Raj Suryanarayanan, PhD
Professor and William & Mildred Peters Endowed Chair, Department of Pharmaceutics
Professor and William & Mildred Peters Endowed Chair, Department of Pharmaceutics
PhD in Pharmaceutics, University of British Columbia
MPharm in Pharmaceutics, Banaras Hindu University
BPharm in Pharmaceutics, Banaras Hindu University
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.
- P. Chakravarty, S. Bhardwaj, L. King and R. Suryanarayanan. Monitoring phase transformations in intact tablets of a,a-trehalose by FT-Raman spectroscopy. AAPS PharmSciTech 10: 1420-1426 (2010).
- P. Sundaramurthi and R. Suryanarayanan. Trehalose crystallization during freeze-drying: implications on lyoprotection. J. Phys. Chem. Lett. 1: 510-514 (2010).
- H. Yamada, K. Terada and R. Suryanarayanan. Non-destructive determination of the coating thickness by X-ray powder diffractometry and correlation with the dissolution behavior of film-coated tablets. J. Pharm. Biomed. Anal. 51: 952-957 (2010).
- P. Sundaramurthi, E. Shalaev and R. Suryanarayanan. “pH Swing” in frozen solutions-consequence of sequential crystallization of buffer components. J. Phys. Chem. Lett. 1: 265-268 (2010).
- P. Chakravarty, R. Berendt, E. Munson, V. Young Jr., R. Govindarajan and R. Suryanarayanan. Insights into the dehydration behavior of thiamine hydrochloride (vitamin B1) hydrates: Part I. J. Pharm. Sci. 99(2): 816-827 (2010).
- E. Lu, S. Ewing, L.A. Gatlin, R. Suryanarayanan and E.Y. Shalaev. The effect of bulking agents on the chemical stability of acid-sensitive compounds in freeze-dried formulations: sucrose inversion study. J. Pharm. Sci. 98(9): 3387-3396 (2009).
- S. Bhattacharya and R. Suryanarayanan. Local mobility in amorphous pharmaceuticals — characterization and implications on stability. J. Pharm. Sci. 98(9): 2935-29553 (2009).
- D.B. Varshney, P. Sundaramurthi, S. Kumar, E.Y. Shalaev, S.-W. Kang, L.A. Gatlin and R. Suryanarayanan. Phase transitions in frozen systems and during freeze-drying: quantification using synchrotron x-ray diffractometry. Pharm. Res. 26: 1596-1606 (2009).
- D.B. Varshney, J.A. Elliott, L.A. Gatlin, S. Kumar, R. Suryanarayanan and E.Y. Shalaev. Sychrotron X-ray diffraction investigation of the anomalous behavior of ice during freezing of aqueous systems. J. Phys. Chem. B 113(18): 6177-6182 (2009).
- I. Dranca, S. Bhattacharya, S. Vyazovkin and R. Suryanarayanan. Implications of global and local mobility in amorphous sucrose and as determined by differential scanning calorimetry. Pharm. Res. 26: 1064-1072 (2009).
- T. Miyazaki, K. Sivaprakasam, J. Tantry and R. Suryanarayanan. Physical characterization of dibasic calcium phosphate dihydrate and anhydrate. J. Pharm. Sci. 98(3): 905-916 (2009).
- E. Lu, N. Rodriguez-Hornedo and R. Suryanarayanan. A rapid thermal method for cocrystal screening. Cryst. Eng. Comm. 10(6): 665-668 (2008).
- K. Chatterjee, E.Y. Shalaev, R. Suryanarayanan and R. Govindarajan. Correlation between chemical reactivity and the Hammett acidity function in amorphous solids using inversion of sucrose as a model reaction. J. Pharm. Sci. 97: 274-286 (2008).
- H. Yamada and R. Suryanarayanan. X-ray powder diffractometry of intact film coated tablets — an approach to monitor the physical form of the active pharmaceutical ingredient during processing and storage. J. Pharm. Sci. 96: 2029–2036 (2007).
- J.S. Tantry, J. Tank and R. Suryanarayanan. Processing-induced phase transitions of theophylline — implications on the dissolution of theophylline tablets. J. Pharm. Sci. 96: 1434-1444 (2007).
- D.B. Varshney, S. Kumar, E.Y. Shalaev, P. Sundaramurthi, S.W. Kang, L.A. Gatlin and R. Suryanarayanan. Glycine crystallization in frozen and freeze-dried systems: effect of pH and buffer concentration. Pharm. Res. 24: 593-604 (2007).
- X. Liao, R. Krishnamurthy and R. Suryanarayanan. Influence of processing conditions on the physical state of mannitol — implications in freeze-drying. Pharm. Res. 24: 370-376 (2007).
- R. Suryanarayanan and A.H.L. Chow. Editorial. J. Pharm. Sci. 96: 945-947 (2007).
- C. Telang and R. Suryanarayanan. Crystallization of cephalothin sodium during lyophilization from tert-butyl alcohol – water cosolvent system. Pharm. Res. 22: 153-160 (2005).
