Selective Preparation of Metastable Polymorphs Utilizing Inclusion Complexation with Cyclodextrins

利用与环糊精(CyDS)的包合作用，实现了亚稳态的选择性结晶和结晶习性的控制。(1)亚稳型氯丙胺在2-羟基丁基-β-CyD水溶液中沉积，即亚稳型II来自较低的CyD浓度，而最不稳定的第三型来自较高的CyD浓度。(2)当结晶溶剂由水改为2-羟丁基-β-CyD水溶液时，阿司匹林的结晶形态由片状变为针状。结果表明，2-羟基丁基-β-CyD可用于固体药物亚稳态的制备和结晶习性的控制。

The selective crystallization of metastable forms and the control of crystal habits were conducted, utilizing inclusion complexations with cyclodextrins (CyDs). (1) Metastable forms of chlorpropamide were deposited from aqueous 2-hydroxy- butyl-β-CyD solutions, i.e. the metastable form II of the drug from lower CyD concentrations, whereas the most labile form III from higher CyD concentrations. (2) The crystal shape of aspirin was changed from plate to needle crystals, when the crystallizing solvent was changed from water to aqueous 2-hydroxybutyl-β-CyD solutions. The results indicate that 2-hydroxybutyl-β-CyD is useful for preparation of metastable forms and control of crystal habit of solid drugs.