Department of Industrial and Physical Pharmacy, Purdue University, 575 Stadium Mall Drive, West Lafayette, Indiana 47907, USA.
Pharm Res. 2010 Jul;27(7):1377-89. doi: 10.1007/s11095-010-0129-3. Epub 2010 May 18.
To gain a better understanding of the physical state and the unusual thermal behavior of milled griseofulvin.
Griseofulvin crystals and amorphous melt quench samples were milled in a vibrating ball mill for different times and then analyzed using differential scanning calorimetry (DSC) and powder X-ray diffraction (PXRD). Modulated DSC (mDSC) and annealing studies were done for the milled amorphous samples to further probe the effects of milling.
Milling of griseofulvin crystals results in decrease in crystallinity and amorphization of the compound. A double peak is seen for crystallization in the DSC, which is also seen for the milled melt quench sample. Both enthalpy and temperature of crystallization decrease for the milled melt quenched sample. Tg is visible under the first peak with the mDSC, and annealing shows that increasing milling time results in faster crystallization upon storage.
Milling of griseofulvin results in the formation of an amorphous form and not a mesophase. It increases the amount of surface created and the overall energy of the amorphous griseofulvin, which leads to a decreased temperature of crystallization. The two exotherms in the DSC are due to some particles having nuclei on the surface.
更好地了解粉碎灰黄霉素的物理状态和异常热行为。
将灰黄霉素晶体和非晶熔体淬火样品在振动球磨机中研磨不同时间,然后使用差示扫描量热法(DSC)和粉末 X 射线衍射(PXRD)进行分析。对研磨的非晶样品进行调制差示扫描量热法(mDSC)和退火研究,以进一步探究研磨的影响。
灰黄霉素晶体的研磨导致结晶度降低和化合物非晶化。DSC 中观察到结晶出现双峰,研磨的熔体淬火样品也出现双峰。研磨的熔体淬火样品的结晶焓和结晶温度均降低。mDSC 下在第一峰下可见 Tg,退火表明,随着研磨时间的增加,储存时结晶速度加快。
灰黄霉素的研磨导致形成非晶态而不是介晶态。它增加了表面的形成和非晶灰黄霉素的总能量,从而降低了结晶温度。DSC 中的两个放热峰是由于一些颗粒表面有核。