Improved in vitro digestion stability of (-)-epigallocatechin gallate through nanoliposome encapsulation.

(-)-Epigallocatechin gallate (EGCG) is unstable and degraded in near-neutral or alkaline fluids. To overcome its limitation, EGCG nanoliposome (EN) was prepared by an ethanol injection method combined with dynamic high-pressure microfluidization. EN possessed good physicochemical characterizations (high entrapment efficiency=92.1%, small average particle size=71.7nm, low polydispersity index=0.286 and zeta potential=-10.81mv). EN exhibited a relative good sustained release property. Stability of EGCG in simulated intestinal fluid (SIF) was significantly improved by nanoliposome encapsulation. After 1.5h incubating in SIF without or with pancreatin, the residual EGCG of EN was 31.2% and 47.7% respectively, but the residual EGCG in EGCG solution was only 3.4% and 3.5% respectively. The degenerations of in vitro antioxidant activities of EGCG were effectively slowed by nanoliposome encapsulation. This study expects to provide theories and practice guides for further applications of EN.