Time-resolved X-ray scattering using synchrotron radiation applied to the study of a polymorphic transition in carbamazepine.
The thermodynamic status of alpha-carbamazepine has been clarified using equilibrium solubility measurements, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), heated X-ray powder diffraction (XRPD), and temperature-controlled X-ray scattering techniques. alpha-Carbamazepine is the least stable of the three well-characterized anhydrous polymorphs of carbamazepine at 25 degrees C. In addition, it was confirmed that alpha-carbamazepine undergoes an exothermic transition to gamma-carbamazepine at 130 degrees C. 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 alpha-carbamazepine has a monotropic relationship with gamma-carbamazepine.
Edwards
A D
AD
Drug Delivery Group, School of Pharmacy, University of Bradford, BD7 1DP, United Kingdom.
Shekunov
B Y
BY
Forbes
R T
RT
Grossmann
J G
JG
York
P
P
D000927:Anticonvulsants / Q000737:chemistry*; D002152:Calorimetry, Differential Scanning; D002220:Carbamazepine / Q000737:chemistry*; D012542:Scattering, Radiation; D014961:X-Ray Diffraction
D000927:Anticonvulsants; D002220:Carbamazepine