Congealed material

Melt-induced agglomeration processes are similar to liquid-induced processes except that the binding material is a melt. Therefore, the pellets are formed with the help of congealed material without having to go through the formation of solvent-based liquid bridges. ... 

The US. Pharmacopeia (USP) specification for phenol includes (/) purity is to be no less than 98 wt %, (2) clear solubiUty of 1 part of phenol in 15 parts of water, (2) a congealing temperature to be not lower than 39°C, and (4) a content of nonvolatiles of no more than 0.05 wt %. Commercially, phenol specifications far exceed the USP requirement. Typical commercial phenol specifications are Hsted in Table 5. Higher purity material is required for some apphcations. 

About 5 minutes later, the liquid contents of the beaker are poured cautiously into a 2-1. glass beaker, and this is tipped and rotated slowly so as to spread the congealing mass in a thin film on the beaker walls. When the material in the beakers has cooled, a total of 11. of water is poured into the beakers and the water is stirred well for at least 1 hour (Note 5). The cold suspension is filtered with suction to separate 200-210 g. of an insoluble mixture of lead monoxide and red lead, which is washed on the filter with six 50-ml. portions of water. 

The three overlay plots shown in Fig. 4.11 illustrate another example of how process variations can lead to unexpected changes in material behavior. Consider the instance of a spray congealing process where a mixture of one or more waxes with a melting point below that of the... 

Evidence for these equilibria comes from the Raman spectra, which show an absorption peak (or unresolved peaks), probably attributable to Cu,Clj. Addition of CuCI or Cl causes this peak to increase or decrease as expected by the above equilibria. The system thus probably contains at least four anionic species, and the impurities account for the depression of the melting point. In accordance with this interpretation is the fact that the material is oily and never forms a crystalline solid with a true freezing point, but congeals to a glass. it about 0 °C. 

Rocks, stones, formed of Water and of Earth, are baked in the earth as in a potter s oven, this is why they incline to the earth as if making parts of it. But the precious stones and metals are more favored by celestial influences the first are as the tears of Heaven, and a congealed celestial dew for this reason the Ancients attributed them so many virtues. The sun and the stars seem to have also a particular care for the metals, and one would say that Nature leaves to them the duty to give them their form. The soul of metals is, we may say imprisoned in their material envelope the Philosopher s Fire can draw it from this envelope and make it produce a son worthy of the sun, and an admirable quintessence, which draws Heavens near us. 

Dilute solutions of the materials in alcohol and ether were examined both visually and photographically with a smaller Hilger constant deviation spectrometer. In order to keep the substance at the temperature of liquid air, the solution was placed in a thin walled test tube and congealed by immersion in liquid air in an unsilvered Dewar flask. The test tube was then raised so that about 1 cm. of the gel projected above the surface of the liquid air and the beam of light was passed through this exposed layer. With care, crystallization of the solvent usually could be avoided. 

COAGULUM SPECIFICUM — is the material earthly essence congealed into a dry consistency by Coagulation. 

In this article, typical systems that make use of melt-congealing processes, the equipment and important operating variables used, typical matrix substrate materials, important processing considerations, and the advantages and disadvantages of using these systems are addressed. 

For the formation of solid dispersions by congealing a melt of poorly water-soluble drug and carrier, Ford recommends the following ideal characteristics for the substrate/carrier material ... 

Congealed solids commonly used as carriers and coating materials have been summarized by Ford " and Achanta and are ... 

Hydrogenated Vegetable Oils These primarily consist of the family of stearines. Hydrogenated castor oil (Cutina HR ) has been used as a wax matrix material both in melt-granulation and spray-congealing processes.f ... 

Numerous studies have been reported in the literature that investigate the micro- and macrostructure of the congealed solid and its affect on the dissolution of the active ingredient. The structure of the solid phase formed on congealing is affected by the process by which the material is congealed, the formulation, and the conditions at which the solid product is stored. 

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