What is recognized as the most common method for dry granulation?

Roller compaction is recognized as the most common method for dry granulation because it effectively converts powders into granules without the use of liquid binders. In this process, powder is fed between two rollers that compress the powder into a dense sheet or ribbon. This ribbon is then milled into granules of the desired size.

The advantages of roller compaction include its ability to handle a wide range of materials, including those that are moisture-sensitive, and its scalability for large-scale production. Additionally, the process enhances the flowability and compressibility of the powders, making it suitable for subsequent tablet formation.

Other methods mentioned, such as tablet punching, are focused on the final stage of tablet formation rather than granulation itself. Fluidized bed drying is primarily a drying process, not a granulation method, as it involves the use of hot air to remove moisture from granules. Extrusion, while a valid process in pharmaceutical manufacturing, often involves wet massing and is less commonly associated with dry granulation compared to roller compaction. Thus, roller compaction stands out as the most prevalent and effective method for dry granulation in pharmaceutical sciences.