Solid State Pharmaceuticals

White tablets and a molecular structure on a blue background.

The majority of drugs are administered as solid dosage forms. Our physical characterization studies, of both drugs and excipients, are aimed at improving the quality and robustness of pharmaceutical products. We are also interested in understanding the impact of pharmaceutical processing and formulation components on phase behavior, and in turn, the effect on product stability and performance. We also aim to identify the molecular basis of such transformations so as to develop robust mitigation strategies.  While the active ingredient is of predominant concern, there are cases where phase transitions of excipients may be of relevance and importance. We employ a battery of analytical techniques, specifically, differential scanning calorimetry, thermogravimetric analysis, gravimetric water sorption, powder X-ray diffractometry (both laboratory and synchrotron sources), microscopy, and spectroscopy (IR, NMR and dielectric) for comprehensive material characterization.

Further Reading

  1. S. Thakral, R. Govindarajan, R. Suryanarayanan. Processing‐Induced Phase Transformations and Their Implications on Pharmaceutical Product Quality. In R. Hilfiker and M. von Raumer (Eds.), Polymorphism in the Pharmaceutical Industry: Solid Form and Drug Development, 329-380. Wiley (2018).
  2. N. Kaur, R. Suryanarayanan. Investigating the Influence of Excipients on the Stability of Levothyroxine Sodium Pentahydrate. Mol Pharm, 18(7), 2683-2693 (2021).
  3. N. Kaur, V.G. Young Jr., Y. Su, R. Suryanarayanan. Partial dehydration of levothyroxine sodium pentahydrate in a drug product environment: Structural insights into stability. Mol Pharm, 17(10), 3915-3929 (2020).
  4. S. Thakral, J. Sonje, R. Suryanarayanan. Anomalous behavior of mannitol hemihydrate: Implications on sucrose crystallization in colyophilized systems. Int J Pharm, 587, 119629 (2020).
  5. S. Koranne, R. Lalge, R. Suryanarayanan. Modulation of Microenvironmental Acidity: A Strategy to Mitigate Salt Disproportionation in Drug Product Environment. Mol Pharm, 17(4), 1324-1334 (2020).
  6. N. Kaur, N.K. Duggirala, S. Thakral, R. Suryanarayanan. Role of lattice disorder in water-mediated dissociation of pharmaceutical cocrystal systems. Mol Pharm, 16(7), 3167-3177 (2019).
  7. S. Koranne, J.F. Krzyzaniak, S. Luthra, K.K. Arora, R. Suryanaryananan. Role of coformer and excipient properties on the solid-state stability of theophylline cocrystals. Cryst Growth Des, 19(2), 868-875 (2019).
  8. N.K. Thakral, S. Thakral, G.A. Stephenson, R. Sedlock, R. Suryanarayanan. Compression-induced polymorphic transformation in tablets: Role of shear stress and development of mitigation strategies. J Pharm Sci, 108(1), 476-484 (2019).