Formulation design is necessary to improve drug solubility, particularly for drugs in Biopharmaceutics Classification System (BCS) classes II and IV. The formulating decision is often affected by the drug's physicochemical properties. To complement the available knowledge, the thermal and structural properties of atovaquone have been investigated. Heat was applied to raw atovaquone to observe the effect of temperature on crystalline polymorphic changes and physical state conversion. Physicochemical properties were assessed through drug content assay, differential scanning calorimetry, X-ray powder diffraction, single-crystal X-ray diffraction and attenuated total reflectance Fourier transform infrared spectroscopy. The surface morphology was observed under a scanning electron microscope. Thermal degradation of atovaquone was confirmed through drug recovery and the sublimating behaviour was observed during the heating process. Understanding the fundamental thermal and structural characteristics of atovaquone plays an important role in designing a stable product of high bioavailability.

中文翻译：

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探索 atovaquone 的固态：晶体还是玻璃？

配方设计对于提高药物溶解度是必要的，特别是对于生物药剂学分类系统 (BCS) II 类和 IV 类中的药物。配方决策通常受药物理化性质的影响。为了补充现有知识，已经研究了 atovaquone 的热和结构特性。对原料 atovaquone 加热以观察温度对结晶多晶型变化和物理状态转换的影响。理化性质通过药物含量测定、差示扫描量热法、X射线粉末衍射、单晶X射线衍射和衰减全反射傅里叶变换红外光谱进行评估。在扫描电子显微镜下观察表面形貌。通过药物回收证实了atovaquone的热降解，并在加热过程中观察到升华行为。了解 atovaquone 的基本热和结构特征对于设计具有高生物利用度的稳定产品具有重要作用。