Preparation of astaxanthin-loaded composite micelles with coaxial electrospray technology for enhanced oral bioavailability and improved antioxidation capability.

Background: Astaxanthin (AST) is approved by the US Food and Drug Administration (FDA) as a safe dietary supplement for humans. As a potent lipid-soluble keto-carotenoid, it is widely used in food, cosmetics, and the pharmaceutical industry. However, its low solubility limits its powerful biological activity and its application in these fields. This study aims to develop a delivery system to address the low solubility and bioavailability of AST and to enhance its antioxidant capacity.

Results: Astaxanthin-loaded composite micelles were successfully prepared via coaxial electrospray technology. Astaxanthin existed in the amorphous state in the electro-sprayed formulation with an approximate particle size of 186.28 nm and with a polydispersity index of 0.243. In this delivery system, Soluplus and copovidone (PVPVA 64) were the main polymeric matrix for AST, which then released the drug upon contact with aqueous media, resulting in an overall increase in drug solubility and a release rate of 94.08%. Meanwhile, lecithin, and Polyethylene glycol-grafted Chitosan (PEG-g-CS) could support the absorption of AST in the gastrointestinal tract, assisting transmembrane transport. The relative bioavailability reached about 308.33% and the reactive oxygen species (ROS) scavenging efficiency of the formulation was 44.10%, which was 1.57 times higher than that of free astaxanthin (28.10%) when both were at the same concentration level based on astaxanthin.

Conclusion: Coaxial electrospray could be applied to prepare a composite micelles system for the delivery of poorly water-soluble active ingredients in functional food, cosmetics, and medicine. © 2023 Society of Chemical Industry.