Aceves-Hernandez J M, Nicolás-Vázquez I, Aceves F J, Hinojosa-Torres J, Paz M, Castaño V M
Facultad de Estudios Superiores Cuautitlán, Universidad Nacional Autónoma de México, Av. 1 de Mayo s/n, Col. Sta. Ma. Las Torres, Cuautitlán Izcalli, Estado de México, México 54740, Mexico.
J Pharm Sci. 2009 Jul;98(7):2448-63. doi: 10.1002/jps.21626.
Thermal analysis of indomethacin alpha and gamma polymorphs presents a temperature transition at 429.2 and 435.8 K, respectively, although with X-ray diffraction or near infra-red spectroscopy phase transformations were not registered. DSC method for the indomethacin amorphous solid shows an endothermic event; however, the conformational analysis at higher temperature shows a rotational change which may explain such endothermic peak. By heating the gamma polymorph at 483 K (210 degrees C) for 30 min and then quenching into liquid nitrogen the amorphous solid was obtained. The alpha form shows the highest intrinsic dissolution rate, while the lowest rate was for the amorphous indomethacin. Theoretical calculations (ab initio, Hartree-Fock and density functional theory, DFT) indicate that the double interaction is responsible for the observed difference in solubility.
吲哚美辛α和γ多晶型物的热分析分别在429.2 K和435.8 K出现温度转变，尽管通过X射线衍射或近红外光谱未记录到相变。吲哚美辛无定形固体的差示扫描量热法（DSC）显示出一个吸热事件；然而，在较高温度下的构象分析显示出一种旋转变化，这可能解释了这种吸热峰。通过在483 K（210℃）下将γ多晶型物加热30分钟，然后骤冷至液氮中，得到了无定形固体。α晶型显示出最高的固有溶解速率，而无定形吲哚美辛的溶解速率最低。理论计算（从头算、哈特里-福克和密度泛函理论，DFT）表明，双重相互作用是观察到的溶解度差异的原因。
