Temperature-Induced Phase Transitions in Carbamazepines

  • ChemPubSoc Europe Logo
  • Author: Chemistry – A European Journal
  • Published Date: 04 October 2018
  • Source / Publisher: Chemistry – A European Journal/Wiley-VCH
  • Copyright: Wiley-VCH Verlag GmbH & Co. KGaA
thumbnail image: Temperature-Induced Phase Transitions in Carbamazepines

Related Societies

Pharmaceutically active compounds can exist in different physical forms, which have different physicochemical properties, e.g., solubility or dissolution rate. These properties have a significant influence on the effect of the compound in a drug. Knowledge about the physical form of an active ingredient is, thus, important for its use in medicine.


Gareth Williams, Simon Gaisford, and colleagues, University College London, UK, have used simultaneous differential scanning calorimetry (DSC) and synchrotron X-ray diffraction (XRD) to explore the phase transitions in two related pharmaceutical materials: the anti-seizure drug carbamazepine (pictured) and its derivative 10,11-dihydrocarbamazepine.


Usually, such phase transitions are studied using only DSC, which does not give structural information. XRD can do this, but normally takes a considerable time to record a diffraction pattern, which makes it difficult to study short‐lived phases. The team showed that a simple modification to a standard lab DSC instrument allows it to be mounted on a synchrotron X‐ray source, which allows diffraction patterns to be obtained in as little as 2 s.


The conversions between the different physical forms of the two compounds were previously thought to be solid–solid transitions. The team proved this assumption wrong and showed that the conversion involved at least some melting, followed by recrystallization. According to the researchers, the simultaneous use of DSC and XRD to analyze a single sample gives new insight into phase transitions which are important for pharmaceutical chemistry.


 

Article Views: 440

Sign in Area

Please sign in below

Additional Sign In options

Please note that to comment on an article you must be registered and logged in.
Registration is for free, you may already be registered to receive, e.g., the newsletter. When you register on this website, please ensure you view our terms and conditions. All comments are subject to moderation.

Article Comments - To add a comment please sign in

Bookmark and Share

If you would like to reuse any content, in print or online, from ChemistryViews.org, please contact us first for permission. more


CONNECT:

ChemistryViews.org on Facebook

ChemistryViews.org on Twitter ChemistryViews.org on YouTube ChemistryViews.org on LinkedIn Sign up for our free newsletter


A product of ChemPubSoc Europe (16 European Chemical Societies)and Wiley-VCH