ABSTRACT
Objective: To study the preparation technology of glycyrrhetinic acid (GA)-tanshinone IIA (Tan IIA) compound liposomes (GT-Lip). Methods: The compound liposomes were made of soybean phosphatidylcholine (SPC) and cholesterol (Ch) by film dispersion ultrasonic probe method. Hydration temperature and ultrasonic power were optimized by single factor tests and the optimum formulation was selected by orthogonal design. The encapsulation efficiencies (EE) of GA and Tan IIA were determined by low-speed centrifugation. The particle size and Zeta potential of liposomes were detected by dynamic light scattering particle size meter. Transmission electron microscopy was used to observe morphous. Results: The optimal preparation conditions were as follows weight ratio of SPC-Ch 6:1, molar ratio of SPC-Tan IIA and SPC-GA was 30:1 and 24:1, hydration temperature 30 °C, and ultrasonic power 380 W for 5 min. Using the optimal method, the EE values of GA and Tan IIA in GT-Lip were (81.50 ± 0.76)% and (98.63 ± 0.90)% (n = 3), and the average particle size of liposomes was (120.5 ± 1.62) nm and the Zeta potential of liposomes was (-19.00 ± 0.98) mV (n = 3). Conclusion: The optimal preparation method of GT-Lip in this study is stable and feasible.
ABSTRACT
Objective: To establish a method for the preparation of chrysophanol freeze-dried liposomes. Methods: The liposome suspension was prepared by film-ultrasonic dispersion method. The entrapment efficiency (EE) was determined by low-speed centrifugation and the influences of pre-freezing time, drying time, and type, dosage, and adding methods of the protective agents on EE of the freeze-dried liposome were studied. Results: The pre-freezing time was 24 h, the drying time was 24 h, mannitol-sucrose (mass ratio 1:1) as protective agent was externally added to get uniform particle with good redissolution and the EE was (61.30 ± 2.2)%. Conclusion: The liposome prepared by film-ultrasonic dispersion method is protected by mannitol-sucrose to get uniform particle size with the excellent redissolution and high EE.