- K. Chatterjee, E.Y. Shalaev and R. Suryanarayanan. Raffinose crystallization during freeze-drying and its impact on recovery of protein activity. Pharm. Res. 22: 303-309 (2005).
- K. Chatterjee, E.Y. Shalaev and R. Suryanarayanan. Partially crystalline systems in lyophilization: I. Use of ternary state diagrams to determine extent of crystallization of bulking agent. J. Pharm. Sci. 94: 798-808 (2005).
- K. Chatterjee, E.Y. Shalaev and R. Suryanarayanan. Partially crystalline systems in lyophilization: II. Withstanding collapse at high primary drying temperatures and impact on protein activity recovery. J. Pharm. Sci. 94: 809-820 (2005).
- R. Surana, A. Pyne, M. Rani and R. Suryanarayanan. Measurement of enthalpic relaxation by differential scanning calorimetry – effect of experimental conditions. Thermochimica Acta 433: 173-182 (2005).
- C. Nunes, A. Mahendrasingam and R. Suryanarayanan. Quantification of crystallinity in substantially amorphous materials by synchrotron X-ray powder diffractometry. Pharm. Res. 22: 1942-1953 (2005).
- X. Liao, R. Krishnamurthy and R. Suryanarayanan. Influence of the active pharmaceutical ingredient concentration on the physical state of mannitol — implications in freeze-drying. Pharm. Res. 22: 1978-1985 (2005).
- S. Debnath, P. Predecki and R. Suryanarayanan. Use of glancing angle X-ray powder diffractometry to depth-profile phase transformations during dissolution of indomethacin and theophylline tablets. Pharm. Res. 21: 149-159 (2004).
- C. Nunes, J. Han, D. Monkhouse and R. Suryanarayanan. Preformulation studies to meet the challenges in the manufacture of betaine solid dosage form. J. Pharm. Sci. 93: 38-47 (2004).
- R. Surana, A. Pyne and R. Suryanarayanan. Effect of aging on the physical properties of amorphous trehalose. Pharm. Res. 21: 867-874 (2004).
- J.D. Meyer, S.J. Bai, M. Rani, R. Suryanarayanan, R. Nayar, J.F. Carpenter and M.C. Manning. Infrared spectroscopic studies of protein formulations containing glycine. J. Pharm. Sci. 93: 1359-1366 (2004).
- R. Surana, A. Pyne and R. Suryanarayanan. Effect of preparation method on physical properties of amorphous trehalose. Pharm. Res. 21: 1167-1172 (2004).
- S.J. Bai, M. Rani, R. Suryanarayanan, J.F. Carpenter, R. Nayar and M.C. Manning. Quantification of glycine crystallinity by near-infrared INIR) spectroscopy. J. Pharm. Sci. 93: 2439-2447 (2004).
- A. Pyne and R. Suryanarayanan. The effect of additives on the crystallization of cefazolin sodium during freeze-drying. Pharm. Res. 20: 283-291 (2003).
- C. Telang, L. Yu and R. Suryanarayanan. Effective inhibition of mannitol crystallization in frozen solutions by sodium chloride. Pharm. Res. 20: 660-667 (2003).
- A. Pyne, K. Chatterjee and R. Suryanarayanan. Crystalline to amorphous transition of disodium hydrogen phosphate during primary drying. Pharm. Res. 20: 802-803 (2003).
- G.G.Z. Zhang, S.Y.L. Paspal, R. Suryanarayanan and D.J.W. Grant. Racemic species of sodium ibuprofen: Characterization and polymorphic relationships. J. Pharm. Sci. 92: 1356-1366 (2003).
- A. Pyne, K. Chatterjee and R. Suryanarayanan. Solute crystallization in mannitol-glycine systems – implications on protein stabilization in freeze-dried formulations. J. Pharm. Sci. 92: 2272-2283 (2003).
- C.E. Botez, P.W. Stephens, C. Nunes and R. Suryanarayanan. Crystal structure of d-D-mannitol. Powder Diffraction 18: 214218 (2003).
- R. Surana, L. Randall, A. Pyne, N. M. Vemuri and R. Suryanarayanan. Determination of glass transition temperature and in situ study of the plasticizing effect of water by inverse gas chromatography. Pharm. Res. 20: 1647-1654 (2003).
- C. Telang, R. Suryanarayanan and L. Yu. Crystallization of D-mannitol in binary mixtures with NaCl: phase diagram and polymorphism. Pharm. Res. 20: 1939-1945 (2003).
- A. Pyne, R. Surana and R. Suryanarayanan. Enthalpic relaxation in frozen aqueous trehalose solutions. Thermochimica Acta 405: 225-234 (2003).
- R. Surana, A. Pyne and R. Suryanarayanan. Solid-vapor interactions: Influence of environmental conditions on the dehydration of carbamazepine dehydrate. AAPS PharmSci Tech 4: (2003) Article 68.
- S. Debnath and R. Suryanarayanan. Influence of processing-induced phase transformations on the dissolution of theophylline tablets. AAPS PharmSci Tech 5: (2003) Article 8.