Physicochemical properties, antioxidant activities and in vitro sustained release behaviour of co‐encapsulated liposomes as vehicle for vitamin E and β‐carotene

BACKGROUND In this study the potential of liposomes as a vitamin E (VE) and β‐carotene (βC) delivery system was examined. The co‐encapsulated liposomes of βC and VE (L‐VE‐βC) were prepared and characterized. Their antioxidant properties were evaluated by free radical scavenging activities of 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH), 2,2′‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulfonic acid (ABTS), hydroxyl radical and lipid peroxidation assay. The in vitro sustained release behaviour was then investigated and discussed. RESULTS VE and βC were co‐encapsulated in liposomes with high encapsulation efficiency, up to 92.49% and 86.16% for βC and VE, respectively. The antioxidant activities of L‐VE‐βC samples were significantly higher than that of single loaded liposome. Among different ratios of VE/βC, L‐VE‐βC at 5:3 exhibited the highest radical scavenging rates, with 66.80%, 56.58% and 34.39% for DPPH, ABTS and OH radical, respectively. L‐VE‐βC samples also had a good ability to inhibit lipid peroxidation, especially the sample with ratios of VE/βC at 5:3 and 3:1. In simulated gastrointestinal release, L‐VE‐βC exhibited an excellent sustained release behaviour in SGF with the accumulated rate at about 20%, while the release rate in SIF increased to over 80%, where they should be absorbed. The release kinetics analysis indicated that βC was released in the Higuchi model in stomach, and the Korsmeyr–Peppas model in intestine. CONCLUSION Compared to single loaded liposomes, the combined‐loaded liposomes exhibited higher antioxidant activity and bioavailability, suggesting the potential applications in functional foods. © 2022 Society of Chemical Industry.