晶型药物是指药效成分以特定晶型状态存在的固体药物。随着人们对晶型药物认识的不断深入，发现药物晶型的微小改变不但引起药物理化性质的改变，而且药物在体内的生物活性及临床效果也可能不同。因此,晶型药物已成为结晶化学、药效学及药代动力学等多学科交叉研究的热点领域。本项目拟以瑞巴派特、薯蓣皂苷元和坎地沙坦等三种水溶性差、生物利用度低的药物分子为研究对象，通过晶体工程学原理和方法对三种药物的晶型进行设计，在尽可能多地合成三种药物分子的晶型并获得单晶结构数据的基础上，从中筛选出具有高生物利用度和一定稳定性的优势晶型，探索药物分子构型、构象、堆积方式及氢键等结构因素与药代动力学中的生物利用度之间的构动关系及其演变规律，为揭示晶型药物体内吸收机制，难溶药物生物利用度的改善提供技术支撑。本项目的实施不仅对丰富和发展晶体工程学、超分子化学具有重要的理论意义，而且对推进新晶型药物的设计与开发也具有良好的应用。

Polymorphic drugs mean solid drugs exsiting in the given crystal form. With the deeper understanding of polymorphic drugs, people find that when small structure change occurs for the drug, not noly their physical and chemical properties but also their bioactivities and clinical results may be different. Therefore, polymorphic drugs have become a hot, multidisciplinary research field involving crystallochemistry, pharmacodynamics and pharmacokinetics. Herein this project, three drugs rebamipide, diosgenin and candesartan etc. with the shortcoming of poor solubility and low bioavailability are studied and their new crystal forms are designed according to the principles and methods of crystal engineering. And on the basis of obtaining their as many crystal forms as possible and single crystal structure data, optimal crystal forms with improved bioavailability and suitable stability are selected. The project aims to explore the structure-pharmacokinetics relationship between drug crystal structure factor including configuration, conformation, stacking mode, hydrogen bond etc. and bioavailability in pharmcokinetics and it is aimed at providing the scientific basis and technological support for the revelation of absorption mechanism of polymorphic drugs and improving bioavailability of poor solubility drugs. It is of both great scientific and practical importance to enrich and develop crystal engineering and supermolecular chemistry and to advance the design and development of new polymorphic drugs.