Chitosan-Sodium Alginate Polyelectrolyte Complex Coating Pluronic® F127 Nanoparticles Loaded with Citronella Essential Oil

Pluronic® F127 nanoparticles were loaded with citronella essential oil (CEO) and then covered with chitosan-sodium alginate polyelectrolyte complex (PEC). The system was characterized according to size, zeta potential and stability over time. Dynamic light scattering (DLS) in different proportions of water/ethanol as a dispersive medium was important in confirming that PEC covered the F127 nanoparticles. Infrared spectroscopy also indicated interaction of F127 with PEC. The nanoparticle size evaluated by transmission electron microscopy (TEM) and field emission scanning electron microscopy (FESEM) corroborated the value observed in DLS (hydrodynamic radius (RH) range of 100-200 nm). Encapsulation efficiency of 80% for CEO was determined by UV-Vis spectroscopy. The release profile of the CEO was evaluated in phosphate buffer saline (PBS) containing 20% of ethanol and in simulated sweat fluid, achieving 74 and 81%, respectively. The releasing mechanism fitted the Korsmeyer-Peppas mathematical model, indicating Fickian diffusion behavior for both studied media.