| Nanostructured lipid carrier is a novel carrier which has been developing since the nineties of last century, and it possesses hydrophilicity, lipophilicity, targeting ability, non-immunogenicity and so on, therefore, it is a kind of extremely promising carrier. Simultaneously, nanometer lipid carrier has some advantages, such as high bioavailability, easy absorption and low toxicity, so it can be employed in medicine, cosmetics, food,genetic engineering and so on. In this experiment,medium-long-chain fatty acids were used as raw materials to prepare glycol succinate decanoate ester, which was used as the solid lipid, and tributyrin was used as liquid lipid to prepare different nanostructured lipid carriers under the condition of supercritical CO2. Furthermore, their properties were studied to provid the theoretical basis for the use of nanostructured lipid carriers.The capric acid ethylene glycol monoesters was synthesized by means of the reaction of medium-long-chain fatty acids(capric acid, lauric acid, myristic acid, palmitic acid, stearic acid) as raw materials and ethylene glycol, and then The capric acid ethylene glycol monoesters were employed to react with succinic anhydride to synthesize the ethylene glycol decanoic acid succinic acid monoester. Furthermore, its structure determined by GC, thin layer chromatography, FT-IR, NMR analysis.In this experiment, nanometer lipid carrier was prepared by using several conventiona lmethods, such as ethanol injection-extrude method, reverse phase evaporation method, supercritical compression method and supercritical CO2 injecting microemulsion method. These methods were made a comparision, and then the supercritical CO2 injecting microemulsion method was applied to prepare nanostructured lipid carrier successfully. The optimal preparation processes were studied by single factor and orthogonal experiment as follows: the nanostructured lipid carriers were prepared by using glycol fatty acid succinic acid monoester as solid lipid and tributyrin as liquid lipid through the supercritical CO2 injection hatching method. The experimental results indicated that the average particle size of nanostructured lipid carrier was157.6nm, PDI was 0.197, and Zeta potential was-34.6 ± 3.1mV when glycol fatty acid succinic acid monoester amout was 250.0mg, tributyrin amount was 80.0mg, Tween 80 amount was 230.0mg, supercritical CO2 pressure was 15 MPa, ultrasonic time was 30 min, the temperature was 50℃, and the water phase volume wasaaa 250 mL,respectively.The active substance tegafur and vitamin E were selected as model medicine to prepare nanostructured lipid carriers, and their characteristics such as particle size, distribution, potential, encapsulation efficiency, stability, appearance were studied. The appreciate conditions to prepare nanostructured lipid carriers by using tegafur and vitamin E as raw materials were as follows: when the amount of tegafur was 15.0mg, the encapsulation efficiency was 59.1%; when the average particle size was 163.6nm, Zeta potential was-30.6 ± 3.5mV. TEM electron microscopy showed that tegafur-NLC structure was the elliptic or round single room liposome. At the room temperature, its storage had little change in particle size and it released very slowly. When the VE amount was 20.0mg, the encapsulation efficiency reached 64.9%; When the average particle size was 236.4nm, Zeta potential arrived at-36.2 ± 3.3mV. TEM electron microscopy demonstrated that VE-NLC structure appeared as the round single room liposome. It was found that VE-NLC could be stored stably at room temperature for about 20 d when it was kept in the stable conditions. In the releasing experiment out of a body, it showed that VE-NLC could be released well in simulated intestinal fluid when it was released. |
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