Optimization of fabrication parameters to prepare tea catechin-loaded liposomes using response surface methodology

The purpose of this study was to optimize the formulation of tea catechin-loaded nano-liposomes using response surface methodology. Response surface methodology based on central composite rotatable design has been successfully used to model and optimize biochemical and biotechnological processes. The mass ratio of phosphatidylcholine and cholesterol (1-3), catechin concentration (3-5 mg/mL), pH values of phosphate buffer solution (6-7) and the volume ratio of organic phase and aqueous phase (2-4) were selected as independent variables with encapsulation efficiency and particle size as dependent variables. For each response, a second-order polynomial model was developed using multiple linear regression analysis. Applying a desirability function method the optimum parameters were: phosphatidylcholine to cholesterol mass ratio of 2.17, catechin concentration of 5 mg/mL, pH values of phosphate buffer solution of 6.62 and organic phase to aqueous phase volume ratio of 3.05. At this optimum point, particle size and encapsulation efficiency were found to be 220 nm and 60.18%, respectively. Furthermore, leakage ratio of nano-liposomes was used to determine the influence of storage period. © Maxwell Scientific Organization, 2013.