Monitoring Granulation Rate Processes Using Three PAT Tools in a Pilot-Scale Fluidized Bed
- 988 Downloads
The purpose of this research was to analyze and compare the responses of three Process Analytical Technology (PAT) techniques applied simultaneously to monitor a pilot-scale fluidized bed granulation process. Real-time measurements using focused beam reflectance measurement (Lasentec FBRM) and near-infra red spectroscopy (Bruker NIR) were taken by inserting in-line probes into the fluidized bed. Non-intrusive acoustic emission measurements (Physical Acoustic AE) were performed by attaching piezoelectric sensors on the external wall of the fluidized bed. Powder samples were collected at regular intervals during the granulation process and characterized offline using laser diffraction, scanning electron microscopy, stereo-optical microscopy and loss on drying method. PAT data comprising chord length distribution and chord count (from FBRM), absorption spectra (from NIR) and average signal levels and counts (from AE) were compared with the particle properties measured using offline samples. All three PAT techniques were able to detect the three granulation regimes or rate processes (wetting and nucleation, consolidation and growth, breakage) to varying degrees of sensitivity. Being dependent on optical signals, the sensitivities of the FBRM and NIR techniques were susceptible to fouling on probe windows. The AE technique was sensitive to background fluidizing air flows and external interferences. The sensitivity, strengths and weaknesses of the PAT techniques examined may facilitate the selection of suitable PAT tools for process development and scale-up studies.
Key wordsacoustic emission FBRM granulation near-infra red PAT
This work was supported by the Science and Engineering Research Council of A*STAR (Agency for Science, Technology and Research).
- 4.M. Levin (Ed.). Pharmaceutical process scale-up, 2nd edn., CRC, New York, 2006, pp. xii.Google Scholar
- 5.J. D. Cutnell, and W. J. Kenneth. Physics, 4th ed., Wiley, New York, 1998, p. 466.Google Scholar
- 16.J. Rantanen, E. Rasanen, J. Tenhunen, M. Kansakoski, J.K. Mannermaa, and J. Yliruusi. In-line moisture measurement during granulation with a four-wavelength near infrared sensor: an evaluation of particle size and binder effects. Eur. J. Pharm. Biopharm. 50:271–276 (2000).PubMedCrossRefGoogle Scholar
- 19.F. J. S. Nieuwmeyer, M. Damen, A. Gerich, F. Rusmini, K. V. D. V. Maarschalk, and H. Vromans. Granule characterization during fluid bed drying by development of a near infrared method to determine water content and median granule size. Pharm. Res. 24:1854–1861 (2007). doi: 10.1007/s11095-007-9305-5.PubMedCrossRefGoogle Scholar
- 20.B. J. Ennis, and J. D. Litster. Particle size enlargement. In R. Perry, and D. Green (eds.), Perry’s Chemical Engineers’ Handbook, 7th edn, McGraw-Hill, New York, 1997, pp. 20–56, 20–89.Google Scholar
- 21.K. P. Hapgood, S. M. Iveson, J. D. Lister, and L. X. Liu. Granulation rate processes. In A.D. Salman, M. J. Hounslow, and J. P. K. Seville (eds.), Handbook of powder technology, volume 11 Granulation, Elsevier, Oxford, 2007, pp. 899, 934–935.Google Scholar
- 23.D. Kunii, and O. Levenspiel. Fluidization engineering, Butterworth-Heinemann, Toronto, 1991.Google Scholar