The Optimization of Encapsulation Mangosteen (Garcinia mangostana L.)-Gotu Kola (Centella asiatica L. Urban) Fraction Combination in Soybean Liposome by Response Surface Methodology

Abstract

A recent study reported that the combination of mangosteen-gotu kola fractions showed lots of bioactivities, such as strong antioxidant, anti-bacterial, and immunomodulatory activities. However, the solubility and bioavailability of the mixture combination of mangosteen-gotu kola fraction were low. Encapsulation of the mixture in a liposome was believed to increase its solubility in water, bioavailability, and medical applications due to the similar structure between a liposome and biological cell membranes. However, liposome system has a weakness, such as low encapsulation ability which are influenced by the manufacture, and the composition of the constituents, namely cholesterol, phospholipids, and encapsulated active substances. Therefore, it was necessary to optimize liposomal formulations that produce liposomes with the best encapsulation capabilities. This study was designed to optimize the encapsulation of mixture combination of mangosteen-gotu kola fraction in liposomes using thin film hydration method and response surface methodology (RSM). The RSM optimization consisted of 13 runs with two experimental factors: mass of the mixture (5.00-15.00 mg) and mass of cholesterol (11.30-22.60 mg) as independent variables. The mass of phospholipid (113.00 mg) was used as a dependent variable. The observed parameters were encapsulation efficiency (EE) and loading capacity (LC). As a result, quadratic models were used for response prediction. The maximum response was obtained using 15 mg of mixture combination, 22.60 mg of cholesterol, and 113 mg of phospholipid. It was shown that EE and LC were 82.42% and 2.18%, respectively. The liposome-loaded mixture combination obtained had a monodispersity form with a particle size and surface charge of 912.7 nm and-24.3 mV, respectively.