| AVS 65th International Symposium & Exhibition | |
| Applied Surface Science Division | Thursday Sessions |
| Session AS+NS-ThA |
| Session: | Profiling, Imaging and Other Multidimensional Pursuits |
| Presenter: | Jonathan Counsell, Kratos Analytical Ltd, UK |
| Authors: | J.D.P. Counsell, Kratos Analytical Ltd, UK S.J. Coultas, Kratos Analytical Ltd, UK C.J. Blomfield, Kratos Analytical Ltd, UK D.J. Scurr, The University of Nottingham, UK L. Mason, University of Nottingham, UK V. Ciarnelli, Juniper Pharma Services Ltd, UK J.M. Garfitt, Juniper Pharma Services Ltd, UK S. Rigby-Singleton, Juniper Pharma Services Ltd, UK M.R. Alexander, The University of Nottingham, UK M.C. Davies, University of Nottingham, UK C. Moffitt, Kratos Analytical Inc. S.J. Hutton, Kratos Analytical Ltd, UK |
| Correspondent: | Click to Email |
The effects of formulation methodology on the performance of tablets have been studied for decades. Typically tablets consist of the active drug and excipients which influence stability, release rate and binding. HPMC (Hydroxypropyl Methylcellulose) is a hydrophilic polymer commonly used in extended-release tablets as it shows rapid hydration and uniform gel formation. The microstructure of HPMC particles in matrices influences the ability of HPMC to form gel layers after contact with water, thereby affecting release characteristics. While previous studies described the use of Raman spectroscopy as a benchmark method for chemically imaging solid pharmaceutical formulations1, there are relatively few contributions reporting the application of XPS (X-ray Photoelectron Spectroscopy) in this field. New insight into tablet component distribution could be employed in the successful formulation design and development process.
Herein we investigate the novel application of XPS to elucidate the distribution of both drug and excipients species. Parallel XP imaging capabilities will be illustrated and demonstrated for several tablet systems yielding information on particle size, distribution and shape. The use of small-spot XPS provides quantitative and chemical-state information on imaging features. The novel use of argon cluster ion bombardment will be discussed for both cleaning and depth profiling. Peak-fitting, pitfalls and limitations will be explored and compared with other complementary techniques such as ToF-SIMS.
Strachan et al. Journal of Pharmacy and Pharmacology. 2007. 179-192.