University of Otago, New Zealand


Te Tari Hua-Ruanuku

Gordon Group Researchers

Clare Strachan
Novel spectroscopic techniques to investigate drug crystallinity and polymorphism

Clare submitted her PhD in 2005. Her project involved polymorphism. Clare worked as a researcher in Finland before returning to Otago to take up a lecturing post in the School of Pharmacy.

Project Summary

Polymorphism and variations in the degree of crystallinity in a pharmaceutical substance may exhibit physicochemical differences that impact at therapeutic, manufacturing, commercial and legal levels. Therefore, polymorphism and crystallinity changes must be monitored in drug and dosage form development. Spectroscopic analysis has become increasingly popular to monitor crystallinity and polymorphism due to its speed, minimal sample preparation, and adaptability for online use. This project investigates the potential several novel spectroscopic methods and associated techniques to investigate and quantify drug crystallinity and polymorphism. The project is divided into four main areas:

  1. The use of second harmonic generation to detect and quantify drug crystallinity and polymorphism.
  2. The use of ab initio calculations to predict vibrational spectra and interpret spectral and packing differences of polymorphs.
  3. The use of Raman and IR spectroscopy and multivariate analysis to improve quantitation of drug crystallinity and polymorphism.
  4. The use of terahertz pulsed spectroscopy (TPS) to quantify polymorphism and crystallinity.

Calculated and actual spectra of carbamazepine polymorphs