Sustainable liposomal delivery of Centella asiatica polyphenols: β-sitosterol stabilization, LC-MS/MS profiling, and simulated release study

Abstract

This study investigates the influence of β-sitosterol (βS) on the structural characteristics, physicochemical stability, and in vitro release behavior of liposomes encapsulating Centella asiatica leaf extract (CALE). Additionally, the retention kinetics of bioactive compounds were analyzed using a first-order equation alongside assessments of thermal stability and lipid oxidation. The polyphenolic composition of CALE was characterized through LC-MS/MS in both positive and negative ionization modes, revealing the presence of several key compounds with distinct retention times. Findings indicated that the highest encapsulation efficiency (74.789 ± 0.811%) was achieved when the soy lecithin (SL) to β-sitosterol (βS) ratio was 7 : 3 (LP-βS (C3)). The particle size of all formulations remained under 700 nm, with a retention rate exceeding 50% after 28 days of storage. FTIR analysis confirmed the absence of interactions between polyphenols and the encapsulating material, validating the successful encapsulation of bioactive compounds. Furthermore, simulated release studies demonstrated that encapsulation enhanced the bioavailability of CALE bioactive compounds in liposomes. These findings suggest that βS is a viable and promising approach for developing cholesterol-free, bioactive-enriched liposomal formulations suitable for functional food applications.