The purpose of this study was to evaluate the astaxanthin-loaded nanostructured lipid carriers (ASX-NLC) prepared using a high-pressure homogenization transport system for local application of astaxanthin. Dynamic light scattering (DLS) and X-ray diffraction (XRD) were used to study the effect of microencapsulation on the properties of ASX-NLC. The mean size of ASX-NLC was about 108.43 ± 0.26 nm and PdI was 0.176 ± 0.002. The ASX-NLC had high encapsulation efficiency which was 95.69 ± 0.13%. Good light stability and temperature stability were shown at the ASX-NLC, indicating that the preparation process was feasible. The 2,2-diphenyl-1-pyridylohydrazinyl (DPPH) scavenging test showed that ASX-NLC could still play an antioxidant role. In vitro release studies showed that compared with an astaxanthin ethanol solution, an ASX-NLC could maintain astaxanthin release more effectively. In vitro permeation studies showed that ASX-NLC could increase astaxanthin retention in the skin. In conclusion, ASX-NLC could significantly enhance astaxanthin accumulation during dermal applications. The research results have important reference significance for local skin applications and provide a basis for the development of nanostructured lipid carriers. ASX-NLC might be suitable carriers for the local application of astaxanthin.

Summary The research assesses the properties of the phloretin‐loaded nanostructured lipid carriers (NLC) hydrogel bead. Scanning electron microscopy (SEM), dynamic light scattering (DLS) and X‐ray diffraction (XRD) were used to investigate the properties of phloretin NLC hydrogel beads. The in vitro release study indicated that the phloretin NLC hydrogel beads continued to release within 24 h. The simulated digestibility studies showed that the phloretin NLC hydrogel beads could improve digestive behaviour by controlling lipid intake. The results showed that hydrogel beads could be used as an appropriate delivery system for the encapsulation of phloretin. Hence, the NLC hydrogel beads are a potential carrier of phloretin for application in healthy food, which can control lipid intake.