Drying as a unit operation in the pharmaceutical industry I. Drying of tablet granulations in fluidized beds
✍ Scribed by M. W. Scott; H. A. Lieberman; A. S. Rankell; F. S. Chow; G. W. Johnston
- Publisher
- John Wiley and Sons
- Year
- 1963
- Tongue
- English
- Weight
- 709 KB
- Volume
- 52
- Category
- Article
- ISSN
- 0022-3549
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✦ Synopsis
The results of drying tests in a fluidized bed and a tray dryer are reported for typical tablet granulations. The data are analyzed to give estimates of total drying times, rates of dryin and overall heat transfer coefficients in each unit. It is concluded that fluidized f e d drying of tablet granulations is at least 1 5 times faster than tray drying procedures. Additional factors, such as capacities per unit floor space, operating costs and thermal efficiencies are reviewed and illustrate other advantages of the fluidization technique.
RYING procedures, like other important unit operations in pharmacy, such as size reduction, solids blending and liquid agitation, have received little attention in pharmaceutical literature. Within recent years, however, growing interest in these pharmaceutical engineering areas has become apparent. This report on fluidized bed drying is one in a series by the authors in this new investigative field of pharmacy.
Fluidization operations, although relatively unexplored in pharmacy, have been firmly established on a broad scale in other industries. Textbooks and other extensive references on fluidization have been published during the past 20 years (1-5). However, relatively few reports have appeared on the applications of fluidized beds to materials of pharmaceutical interest Fluidized bed drying of coal, sand, plastics, and numerous other materials have been discussed in technical literature (11-14). These studies show that high heat transfer, mass transfer and drying rates are obtainable in fluidization systems. As a result of turbulence and excellent interphase contact, uniform bed temperatures are readily achieved. Product temperatures also are controllable over narrow limits within the fluidized bed. These reported advantages would appear to have particular im-(6-10).