Preparation Of Water-Soluble Lutein Copolymer Micelle And Study On The Stability

Lutein is a kind of fat-soluble pigment which has low stability. In order to solve the problem of low water-solubility of lutein and enhance its stability. Water-soluble polymeric micelle formulation of lutein was prepared and stability of micelle was studied. The following works were done in the thesis.(1) Methoxy polyethylene glycol-polycaprolactone (MePEG-PCL)(2000:2000) amphiphilic copolymer was polymerized in solution by using Sn(Oct)2as catalyst. Polyethylene glycols stearic acid diester (2000DS) amphiphilic copolymer was polymerized through high temperature melting by using PTSA as catalyst. Infrared spectrum,1H NMR spectrum and CMC of these two copolymers were determined.(2) Amphiphilic block copolymer MePEG-PCL was applied as carrier to encapsulate lutein to form polymeric micelle by self-emulsion solvent evaporation method. The optimal experimental conditions to prepare polymeric micelle formulation of lutein were determined according to the design of single factors. The result showed that the optimum conditions of preparation were as follows:mixing time was5h, solvent evaporation temperature was25℃, the ratio of lutein and carrier was1:10, the ratio of solvent to water was1:2.(3) MePEG-PCL and2000DS were applied as carrier to encapsulate lutein respectively. The relative indexes of these two copolymers were determined included drug loading rate, particle size, microstructure, solubility. The results showed that the drug loading rate of lutein encapsulated by MePEG-PCL was higher and the particle size was smaller. The solubility of lutein encapsulated by2000DS was higher.(4) The effects of different factors such as pH, light, oxygen, temperature, metal ions on the lutein micelle stability were studied, and compared with the lutein not encapsulated. The results showed that stability of lutein encapsulated by MePEG-PCL was better. The light stability and thermal stability of the encapsulated lutein was better than lutein not encapsulated and the influence of pH and the degradation of oxygen to lutein were decreased.