Preparation, Characterization, and Antibacterial Activity of Geraniol and Citral Co‐Encapsulated Liposomes: In Vitro and In Vivo Studies

ABSTRACT The global overuse of antibiotics has accelerated multidrug resistance in Staphylococcus aureus (MRSA) and Escherichia coli ( E. coli ), which is challenging to treat clinically. Geraniol and citral have therapeutic potential but are limited by poor solubility, stability, and bioavailability. This study co‐encapsulated them in liposomes (G/C liposomes) via ethanol injection, which was optimized via single‐factor experiments and response surface methodology. The optimized G/C liposomes had good stability, high encapsulation efficiencies (geraniol, 91.74%; citral, 89.42%), 107.90 nm particle size, 0.18 PDI, and ‐4.37 mV zeta potential. In vitro, G/C liposomes displayed stronger anti‐MRSA activity than free G/C, with dose‐dependent inhibition of bacterial growth and biofilm formation. In vivo, 0.24 g/kg G/C liposomes achieved 100% survival in infected mice, with an ED 50 of 0.085 g/kg, which was lower than that of 0.12 g/kg free G/C. They also reduced IL‐6, IL‐1β, and TNF‐α levels and mitigated pathological damage to major organs. Thus, G/C liposomes enhance the solubility and stability of geraniol and citral while increasing their antibacterial activity both in vitro and in vivo.