Polymorphic phase transitions in carbamazepine and 10,11-dihydrocarbamazepine

DOI: 10.1002/chem.201802368

Authors: Alexander E. Clout (University College London) , Asma B. M. Buanz (University College London) , Simon Gaisford (University College London) , Gareth R. Williams (University College London)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Chemistry - A European Journal

State: Published (Approved)
Published: July 2018
Diamond Proposal Number(s): 10503 , 12735

Abstract: Temperature‐induced phase transitions in carbamazepine (CBZ) and 1,10‐dihydrocarbamazepine (DHC) were studied by simultaneous differential scanning calorimetry ‐ X‐ray diffraction in this work. The transitions generally involve a transitional melt phase which is quickly followed by recrystallisation. The expansions of the unit cell as a function of temperature could be quantified and allow us to determine a directional order of stability in relation to the lattice constants. Dihydrocarbamazepine form II undergoes a conversion to form I by a localized melt phase. Carbamazepine (CBZ) form IV converts to form I at 182 °C, by either a solid‐solid pathway or a localised intermediate melt phase. CBZ form II converted to form I at 119 °C by a pathway that appears to have included some melting, and form III underwent a part melt‐recrystallisation and a part sublimation‐recrystallisation to form I.

Journal Keywords: Phase transitions; pharmaceutical materials; thermal analysis; synchrotron X-ray diffraction; hyphenated techniques

Subject Areas: Chemistry, Medicine


Instruments: I12-JEEP: Joint Engineering, Environmental and Processing

Added On: 25/07/2018 09:21

Documents:
chem.201802368.pdf

Discipline Tags:

Chemistry Organic Chemistry

Technical Tags:

Diffraction