Preparation And Properties Of Folic Acid Nano-liposomes

As an important drug delivery system, Liposomes could not only efficiently protect the targeting drugs, but also enhance its utilization and stability, which has a promising development future. With all properties of liposomes, Nano-liposome could significantly better the metabolic dynamic actions of drugs, which allows it has a wide usage in clinical application of neoplasm prevention and treatment.As a water-soluble drug, folic acid involves in many human metabolic activities, which has great significance to the maintenance of human health. However, folic acid is very unstable, vulnerable to external conditions and has low bioavailability. This paper intends to prepare nano-folic acid lipsomes, better its preparation technology and test the properties of the prepared lipsomes.Taking lecithin and cholesterol as membrane material, folic acid as targeting drugs, the folic acid liposomes was prepared by methods of thin film evaporation method, reverse evaporating method, double emulsification method, ethanol injection method and lyophilization method. According to their different encapsulation efficiency and particle size, select and optimize the methods through single factor experiments and orthogonal test. The optimum methods were as follows:the mass ratio of lecithin and ethanol was 5:1, the folic acid concentration was 1.4 mg/ml, the preparation temperature was 60℃, the aqueous pH was 8.0. Under these conditions, the folic acid liposomes had 43.34% folic acid encapsulation efficiency with a mean particle size of 298.3nm, which match the need of basic pharmaceutics requirements.Based on the front formula, the nano-folic acid liposome was prepared by thin film evaporation method coupled with dynamic high pressure technology. According to encapsulation efficiency and particle size of the nano-folic acid liposome, select and optimize the proceedings of dynamic high pressure technology through single factor experiments. The optimum conditions were as follows:processing temperature was 55℃, processing pressure was 120MPa, processing times was twice.Under these conditions, the nano-folic acid liposome had 53.23% folic acid encapsulation efficiency with a mean particle size of 90.8nm, which has a thin size distribution.The exploration of nano-folic acid liposome properties shows that the nano-folic acid prepared by film evaporating method coupled with dynamic high pressure technology had advanced thermal stability, physical stability and storage stability. With thin particle size distribution and high encapsulation efficiency, the prepared liposomes were white uniform solution, which meet the requirements of preparations.