The Study On Preparation Of Actives Complex Using Supercritical CO₂ Impregnation Technology

Actives are always used as supplements to enhance the physiological functions, however, they are hydrophobic and instable and thus low bioavailability. Hence, it is necessary to prepare actives into the complex to improve the bioavailability. Comparing with the products that prepared by traditional methods, the complex manufactured by supercritical carbon dioxide impregnation technology is organic agents free. In addition, the efficiency of the preparation increases, due to the property of the supercritical carbon dioxide. In this study,α-tocopherol, lutein, linolenic acid ethyl ester,β-cyclodextrin and mesoporous silica were used as models and carries respectively to prepare actives complex by supercritical carbon dioxide impregnation technology.α-tocopherol/β-cyclodextrin complex was prepared by supercritical carbon dioxide impregnation technology. The effect of process parameters, such as pressure, temperature and time, on loading capacity and dispersiveness in water were studied. Ultraviolet spectrophotometer was employed to determine the load ofα-tocopherol. In addition, the products were characterized by FTIR, DSC and TGA. The results show that the load capacity increases with the rise of temperature and pressure at first, then decreases with the increase of temperature and pressure, which reaches the maximum of 38.7% at the temperature of 35℃, the pressure of 18MPa and impregnation time of 1h and remains the same with the increase of time. Also, the complex disperses homogeneously in water.α-tocopherol/mesoporous silica complex was prepared by supercritical carbon dioxide impregnation technology. At first, different types of mesoporous silica were successfully prepared. Then UV-VIS spectrophotometer, photos and SEM were employed to study the structure and dispersion ofα-tocopherol in mesoporous silica. The effect of different silica and operation parameters such as impregnation pressure and temperature were also studied. The results shows the load capacity increases with the rise of temperature and pressure at first, then decreases with the increase of temperature and pressure, which reaches the maximum of 79.88% at the temperature of 35℃, the pressure of 18MPa and with the silica of SBA-15③.Lutein and linolenic acid ethyl ester complex were prepared by supercritical carbon dioxide impregnation technology. The effect of actives on the load capacity and stability of lutein complex were studied. The result shows that the stability increases in the complex.Finally, the rules of preparing actives complex has been mastered through the research. Also, the effect of operation parameters, carriers and actives on the load capacity has been grasped and a new technology of preparing the complex has been established.