Commercialization considerations, factors affecting

Since factors other than innovation, such as commercial considerations affecting foreign entry onto the U.S. market, influence the observed patterns, analysis of the national origin of NCEs using the definitions employed here is not a highly sensitive or specific measure of pharmaceutical innovation. However, the observed trends are consistent with the tightening of regulatory policies first in the U.S. and then subsequently abroad. 

Several economic factors affect commercialization of mycoherbicides (54. 64). the ultimate consideration being the projected economic returns from the mycoherbicide. A pathogen that is prone to be unprofitable or unpredictable in this respect, whether due to small market size, cost of production and marketing, competition from other alternative controls, or efficacy, is unlikely to be developed or offered for sale by commercial enterprises. 

Thick vanes can be difficult to bend and fabricate into a final vane assembly. Vanes should be kept as thin as is practical consistent with their intended service. The reduction in flow area coupled with competing considerations of corrosion, erosion and intended service life are the main factors affecting choice of vane thickness. Most vanes in commercial service will have a thickness of 2 to lOrmn. If the vanes are cast, and erosion is a concern, the vane thickness may be intentionally increased in some areas to better withstand erosive attack. 

Factors which may affect the cost of coal upgrading are environmental considerations such as toxicity, hazardous waste disposal, and carcinogenic properties (131). These and other environmental problems from process streams, untreated wastewaters, and raw products would figure significantly into the cost of commercialization. 

A critical factor in the success of a particular separation in an ABS may be the choice of polymer. The polymer not only affects the distribution of the solute between the phases but also has a considerable effect on the physical characteristics of the phases. It may be possible to fine-tune the polymer-rich phase by choosing from a variety of commercially available polymers whose hydrophobicity increases as PEG < Pluronic [block PEG/ polypropylene glycol (PPG) copolymers] < PPG < polytetramethylene glycol (Fig. 3 [36—40]). PPG-2000 is essentially water insoluble (and thus can be utilized neat) but is included for comparison with the ABS systems. The Pluronic polymer used, L64, has a very narrow range of usefulness [41], At low polymer and salt concentrations it forms a monophasic system. If the concentration of polymer and salt is too high, the polymer tends to foam out of solution. 

Since this early work, a very large range of organic acids has been used to prepare cellulose esters, mixed esters, and ethw esters (Rouse, 1965). A typical example of considerable commercial importance is the acetylation of cellulose. As in aU esterifications of macromolecular materials, the accessibility of the hydroxyl groups to the esterilying acid is of prime importance. Reaction (11.1) represents complete esterification, a process that is probably never fuUy achieved. The identification of the esterified products is, therefore, dependent not only on the content of acetyl groups but also on the location of these groups on the macromolecular backbone. Both factors are affected by the method of preparation and the esterification conditions. 

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