A new method for the control of size of pellets in the melt pelletization process with a high shear mixer
Heng, Paul Wan Sia
Wong, Tin Wui
Shu, Jian Jun
Wan, Lucy Sai Cheong
Date of Issue1999
School of Mechanical and Aerospace Engineering
The control of the melt pelletization process in an 8-l high shear mixer using specific energy consumption of the impeller motor was studied. Lactose was used as the bulk material with polyethylene glycol 3000 as a meltable binder. The effects of binder concentration, mean particle size of bulk material and post-melt impeller speed on the relationship of specific energy consumption and pellet growth were examined. Specific energy consumption was found to be a suitable tool for monitoring the melt pelletization process, and specific energy consumption correlated well with pellet growth. The mean size of the pellets formed becomes correspondingly larger with increasing specific energy consumption. Concerning the impeller speed, specific energy consumption is more useful as a tool for end-point control of the process than post-melt mixing time. Similar size pellets can be obtained with comparable specific energy consumption, independent of the impeller speed. The control of pellet size requires a correlation between pellet growth and specific energy consumption that is established for the formulation and process conditions used. For this purpose, mathematical modelling of the pellet growth process is presented. The predictions of pellet growth by the mathematical model are in agreement with the experimental findings.
Chemical & pharmaceutical bulletin
© 1999 Pharmaceutical Society of Japan. This paper was published in Chemical and Pharmaceutical Bulletin and is made available as an electronic reprint (preprint) with permission of Pharmaceutical Society of Japan. The paper can be found at the following official DOI: [http://dx.doi.org/10.1248/cpb.47.633]. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law.