Lippia sidoides Essential Oil Encapsulation by Angico Gum/Chitosan Nanoparticles

Chitosan (CH) and angico gum (AG) nanoparticles were loaded with essential oil, Lippia sidoides (Ls), being characterized according to their composition, size distribution, Ls: polymer ratio, thermal stability and in vitro and in vivo controlled release. Nanoparticles prepared using Ls:AG ratios of 1:2 to 1:20 had loading values of 3.3 to 7.7%, with encapsulation efficiencies in the range of 16.0 to 77.8%. Particle sizes were in the range of 10-60 nm and size distributions were independent of Ls content, for different Ls:AG ratios. Infrared spectroscopy revealed the presence of thymol in the nanoparticles. TGA and DSC revealed that the degradation temperature of AG-CH nanoparticles decreased with an increase in Ls content. Controlled-release data showed a slower release profile for samples with Ls: AG = 1:10 than for the other samples. Bioassays showed that sample Ls: AG = 1:10 has a greater larvicidal effect, with 85 +/- 3% mortality.