Development of chitosan-gelatin loaded with copaiba oil using nanoemulsion complex coacervation

Abstract

The encapsulation of copaiba oil by complex coacervation from a nanoemulsion is developed herein. Copaiba oil is susceptible to degradation without adequate protection, including volatilization and heat and light-induced damage. Additionally, its potent aroma, insolubility in water, and restricted bioavailability significantly impede its clinical use, and to overcome these limitations, the copaiba oil was encapsulated. An oil-in-water nanoemulsion of copaiba oil was initially prepared using soy lecithin and type-B gelatin as surfactants. The mechanical dispersion at 1609 g produced stable copaiba oil submicrometric droplets, confirmed by dynamic light scattering and Zeta potential analysis. Subsequently, by adding chitosan to the nanoemulsion, a coacervate system was formed. Coacervate particles were obtained with high yields (approximately 90 %) at chitosan-to-gelatin ratios of 1:15 and 1:10. Optical and electron microscopy and Fourier-transform infrared spectroscopy supporting the incorporation of copaiba oil droplets into the coacervate particles. This coacervate process eliminates the need for chemical agents, enhances the stability of copaiba oil, and represents a promising avenue for its practical application in therapeutic formulations.