Encapsulation of lemongrass essential oil in chitosan nanoparticles: Characterization and in vitro release study.

Abstract

Lemongrass (Cymbopogon citratus) essential oil (LEO) as a bioactive component source has a notable role in pharmaceutical, agricultural and food additives, preservative agents, medicine and nutritional supplements. The aim of the study is to produce a high quality and safe nano-formulation for human needs and an ecofriendly nano-capsule for potential applications on different natural matrices. A Gas Chromatography mass spectrophotometry analytical study of (LEO) revealed that citral was the major compound representing (64.02%) of total essential oil composition followed by myrcene, geranyl acetate and cis-verbenol. LEO was encapsulated in chitosan nanoparticles (CN) using an ionic gelation with sodium tripolyphosphate (TPP) as a cross-linking agent, and validated by attenuated total reflectance-Fourier transform infra-red ATR-FTIR spectroscopy. Most of the LEO nanocapsules particles were nearly spherical in shape with smooth surface and particle size of 205 - 210 nm and 249 nm as observed by SEM and TEM micrographs, respectively. However the Dynamic Light Scattering (DLS) studies showed that average particle size was 206.9-370.9 nm. Loading LEO onto chitosan increased the particle size and reduced the surface positive charge. This reduction in zeta potential values had a positive correlation with the initial content of LEO. By increasing the amount of LEO loaded into chitosan nanocapsule, the loading capacity (LC) increased, while the encapsulation efficiency (EE) decreased. The oil from LEO/chitosan nanoparticles demonstrated an initial rapid release profile of up to 35% after the first 10 h, followed by subsequent slower release.