Encapsulation of Green Tea Extract (GTE) in Nanoliposome and Assessment of Its Characterization and In Vitro Release Study of GTE

This study aimed to encapsulate GTE in liposomes using a thin-film ultrasonic dispersion method to enhance its stability and bioavailability. The optimal formulation used a tea polyphenol-to-lecithin ratio of 0.125:1, lecithin-to-cholesterol ratio of 4:1, and PBS at pH 6.62, yielding liposomes with an encapsulation efficiency (EE) of 60.09%, corresponding to the optimized formulation (Sample T25: phosphatidylcholine:cholesterol ratio of 2:1, 0.6% Tween 80, and 1000 ppm GTE), selected for its balance of size, stability, and performance, a particle size of 99.2 ± 0.34 nm, and a zeta potential of approximately -30 mV. Antioxidant activity, measured by the DPPH assay, showed that encapsulation significantly improved the free radical scavenging ability of green tea polyphenols. Additionally, release kinetics in simulated gastric (SGF) and intestinal fluids (SIF) followed a biphasic profile, with an initial burst release followed by sustained release, fitting best with the Korsmeyer-Peppas model. Stability studies demonstrated that the liposomal formulation maintained consistent particle size and EE over 90 days, confirming its ability to preserve GTE's bioactivity under simulated physiological conditions. These findings emphasize the potential of liposome-encapsulated green tea polyphenols as an effective delivery system, offering enhanced stability and bioavailability for food and therapeutic applications. The study provides insights into optimizing liposomal formulations for the delivery of bioactive compounds, supporting their use in functional foods and nutraceuticals.