Non-Parenteral Liquids and Semisolids

On the other hand, the manufacturer may determine that the advantages of process scale-up are compromised by the increased cost of production on a larger scale and/or the potential loss of interest or investment income. Griskey (1) addresses the economics of scale-up in some detail in his chapter on engineering economics and process design, but his examples are taken from the chemical industry. For a more extensive discussion of process economics, see Ref. 2. 

One could also argue that this deficiency in the literature attests to the complexity of the unit operations involved in pharmaceutical processing. If pharmaceutical technologists view scale-up as little more than a ratio problem, whereby 

Large-scale production rate Small-scale production rate 

Furthermore, unit operations may function in a rate-limiting manner as the scale of operation increases. When Astarita (4) decried the fact, in the mid-1980s, that there is no scale-up algorithm which permits us to rigorously predict the behavior of a large scale process based upon the behavior of a small scale process, it was presumably as a consequence of all of these problematic aspects of scale-up. 

A clue to the resolution of the scale-up problem for liquids and semisolids resides in the recognition that their processing invariably involves the 

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