Study On The Influence Of Nanostructure Of Lipid Coated Carrier On UV Absorption Properties

Nanostructured lipid carrier(NLC)is a new submicron drug delivery system which appeared in the 1990 s.NLC is prepared from the mixed oil of solid oil and liquid oil,and the active components can be loaded in the structure.NLC can be used to coat sunscreen and apply in cosmetics.In this study,the method of phacoemulsification was used,and the sunscreen agents OMC and a plus were taken as examples.Firstly,the effects of emulsifier type,liquid oil type,solid oil type,polyol type and other components on the particle structure,UV absorption performance,particle size and PDI of sunscreen NLC were studied.It was found that the sunscreen NLC particles prepared by ionic emulsifier sodium stearoylglutamate(SG)would aggregate,while the dispersive particles of complex emulsifier system had fine and uniform structure;palmitic acid would cause NLC precipitation,and the sunscreen NLC particles prepared by waxy raw materials could obtain higher UV absorption The solubility of plus and liquid oil leads to different UV absorption.Secondly,the effect of lipid structure on the microstructure and UV absorption of NLC was studied.In the study of the effect of solid lipid on coated sunscreen NLC,it was found that the microstructure and UV absorption of sunscreen NLC were affected by lipid components and sunscreen itself.In the study of the effect of liquid lipid on coated sunscreen NLC,it is found that liquid lipid plays an important role in the solubility and dispersion of sunscreen;it is also found that the system of natural oil has synergistic effect on sunscreen NLC particles,and the UV absorption of sunscreen NLC particles increases with the increase of the number of branched chains;The results showed that the sunscreen agent appeared in the system of isododecane and isohexadecane.The structure of sunscreen agent was characterized by FT-IR,TEM.In vitro release experiments showed that the sustained-release performance of NLC was closely related to its structure.Among the prepared NLC samples,318-omc NLC had better and more stable coating performance for OMC,and the drug sustained-release performance of the system was good.The results of in vitro permeation test showed that the stronger the hydrophilicity of solid lipid,the faster the permeability of solid lipid sunscreen particles.The polarity of fatty acids was higher than that of fatty alcohols and esters.These results provide a theoretical basis for the application of NLC in sunscreen products.