Improved intestinal absorption and oral bioavailability of astaxanthin using poly (ethylene glycol)‐graft‐chitosan nanoparticles: preparation, in vitro evaluation, and pharmacokinetics in rats

Astaxanthin (ASTA) is a kind of food-derived active ingredient (FDAI) with antioxidant and antidiabetic functions. It is nontoxic but its poor solubility and low bioavailability hinder its application in the food industry. In this study, a novel carrier, polyethylene glycol-grafted chitosan (PEG-g-CS) was applied to enhance the bioavailability of astaxanthin. It encapsulated astaxanthin completely by solvent evaporation to manufacture astaxanthin using poly (ethylene glycol)-graft-chitosan nanoparticles (ASTA-PEG-g-CS) nanoparticles to improve absorption.The ASTA-PEG-g-CS nanoparticles were spherical, with a particle size below 200 nm and a ζ potential of about -26 mV. Polyethylene glycol-grafted chitosan can encapsulate astaxanthin well, and the encapsulated astaxanthin was released rapidly - in 15 min in an in vitro release study. In a rat single-pass intestinal perfusion study, a low concentration of ASTA-PEG-g-CS nanoparticle (0.2 μg mL-1 ) was better absorbed in the intestine. In particular, the jejunum could absorb most astaxanthin without a change in the concentration. An in vivo release study also demonstrated that ASTA-PEG-g-CS nanoparticles enhanced oral bioavailability significantly.This novel carrier, PEG-g-CS, provided a simple way to encapsulate food, which improved the bioavailability of hydrophobic ingredients. © 2021 Society of Chemical Industry.