Evidence for polymorphism in glisentide

The polymorphism of glisentide has been investigated. Three polymorphs (I, II, III) have been prepared by recrystallization from different solvents an d other polymorphic form (IV) was obtained by heating polymorph III at 100 degrees C. In addition, two 1:1 stoichiometric solvates containing carbon t etrachloride and dioxane have been crystallized and finally, an amorphous s olid has been obtained. It has been observed that the polarity of the recry stallisation solvent and its ability to form hydrogen bonds have a great in fluence on the polymorphism of glisentide. The different solid forms of gli sentide have been characterized using X-ray diffraction analysis, different ial scanning calorimetry (DSC), thermogravimetric analysis (TGA), IR spectr oscopy and optical microscopy. The recrystallization of polymorph I in melt ed form II and also the transition of form III-IV have been detected by DSC and X-ray diffraction analysis. (C) 1999 Elsevier Science B.V. All rights reserved.