2.1.2. Various Formulations of EGCG

In Table 1, the average particle diameters of placebo PS-, PS-EGCE-, and PS-EGCG-VEliposomes were smaller than that of placebo PC-, PC-EGCE-, and PC-EGCG-VE-liposomes, respectively. Because PC is neutral and PS is negatively charged [29], this indicates that the additive surface potential affected the particle size. Polydispersity index (PDI) of all liposomes was less than 0.22, indicating that the structure of liposomes in solution is stable. The negative charges of PS led to a repulsive force on the surface potential between PS-liposomes, avoiding aggregation and reducing the size of PS-liposomes.


**Table 1.** Characteristics of the formulation of EGCG-loaded liposomes.

PC: L-α-phosphatidylcholine; PS: phosphatidylserine; CH: cholesterol; VE: vitamin E (α-tocopherol); EGCG: (−)-epigallocatechin-3-gallate; PDI: polydispersity index.

> The encapsulation efficiency/size of PS-containing liposomes described in Table 1 was larger/smaller than that of corresponding PC-containing liposomes [30]. The encapsulation efficiency of PC-EGCG-VE-liposomes and PS-EGCG-VE-liposomes was more extensive than that of PC-EGCG-liposomes and PS-EGCG-liposomes, respectively. This is because vitamin E is fat-soluble, embedded in a phospholipid bilayer membrane, and provides an antioxidant protectant for EGCG.
