Liposome preparation
To prepare liposomes containing green tea extract, in this study, was applied of mozafari method. The superiority this method than other methods is the production of liposomes without using any solvent and detergent (Mozafari & Khosravi-Darani., 2007). In addition to, in this method do not use of homogenization or sonication methods for reduction of particle size which cause to destruction of liposome structure. The green tea extract (0.7-2 %) was first mixed with distilled water. Then phosphatidylcholine (2.5-4.5 %) and glycerol (3% v/v) were added to the green tea extract solution. The mixture was agitated on a hot plate stirrer at temperatures of (50° - 70°C) for different time intervals (30-60 min) at a mixing speed of 1,000 rpm. Finally, the mixture was placed at room temperature for one hour in order to increase the stability of the liposomes. The formulation was kept in a dark bottle at 4°C under nitrogen. Then, physicochemical properties of green tea liposomes measured such as encapsulation efficiency (EE), particle size and z- potential and determined optimal conditions to produce to green tea extract liposomes. In addition to, total polyphenol content of green tea and free radical scavenging activities of free and liposomal extract, with using DPPH method measured (Jahanfar et al., 2020).