Thalidomide treats multiple myeloma and protracts life-span of patient, but its bioavailability is limited as it is poorly water soluble. Thalidomide nano-flakes are produced to improve the drug dissolution rate. Two ...Thalidomide treats multiple myeloma and protracts life-span of patient, but its bioavailability is limited as it is poorly water soluble. Thalidomide nano-flakes are produced to improve the drug dissolution rate. Two nanoflake production methods are utilized for a comparative study： a supercritical antisolvent （SAS） method and a supercritical antisolvent with enhanced mass transfer （SAS-EM）. SAS-EM utilizes ultrasonication to improve dispersion upon injection within the supercritical carbon dioxide. Comparative study of SAS and SAS-EM thalidomide confirmed that the application of ultrasonication improved the micro/nano particles produced by SAS. The effects of ultrasound power on the formation of thalidomide particles are examined. The particle size and morphology were characterized by SEM. The thalidomide nano-flakes produced by SAS-EM were smaller than the particles produced by SAS. Dissolution rates of the produced particles, evaluated by HPLC, demonstrated an increase in the thalidomide dissolution rate for the SAS-EM produced particles, The polymorphs and crystallinity of thalidomide particles （flakes） were observed by FTIR and XRD. In this research, the supercritical processing significantly modified the crystal formation of thalidomide from an original state of a β-polymorph to the amorphous state α-polymorph after suoercritical orocessing.展开更多
method of extracting astaxanthin from Phaffia rhodozyma with various solvents after acid washing was investigated. The extraction efficiency was distinctly increased after acid washing of P. rhodozyma cells. When the ...method of extracting astaxanthin from Phaffia rhodozyma with various solvents after acid washing was investigated. The extraction efficiency was distinctly increased after acid washing of P. rhodozyma cells. When the concentration of HCl was 0.4 mol.L^-1, the highest extraction efficiency of astaxanthin was achieved which was about three times higher than the control. Acetone or benzene as single polar or non-polar solvent was the most ef- fective solvent in our research. With a combination of isopropanol and n-hexane （volume ratio of 2 ： 1）, the maxi- mal extraction efficiency was achieved, approximately 60% higher than that obtained with a single solvent. The liquid-solid ratio and the extracting time were also optimized. Under the optimum extraction conditions, the extraction yield of astaxanthin exceeded 98%.展开更多
基金supported by the National 863 Programme Foundation from the Ministry of Science and Technology of the People's Republic of China(2007AA10Z350)the National Natural Science Foundation of China(20976103)
文摘Thalidomide treats multiple myeloma and protracts life-span of patient, but its bioavailability is limited as it is poorly water soluble. Thalidomide nano-flakes are produced to improve the drug dissolution rate. Two nanoflake production methods are utilized for a comparative study： a supercritical antisolvent （SAS） method and a supercritical antisolvent with enhanced mass transfer （SAS-EM）. SAS-EM utilizes ultrasonication to improve dispersion upon injection within the supercritical carbon dioxide. Comparative study of SAS and SAS-EM thalidomide confirmed that the application of ultrasonication improved the micro/nano particles produced by SAS. The effects of ultrasound power on the formation of thalidomide particles are examined. The particle size and morphology were characterized by SEM. The thalidomide nano-flakes produced by SAS-EM were smaller than the particles produced by SAS. Dissolution rates of the produced particles, evaluated by HPLC, demonstrated an increase in the thalidomide dissolution rate for the SAS-EM produced particles, The polymorphs and crystallinity of thalidomide particles （flakes） were observed by FTIR and XRD. In this research, the supercritical processing significantly modified the crystal formation of thalidomide from an original state of a β-polymorph to the amorphous state α-polymorph after suoercritical orocessing.
基金Supported by the Fundamental Research Funds for the Central Universities （FRF-AS-10-001B） and the National Natural Science Foundation of China （11071013）.
文摘method of extracting astaxanthin from Phaffia rhodozyma with various solvents after acid washing was investigated. The extraction efficiency was distinctly increased after acid washing of P. rhodozyma cells. When the concentration of HCl was 0.4 mol.L^-1, the highest extraction efficiency of astaxanthin was achieved which was about three times higher than the control. Acetone or benzene as single polar or non-polar solvent was the most ef- fective solvent in our research. With a combination of isopropanol and n-hexane （volume ratio of 2 ： 1）, the maxi- mal extraction efficiency was achieved, approximately 60% higher than that obtained with a single solvent. The liquid-solid ratio and the extracting time were also optimized. Under the optimum extraction conditions, the extraction yield of astaxanthin exceeded 98%.
