**6.3 Hot melt extrusion**

Granules, prolonged-release tablets, transdermal and transmucosal drug delivery devices are all made with hot-melt extrusion shown in **Figure 4**. Rather than using the traditional solvent casting approach, this technique uses heating a polymer to shape it into a film. API and other components are combined in a dry state, then heated, and finally extruded out in a molten form in this procedure. There are no solvent systems involved in these operations. The film is cast from the molten mass that has resulted. The films are then cooled further before being cut to the proper size. Due to the utilisation of extremely high temperatures, this technique is not suited for thermolabile APIs. The casting and drying processes are crucial. Commercial-scale production necessitates the optimization of casting speed and drying time. Lower temperature and shorter residence time of the drug carrier mix, lack of organic solvents, continuous operation, little product waste, good control of operational parameters, and the ability to scale up are all features of this method [66].
