritant and cytocompatible as confirmed by HET-CAM test and safety study in normal human epidermal keratinocytes (NHEK) cell line. This study demonstrates the potential of LFX-NE in possible treatment of non-healing wounds inflicted with bacterial biofilm. [Display omitted] •Levofloxacin was loaded into clove oil nanoscale emulsion (LFX-NE).•LFX-NE showed nanometric size and excellent thermodynamic stability.•LFX-NE eradicated mature Pseudomonas aeruginosa biofilm after 6 h treatment.•LFX-NE was found to be cytocompatible with normal human epithelial keratinocytes.•LFX-NE has great potential for treatment of biofilm harbouring non-healing wounds.