FSE-Ag complex NS: preparation and evaluation of antibacterial activity

Silver (Ag) complexes of drugs and their nanosystems have great potential as antibacterials. Recently, an Ag complex of furosemide (Ag-FSE) has shown to be a promising antimicrobial. However, poor solubility of Ag-FSE could hamper its introduction into clinics. Therefore, the authors developed a nanosuspension of Ag-FSE (Ag-FSE_NS) for its solubility and antibacterial activity enhancement. The aim of this study was to introduce a novel nanoantibiotic with enhanced antibacterial efficacy. Ag-FSE_NS was prepared by precipitation-ultrasonication technique. Size, polydispersity index (PI) and zeta potential (ZP) of prepared Ag-FSE_NS were measured by dynamic light scattering, whereas surface morphology was determined using scanning electron microscopy (SEM). In vitro antibacterial activity was evaluated against Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa using broth microdilution method. Size, PI and ZP of optimised Ag-FSE_NS1 were 191.2 ± 19.34 nm, 0.465 ± 0.059 and -55.7 ± 8.18 mV, respectively. SEM revealed that Ag-FSE_NS1 particles were rod or needle-like with smooth surfaces. Saturation solubility of Ag-FSE in NS increased eight-fold than pure Ag-FSE. Ag-FSE_NS1 exhibited two-fold and eight-fold enhancements in activity against E. coli and S. aureus, respectively. The results obtained showed that developed Ag-FSE_NS1 holds a promise as a topical antibacterial.