Structures and properties of granules prepared by high shear wet granulation

High shear wet granulation (HSWG) is one of the most widely used processes employed to engineer powders before tableting. This chapter focuses on the evolution of granule structures and its connection to properties of granules prepared by HSWG. The discussion is centered on the material science tetrahedron, which emphasizes the importance of integrated materials science and engineering in solving problems in pharmaceutical product development and manufacturing. Practical topics, i.e., equipment suitable for batch and continuous HSWG processes and end point determination of HSWG, are discussed. The structural evolution of HSWG granules?nucleation, granule growth, and granule breakage?is examined. Influence of several material properties, including initial moisture content, and process parameters, such as massing time, and on the HSWG process is explained. Structural features of granules?surface smoothing, size enlargement, densification, and shape rounding?are discussed in connection with critical powder properties, such as flowability and tabletability. Clear understanding of the structure-property relationships lays a foundation for developing effective strategies to solve the problem of overgranulation and developing robust HSWG processes by formulation approaches.