Raj Suryanarayanan, PhD

Research Summary

A large fraction of pharmaceutical products are administered as solids. We are interested in the material science of pharmaceutical solids with a specific emphasis on their physical characterization. In drugs and excipients we investigate the polymorphic form, degree of crystallinity, and the nature and extent of interaction with water.

In addition to X-ray powder diffractometry, thermoanalytical, spectroscopic and microscopic techniques are used for this purpose. We are specifically interested in monitoring and quantifying phase transitions at various stages of pharmaceutical processing. While the active ingredient is of predominant concern, there are cases where phase transitions of excipients may be of relevance and importance. The goal is to ensure reproducible and predictable performance of solid dosage forms with minimum batch-to-batch variations.

Our current research interests are in the following areas: (1) Monitor phase transitions during the entire freeze-drying cycle using specialinstrumentation built in-house. The ultimate goal is the optimization of the freeze-drying cycles of protein pharmaceuticals. (2) Simultaneous quantification of reactant, product, and intermediate phases of very rapid reactions (time resolution of 40 msec) using high intensity X-rays. (3) Use of a microdiffractometer to map tablet surfaces and also to characterize specific regions of a powder bed (or of a tablet). (4) Identify new excipients or modify the physical state of current excipients with the object of expanding their utility in freeze-dried formulations.

For an updated list of publications, visit Professor Sury's Google Scholar and ResearchGate profiles.