Advantages And Disadvantages Of Hot Melte Extrusion
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In hot melt extrusion, materials are heated, melted and dispersed to be cooled. This process is not suitable for thermolabile products, and the excipients should be miscible in the molten state . Large size particles are produced by hot melt extrusion. Process parameters such as temperature, pressure and mixing rate determines product properties like density, particle morphology, size and size distribution. Table 2 lists the advantages and disadvantages of hot melt extrusion technique [2,5].
The process typically consists of three phases (figure cxxx). First, feeding phase in which excipients enters the heating chamber. Second, the excipients melts and a screw allows its mixing and transfer into the extrusion station. Finally, Extrusion in which the extruder controls the shape and size of the extrudate once is cooled down and cut [12,13].
Co-milling is very efficient in dispersing and homogenizing excipients, it also reduced partiele size in aqueous media. This technique…show more content… The cooling rate has a direct effect on the co-crystal’s size, growth and shape. After co-crystals production, they are then filtered and washed to eliminate impurities. Finally, the crystals are dried, milled and sieved to reduce their particle size .
Co-crystallization involves two main steps: nucleation (the material starts its crystallization process on a specific site) which can occur in labile zone that is a zone not optimal for crystal growth, and second the crystal or co-crystal growth. The solid crystals can be formed from liquid, melt or gas, and are more stable than the individual initial materials and held together by non-covalent forces. Compared to the initial material, the co-crystal has a different crystallinity, solubility and mechanical properties