Study On The Preparation Of Lmwha-containing Liposome And Percutaneous Penetration In Vitro

Hyaluronic acid (HA) is a extracellular high molecular weight polysaccharides widely present in higher animals and lower animals. The dermis and epidermis of human skin are rich in HA. Studies have confirmed that HA have much physiological functions be exist in the human skin. For example, HA can retain water, maintain the extracellular space, protect cells, be concerned with cell proliferation and differentiation, be anti-free radicals and other. Therefore, HA repel skin aging through a variety of mechanisms function as a cosmetic additive. However, HA can not penetrate through the stratum corneum to the lower epidermis and dermis layer of the skin as a macromolecules, and can not really play a role in repel aging. HA could repel the process of skin aging fundamentally when HA infiltrate through dermal tissue. The issue is a currently problem need to be resolved developing HA anti-aging cosmetics. At present, the micro-carrier technology has been applied in the field of cosmetics as penetration enhancers. For which, we improve skin penetration performance of HA using micro-carrier technology.In this study, we improve permeability of HA in the skin through liposome enwrapping HA. The study includes: (1) Low molecular weight hyaluronic acid (LMWHA) were prepared by ultrasonic degradation. We observed the degradation of HA in the ultrasonic behavior while surveyed the relative molecular mass of HA using viscosity measurement. Then we look at the effect of different initial concentration, ultrasonic frequency, temperature and pH value of solvent on the degradation, and acquire the best preparation. (2) The LMWHA were prepared with the best preparation of low molecular weight hyaluronic acid. The LMWHA-containing liposome was prepared by reversed-phase evaporation, and was distilled by centrifugation. The entrapment efficiency of liposome was determined by measuring glucuronic acid concentration. Then we study the effect of ratio of lecithin and cholesterol, pH value of PBS, LMWHA content on the encapsulation efficiency, and design orthogonal optimization formulation process. (3) The quality of LMWHA-containing liposome was evaluated. We prepared different molecular weight HA-containing liposome and study their encapsulation efficiency, morphology, particle size and particle size distribution, leakage, chemical stability and thermal stability. (4) We designed percutaneous penetration test in vitro and study the percutaneous penetration of LMWHA-containing liposome in snake slough.The results showed that: The molecular weight of HA can be 15 to 20 million after degradation of 5 to 10h. The LMWHA-containing liposome was prepared by reversed-phase evaporation, and the entrapment efficiency of liposome was 19.2%. The average size of liposome was 441nm, and the average size of LMWHA-containing liposome was 653nm. Phospholipid, cholesterol and HA were physical integration in the liposome. In vitro permeation experiments through snake slough showed that the permeability of LMWHA-containing liposome was 3.04 times than HA.