Preparation and characterization of eugenol-loaded oligochitosan nanoparticles through sol–gel and emulsion/sol–gel methods

The aim of this study was to prepare and characterize eugenol-loaded oligochitosan nanoparticles (Eu/Oc) via sol–gel and emulsion/sol–gel methods using tripolyphosphate (TPP) as cross-linking agent. The effect of different parameters on the particle size of nanoparticles was investigated. Purified oligochitosan (Oc) was first characterized by FT-IR and TGA methods. The increase in TPP concentration, Oc concentration, the mass ratio of Oc to TPP, and diameter of the reactor resulted in larger particles while increasing the stirring rate decreased the particle size down to a minimum level. The rate of the addition of TPP solution showed no significant effect on the particle size. The yield of nanoparticle formation was calculated as 52 ± 3%. The stability of the dispersion containing the produced nanoparticles was also investigated. The optimum particle size and the loading yield of eugenol in nanoparticles were calculated as 270 ± 45 nm and 10%, respectively. In emulsion method, emulsifier and cross-linker concentration play important roles in nanoparticles’ size and should be optimized. The results showed that particle size increases at concentrations lower and higher than the optimum value. The optimum particle size in this method was obtained as 123 ± 23 nm.