Preparation of Nanoliposomes Containing Rosemary Alcoholic Extract with Polyethylene Glycol Coating

Introduction: Nowadays, plant-derived compound is widely used in medical treatment as complementary therapies.Rosemary is one of these plants that have anti-angiogenic and antitumor effects.However, low solubility and low bioavailability lead to limited use of this compound.To overcome this limitation, the use of liposomes is beneficial.So, this study aimed to prepare liposomes containing rosemary alcoholic extract to obtain the best formulation with best properties to use in the antitumor study.Methods: Liposomes were prepared by Thin-Film-Hydration method in different ratios of rosemary extract, hydrogenated-soybean-phosphatidylcholine (HSPC), Cholesterol, and mPEG2000 (F1-F6).The characterization of nanoliposomes includes size, PDI (Poly dispersity index), zeta potential, encapsulation efficiency, and release rate was measured.Results: The results showed that the average particle size and zeta potential were 113.4 nm and -10.8 mV, respectively.Encapsulation efficiency showed a range of 60-90%.The average release rate of the extract was about 60%.Also, the results showed that the F1 formulation was transparent, had appropriate properties, and did not precipitate.F2 formulation was not transparent.F3-F4 formulations were precipitated, and F5-F6 formulations did not achieve the appropriate size.Conclusions: This study proved that F1 formulation in a ratio of 55:30:5 HSPC/chol/mPEG2000 is the best formulation for the preparation of nanoliposomes containing rosemary alcoholic extract to achieve the best properties for use in cancer studies.