Preparation, Characterization, and Antibacterial Evaluation of Nanoemulsions and Chitosan Nanoparticles Containing Lemongrass Essential Oil and Citral against Staphylococcus aureus and Pseudomonas aeruginosa

Bacterial infections, particularly those caused by Staphylococcus aureus and Pseudomonas aeruginosa, represent significant global health challenges. Lemongrass essential oil (EO) and its active compound citral exhibit antibacterial properties, but their low solubility and efficacy limit their therapeutic potential. This study explores the potential of nanoemulsions and chitosan nanoparticles to enhance the efficacy of lemongrass EO and citral. Nanoemulsions and chitosan nanoparticles were prepared using spontaneous emulsification and ionic gelation methods, respectively. The formulations were characterized for particle size, SPAN, and zeta potential using dynamic light scattering (DLS). Antibacterial activity was evaluated using a microdilution assay, and IC50 values were calculated. The prepared nanoemulsions and chitosan nanoparticles demonstrated particle sizes below 200 nm and stable zeta potential values exceeding -30 mV. Successful loading of EO and citral was confirmed by Attenuated Total Reflectance Fourier-Transform Infrared (ATR-FTIR) analysis. Non-formulated lemongrass EO and citral exhibited limited antibacterial activity; however, their encapsulated forms showed enhanced efficacy. Nanoemulsion containing lemongrass EO demonstrated an IC50 of 62 mu g/mL against S. aureus, while chitosan nanoparticles containing lemongrass EO had an IC50 of 344 mu g/mL against P. aeruginosa. These results highlight the potential of nanoencapsulation to improve the stability and antibacterial activity of natural compounds like lemongrass EO and citral. This approach offers a promising strategy for combating antibiotic-resistant bacteria, warranting further exploration for therapeutic applications.