Development and characterization of avenanthramide-loaded bilosomes: Bile salt-incorporated liposomes as a cholesterol substitute for enhanced oral delivery

Abstract

Avenanthramide (AVN), a phenolamide unique to oats, offers health benefits but is limited in application due to poor solubility, instability, and low bioavailability. This study developed bilosomes (AOE-BL) by incorporating bile salts into liposomes (AOE-LP) as a cholesterol substitute to enhance the oral delivery of AVN-enriched oat extract (AOE). AOE-BL exhibited smaller particle sizes and higher encapsulation efficiency than AOE-LP. Both formulations significantly increased AVN solubility by 2.74-fold and 2.71-fold, respectively, compared to free AOE while preventing heat-induced degradation. AOE-BL demonstrated superior stability under acidic conditions, with less pronounced changes in particle size and zeta potential than AOE-LP. After in vitro digestion, AOE-BL achieved significantly higher bioaccessibility (77.31 ± 3.31 %) than AOE-LP (67.21 ± 2.37 %) and free AOE (55.69 ± 3.43 %). Cellular uptake studies in Caco-2 enterocytes revealed that bile salts enhanced intracellular uptake compared to cholesterol. These findings highlight the potential of AOE-BL as an effective oral delivery system for AVN.