Spray particle formulation

Figure 2 shows scanning electron microscope pictures, at 300X magnification, of the two formulations. The spray dry formulation shows an irregular, Inconplete shell around the particle. 

Scott, M.W. Robinson, M.J. Pauls, J.F. Lantz, R.J. Spray congealing particle size relationships using a centrifugal wheel atomizer. J. Pharm. Sci. 1964, 53, 670-675. Cusimano, A.G. Becker, C.H. Spray-congealed formulations of sulfaethyliadiazole (SETD) and waxes for prolonged-release medication. J. Pharm. Sci. 1968, 57, 1104-1112. 

The dissolving and dispersing behavior of complexly formulated particles has to be measured in laboratory devices either by optical particle analysis, or by chemical analysis of dissolved matter within the solution or suspension. For that purpose, the spray particles are positioned in baskets within stirred containers, and the light extinction is measured in the suspension or the concentration of dissolved chemical species is recorded versus time (Schubert, 1990 Hogekamp and Pohl, 2004). Similar systems are applied to assess the release functions of pharmaceuticals (Martin and Leuenberger, 2002 Schultz and Kleinebudde, 1997). 

General Principles of Particle Formulation in Spray Fluidized Beds... 

The previous discussion pointed out that various material properties have a more or less strong influence on particle formulation in spray fluidized beds. Process conditions, such as the spraying rate, gas temperature, or the mass flow rate of the fluidization gas, can also very significantly affect the properties of the resulting particles. This aspect will be illustrated in the present section by means of selected examples. 

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