Innovative nanosuspension for enrofloxacin: Superior antibacterial efficacy against drug-resistant Salmonella gallinarum

Targeted drug delivery remains a significant challenge in pharmaceutical development, particularly with water-soluble drugs where controlled release at specific sites is crucial to reducing toxicity and ensuring safety. This study aimed to address this issue by developing nanosuspensions of enrofloxacin, using a lipid matrix of palmitic acid and polyvinyl alcohol as an emulsifier. These nanosuspensions were designed to enhance the bactericidal activity of enrofloxacin against Salmonella gallinarum , the causative agent of fowl typhoid in poultry. Enrofloxacin-loaded nanosuspensions were synthesized through homogenization followed by ultrasonication. Various physicochemical parameters, including zeta potential, particle size, entrapment efficiency, in vitro release profile, half-maximal inhibitory concentration (IC50), and sedimentation rate, were thoroughly characterized using scanning electron microscopy and Fourier-transform infrared spectroscopy. The results demonstrated that the enrofloxacin nanosuspensions exhibited superior antibacterial efficacy against S. gallinarum compared to the free drug, with an average particle size of 228 nm and an entrapment efficiency of 85.2 %, facilitating sustained drug release. The nanosuspension's polydispersity index (0.342) and IC50 (5.2 µg/mL) further confirmed its enhanced pharmacological potential. Statistical analyses confirmed a significant improvement in the efficacy of the nanosuspension over the free drug, suggesting its promise as a sustained-release oral formulation to combat antimicrobial resistance.