Time-resolved X-ray scattering using synchrotron radiation applied to the study of a polymorphic transition in carbamazepine

✍ Scribed by Anthony D. Edwards; Boris Yu Shekunov; Robert T. Forbes; J. Günter Grossmann; Peter York

• Publisher: John Wiley and Sons
• Year: 2001
• Tongue: English
• Weight: 215 KB
• Volume: 90
• Category: Article
• ISSN: 0022-3549
• DOI: 10.1002/jps.1064

✦ Synopsis

The thermodynamic status of a-carbamazepine has been clari®ed using equilibrium solubility measurements, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), heated X-ray powder diffraction (XRPD), and temperaturecontrolled X-ray scattering techniques. a-Carbamazepine is the least stable of the three well-characterized anhydrous polymorphs of carbamazepine at 258C. In addition, it was con®rmed that a-carbamazepine undergoes an exothermic transition to g-carbamazepine at 1308C. The novel technique of time-resolved simultaneous small-and wide-angle X-ray scattering has been successfully applied to monitor this transition in situ. It was concluded that a-carbamazepine has a monotropic relationship with g-carbamazepine.