Solid dispersion(SD)systems have been extensively used to increase the dissolution and bioavailability of poorly water-soluble drugs.To circumvent the limitations of polyvinylpyrrolidone(PVP)dispersions,HPMC E5 was ap...Solid dispersion(SD)systems have been extensively used to increase the dissolution and bioavailability of poorly water-soluble drugs.To circumvent the limitations of polyvinylpyrrolidone(PVP)dispersions,HPMC E5 was applied in the formulation process and scaling-up techniques,simultaneously.In this study,SD of nimodipine(NMP)and corresponding tablets were prepared through solvent method and fluid bed granulating one step technique,respectively.Discriminatory dissolution media were used to obtain reliable dissolution results.Meanwhile,the stability study of SDs was investigated with storage under high temperature and humidity conditions.Moreover,the solubility of SDs was measured to explore the effect of carriers.The preparations were characterized by DSC,PXRD,and FTIR.Dramatical improvements in the dissolution rate of NMP were achieved by the ingenious combination of the two polymers.Binary NMP/PVP/HPMC-SDs released steadily,while the dissolution of single NMP/PVP-SDs decreased rapidly in water.The fluid-bed tablets(FB-T)possessed a similar dissolution behavior to the commercial Nimotop TM tablets.The characterization patterns implied that NMP existed in an amorphous state in our SDs.Furthermore,the results of stability tests suggested a better stability of the binary SDs.A special cooperative effect of PVP and HPMC was discovered on dissolution characteristics of NMP SDs and tablets,which could be extended to other drugs henceforth.Finally,the bioavailability of FB-T was evaluated in beagle dogs with Nimotop TM as the reference,and the results showed a higher AUC 0–12h value for FB-T.展开更多
Enhancing the tunneling magneto-Seebeck(TMS) ratio and uncovering its underlying mechanism are greatly demanded in spin caloritronics.The magnitude and sign of the TMS effect depend on the type of atom and the stackin...Enhancing the tunneling magneto-Seebeck(TMS) ratio and uncovering its underlying mechanism are greatly demanded in spin caloritronics.The magnitude and sign of the TMS effect depend on the type of atom and the stacking order of atoms at the interfaces.Herein,we demonstrate that TMS ratios can be effectively manipulated by altering heterogonous or homogeneous interface through decoration on the CoFeSi(001) surface inserted on the MgO insulating layers.The maximum TMS ratio of pure Co_(2)/O termination is 4565% at 800 K.Notably,the TMS ratio of the FeSi/O termination has two peak values,of which the maximum could reach up to-3290% at 650 K.By comparing two different atom arrangements at the interface,we reveal that the sign and symbol of the TMS ratio can be controlled by the temperature and different atomic configurations at the Co_(2)FeSi/MgO interface.Furthermore,the spin-Seebeck coefficient up to ~150 μV/K is also possible when we select suitable terminations and temperatures.These findings will provide useful insights into how to control the sign and symbol of the TMS ratio and accordingly stimulate the development field of magneto-thermoelectric power and spin caloritronic devices based on the magneto-Seebeck effect in Heusler-based metallic multilayers.展开更多
文摘Solid dispersion(SD)systems have been extensively used to increase the dissolution and bioavailability of poorly water-soluble drugs.To circumvent the limitations of polyvinylpyrrolidone(PVP)dispersions,HPMC E5 was applied in the formulation process and scaling-up techniques,simultaneously.In this study,SD of nimodipine(NMP)and corresponding tablets were prepared through solvent method and fluid bed granulating one step technique,respectively.Discriminatory dissolution media were used to obtain reliable dissolution results.Meanwhile,the stability study of SDs was investigated with storage under high temperature and humidity conditions.Moreover,the solubility of SDs was measured to explore the effect of carriers.The preparations were characterized by DSC,PXRD,and FTIR.Dramatical improvements in the dissolution rate of NMP were achieved by the ingenious combination of the two polymers.Binary NMP/PVP/HPMC-SDs released steadily,while the dissolution of single NMP/PVP-SDs decreased rapidly in water.The fluid-bed tablets(FB-T)possessed a similar dissolution behavior to the commercial Nimotop TM tablets.The characterization patterns implied that NMP existed in an amorphous state in our SDs.Furthermore,the results of stability tests suggested a better stability of the binary SDs.A special cooperative effect of PVP and HPMC was discovered on dissolution characteristics of NMP SDs and tablets,which could be extended to other drugs henceforth.Finally,the bioavailability of FB-T was evaluated in beagle dogs with Nimotop TM as the reference,and the results showed a higher AUC 0–12h value for FB-T.
基金supported by the National Natural Science Foundation of China (Grant No. 12104458)Foshan (Southern China) Institute for New Materials (Grant No. 2021AYF25021)。
文摘Enhancing the tunneling magneto-Seebeck(TMS) ratio and uncovering its underlying mechanism are greatly demanded in spin caloritronics.The magnitude and sign of the TMS effect depend on the type of atom and the stacking order of atoms at the interfaces.Herein,we demonstrate that TMS ratios can be effectively manipulated by altering heterogonous or homogeneous interface through decoration on the CoFeSi(001) surface inserted on the MgO insulating layers.The maximum TMS ratio of pure Co_(2)/O termination is 4565% at 800 K.Notably,the TMS ratio of the FeSi/O termination has two peak values,of which the maximum could reach up to-3290% at 650 K.By comparing two different atom arrangements at the interface,we reveal that the sign and symbol of the TMS ratio can be controlled by the temperature and different atomic configurations at the Co_(2)FeSi/MgO interface.Furthermore,the spin-Seebeck coefficient up to ~150 μV/K is also possible when we select suitable terminations and temperatures.These findings will provide useful insights into how to control the sign and symbol of the TMS ratio and accordingly stimulate the development field of magneto-thermoelectric power and spin caloritronic devices based on the magneto-Seebeck effect in Heusler-based metallic multilayers.
