Twin-screw granulation and high-shear granulation: the influence of mannitol grade on granule and tablet properties

Granule structure has a key influence on tablet critical quality attributes. The ability to control this structure through excipient choice is an important part of formulation development. Mannitol is a popular diluent and the choice of input grade has been shown to impact granule properties. Allopurinol formulations containing two grades of mannitol (Pearlitol 160C and 200SD) were prepared by wet-granulation (twin-screw and high-shear) at different liquid / solid ratios (0.3 and 0.6 g/g). The particle and bulk properties were characterised by a range of techniques and linked to flow performance and tablet tensile strength during compression on a rotary tablet press.

During granulation, 200SD underwent a polymorphic transition from a mixture of α and β to predominantly β. This transition was accompanied by a morphology change. Mannitol needles were formed, giving more porous granules with a higher specific surface area, which led to poorer flow properties but higher tablet tensile strength. This study concludes that understanding the effect of mannitol grade is a crucial part of formulation selection.

More on influence of mannitol grade in Twin-screw  and high-shear granulation

Andrew Megarry, Agnes Taylor, Aida Gholami, Håkan Wikström, Pirjo Tajarobi, Twin-screw granulation and high-shear granulation: The influence of mannitol grade on granule and tablet properties, International Journal of Pharmaceutics,
Volume 590, 2020, 119890, ISSN 0378-5173, https://doi.org/10.1016/j.ijpharm.2020.119890.