Fabrication of multilayer structural microparticles for co-encapsulating coenzyme Q10 and piperine: Effect of the encapsulation location and interface thickness

The aim of this present work was to fabricating a novel multilayer structural microparticle based on zein, pectin and chitosan for co-encapsulating of nutraceuticals. Coenzyme Q10 and piperine has many physiological activities and synergistic effects, but it was challenging to co-embed them in the traditional delivery systems due to their different molecular polarities. In this study, Coenzyme Q10 was embedded into the hydrophobic zein core because it is a strongly hydrophobic molecule, whereas piperine was trapped between the polysaccharide layers (negative pectin and positive chitosan) because it is only a weakly hydrophobic molecule. The effects of low, medium, and high levels of chitosan layer thickness on the formation of the multilayer structural microparticles were studied, and the low level of chitosan layer thickness was the most suitable to form the relatively small (922 nm) and positively charged (+49.2 mV) microparticles. The entrapment efficiency of the multilayer structural microparticles was 88.7% for coenzyme Q10, and 77.2% for piperine, respectively. The microparticles protected coenzyme Q10 and piperine from chemical degradation during exposure to light, heat, and long-term storage, as well as modulated their release in simulated gastrointestinal digestion. This work would contribute to the development of more efficacious co-delivery systems for synergistic nutraceuticals with different polarities.