Particle size decision tree

Particle Size. For substances to be used in certain formulations such as solid or suspension products, the particle size can have a significant effect on dissolution rates, bioavailability, and stability. A decision tree in the guideline provides guidance as to when particle size testing should be considered. 

Scheme 5 Decision tree for the disposition of particle size variation. Source Courtesy of Pharmquest Corporation, Mountain View, California, U.S.A.

A typical large oil shale complex will have a solids flow rate of 500 kg/s, and there is a great incentive to keep the required residence time of shale particles to the minimum possible level (Wishes 1, 2, and 3). This desire will be met if we choose a particle size below 20 mm (Range I) with no heating-up limitations and, further, ensure plug flow of the solids phase. This conclusion is summarized in the form of a decision tree in Fig. 7. 

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