Pharmaceutical Excipients

Multicolored spheres coming out of broken capsule

Pharmaceutical formulations are often multicomponent, with one or more inactive ingredients added for a specific functionality. It is now largely recognized that the functionality of an excipient may be dependent upon its physical state. However, the processing as well as formulation may alter the physical state of an excipient, thereby affecting its functionality and the quality of the dosage form. We investigate the polymorphic form, degree of crystallinity, and the nature and extent of interaction with other components using X-ray powder diffractometry, thermoanalytical, spectroscopic and microscopic techniques. The goal is to enable development of robust pharmaceutical formulations. We are also interested in identifying new excipients or expanding the utility of existing excipients by controlling their physical state.

Representative publications

  1. Thakral, Seema, Ramprakash Govindarajan, and Raj Suryanarayanan. "Processing‐Induced Phase Transformations and Their Implications on Pharmaceutical Product Quality." Polymorphism in the Pharmaceutical Industry: Solid Form and Drug Development (2018): 329-380.
  2. Kaur, Navpreet, and Raj Suryanarayanan. "Investigating the Influence of Excipients on the Stability of Levothyroxine Sodium Pentahydrate." Molecular Pharmaceutics (2021).
  3. Thakral, Seema, Jayesh Sonje, and Raj Suryanarayanan. "Anomalous behavior of mannitol hemihydrate: Implications on sucrose crystallization in colyophilized systems." International journal of pharmaceutics 587 (2020): 119629.
  4. J. Sonje, S. Thakral, R. Suryanarayanan. t-Butanol enables dual functionality of mannitol: A cryoprotectant in frozen systems and bulking agent in freeze-dried formulations. Mol. Pharm., 17(8), 3075-3086 (2020).
  5. A.A. Thorat, R. Suryanarayanan, Characterization of phosphate buffered saline (PBS) in frozen state and after freeze-drying. Pharm. Res., 36(7), 98 (2019).
  6. A. Sahoo, N.S.K. Kumar, R. Suryanarayanan, Crosslinking: An avenue to develop stable amorphous solid dispersion with high drug loading and tailored physical stability. J Control Release, 311-312, 212-224 (2019).
  7. M.H. Fung, M. DeVault, K.T. Kuwata, R. Suryanarayanan. Drug-excipient interactions: effect on molecular mobility and physical stability of ketoconazole-organic acid coamorphous systems. Mol. Pharm., 15(3), 1052-1061 (2018).
  8. S. Mohapatra, S. Samanta, K. Kothari, P. Mistry, R. Suryanarayanan. Effect of polymer molecular weight on the crystallization behavior of indomethacin amorphous solid dispersions. Cryst. Growth Des., 17(6), 3142-3150, doi: 10.1021/acs.cgd.7b00096 (2017).  
  9. P. Mistry, S. Mohapatra, T. Gopinath, F.G. Vogt, R. Suryanarayanan, Role of the strength of drug-polymer interactions on the molecular mobility and crystallization inhibition in ketoconazole solid dispersions, Mol. Pharm., 12(9), 3339-3350. PMID:  26070543 (2015).