Co-amorphous technology to improve dissolution and physical stability of silybin / 中国中药杂志

The present study explored the effect of co-amorphous technology in improving the dissolution rate and stability of silybin based on the puerarin-silybin co-amorphous system prepared by the spray-drying method. Solid-state characterization was carried out by powder X-ray diffraction(PXRD), polarizing microscopy(PLM), Fourier transform infrared spectroscopy(FT-IR), differential scanning calorimetry(DSC), etc. Saturated powder dissolution, intrinsic dissolution rate, moisture absorption, and stability were further investigated. The results showed that puerarin and silybin formed a co-amorphous system at a single glass transition temperature which was higher than that of any crude drug. The intrinsic dissolution rate and supersaturated powder dissolution of silybin in the co-amorphous system were higher than those of the crude drug and amorphous system. The co-amorphous system kept stable for as long as three months under the condition of 40 ℃, 75% relative humidity, which was longer than that of the single amorphous silybin. Therefore, the co-amorphous technology could significantly improve the dissolution and stability of silybin.

Investigation on Correlation of Phase Behavior and Stability of Curcumin Self-nanoemulsion with Different Drug Loading After in Vitro Dispersion / 中国实验方剂学杂志

Objective:To investigate the relationship between phase behavior of curcumin （CUR） from self-nanoemulsion drug delivery system （SNEDDS） and stability of the formed nanoemulsion in artificial gastrointestinal fluid. Method:The growth rate of precipitation after dispersion of CUR-SNEDDS was expressed by the change tendency of CUR supersaturation-time curve. The effect of drug loading on crystal nucleation and growth was investigated by ultraviolet-visible spectrometry and polarized light microscope， respectively. X-ray powder diffraction （XRD） and differential scanning calorimetry （DSC） were used to analyze the precipitation forms of CUR-SNEDDS with different drug loading in artificial gastrointestinal fluid. At the same time， the effect of drug loading on the quality stability of nanoemulsion formed by CUR-SNEDDS in artificial gastrointestinal fluid was investigated. Result:In the artificial gastrointestinal fluid， with the increase of drug loading， the area under the supersaturation-time curve of CUR was increased （100% drug loading≈90% drug loading>75% drug loading）， the crystallization nucleation and growth rate were accelerated （100% drug loading>90% drug loading>75% drug loading）， the amorphous proportion in the precipitation composition decreased， the nanoemulsion droplets adhered and distributed unevenly， the particle size and dispersivity were increased. Conclusion:High drug loading promotes the nucleation and growth of crystals， and increases the proportion of crystal forms in the precipitation composition， which leads to the decrease in the stability of the formed nanoemulsion. Therefore， it is suggested that the drug loading of CUR-SNEDDS needs to be controlled below 90%.