Active ingredient melts

Chlorine fluxing of aluminum to remove hydrogen and undesirable metallic impurities has largely been supplanted by fumeless fluxing procedures, which generally employ a low vapor pressure melt of alkaU chlorides containing a small amount of aluminum chloride as the active ingredient. 

Solid formulation mof low melting point of active ingredients... 

Solid formulation of low melting point active ingredients C. Da Cuhna, Z. Negus, J. Porter, A. Thawani... 

PROJECT 4 Solid Formulation of Low Melting Point Active Ingredient... 

Red phosphorus has been used as an effective PBT FR, is non-halogen-based, and very high in active ingredient [55, 56], However, red phosphorus melt blending requires some special considerations. The potential generation of phosphine gas and acidic decomposition products under incorrect melt processing conditions is a concern. Recently, encapsulated grades of red phosphorus have minimized some of these potential issues. Red P blends are also limited in color capability. 

These three steps may be repeated to reach the final structure. For example, microcapsules obtained by spray drying of polymer/active solution may be coated by a melted solution. The first encapsulation insures immobilization and stabilization of the active ingredient, while coating allows control of the level of protection and release. 

Ointments are prepared by melting together the active ingredient with a base, such as petroleum derivative or wax. The powdered drug components are added while stirring and the mixture is cooled. The product then is passed through a roller mill to achieve the particle size range desired for the dispersed solid. 

Chiou and Riegelman defined the term solid dispersion as a dispersion of one or more active ingredients in an inert carrier or matrix at solid state prepared by the melting (fusion), solvent, or melting-solvent method. Dispersions obtained through the fusion process are often called melts, and those obtained by the solvent method are frequently referred to as coprecipitates or coevaporates. Examples include sulfathia-zole-providone (PVP) and reserpine PVP. ... 

Polyanhydrides have been chosen for the preparation of microspheres because of their degradation by surface erosion into apparently non-toxic small molecules.f The mixture of polymer and active ingredient is suspended in a miscible solvent, heated 5°C above the melting point of the polymer and stirred continuously. The emulsion is stabilized by cooling below the melting point until the droplets solidify. 

Polyvinyl acetate is described in the literature as a matrix former in theophylline sustained-release tablets obtained by hot-melt extrusion [646]. In a similar way spray-dried PVAc/Povidone can be applied for the production of tablets and pellets using its excellent flowability. In this case the pulverization of polyvinyl acetate by cryogenic grinding can be avoided and the mixture of the active ingredient with the excipients are applied directly to the melt extruder. 

Form of the active ingredient (dry powder, melt, slurry, or solution), and its amount and nature (hydrophic, hydrophilic, moisture or heat sensitivity, polymorphic changes)... 

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