Rustichelli C, Gamberini G, Ferioli V, Gamberini M C, Ficarra R, Tommasini S
Dipartimento di Scienze Farmaceutiche, Università di Modena e Reggio Emilia, Italy.
J Pharm Biomed Anal. 2000 Aug 1;23(1):41-54. doi: 10.1016/s0731-7085(00)00262-4.
Polymorphs of a compound have solid crystalline phases with different internal crystal lattices; in pharmaceuticals, differences due to polymorphism and pseudopolymorphism can affect bioavailability and effective clinical use. The aim of this work was to obtain the different polymorphic modifications of the anticonvulsant drug, carbamazepine, and to characterise them by means of typical structure-sensitive analytical techniques, such as FT-IR spectroscopy, XRPD and DSC. Further investigations were also performed by Hot Stage FT-IR thermomicroscopy, which permitted the visible and spectroscopic characterisation of the polymorphic forms during heating. Our results confirm the existence of three different polymorphic forms for anhydrous carbamazepine: Form III, the commercial one, Form I, obtained by heating Form III and Form II, crystallised from ethanolic solution. Substantial differences were detected among the polymorphs with regard to solid-state properties. Moreover, Hot Stage FT-IR thermomicroscopy proved its analytical potential to characterise the drug's polymorphism.
一种化合物的多晶型物具有不同内部晶格的固体结晶相；在制药领域，多晶型和假多晶型引起的差异会影响生物利用度和有效的临床应用。这项工作的目的是获得抗惊厥药物卡马西平的不同多晶型变体，并通过典型的结构敏感分析技术，如傅里叶变换红外光谱（FT-IR）、X射线粉末衍射（XRPD）和差示扫描量热法（DSC）对其进行表征。还通过热台傅里叶变换红外热显微镜进行了进一步研究，该技术能够在加热过程中对多晶型物进行可视化和光谱表征。我们的结果证实无水卡马西平存在三种不同的多晶型：III型，即市售型；I型，通过加热III型获得；II型，从乙醇溶液中结晶得到。在多晶型物的固态性质方面检测到了显著差异。此外，热台傅里叶变换红外热显微镜证明了其在表征药物多晶型方面的分析潜力。
