Pharmaceutically engineering powders using FHMG: The effects of process parameters and formulation variables

Fluidized hot melt granulation (FHMG) is an innovative granulation process that has distinct advantages over techniques that are typically used in the pharmaceutical industry for powder agglomeration and mixing. The aim of this research was to investigate process and formulation parameters that affect FHMG, in a pharmaceutical context, using Lutrol® F68 (copolymer of polyoxyethylene-polyoxypropylene) as a meltable binder with inert glass ballotini acting as a model pharmaceutical powder. Granulation process parameters investigated were: binder/bulk powder ratio, binder viscosity and granulation time. The experimental data obtained from FHMG were correlated with current granulation theory. De-fluidization occurred at > 10% w/w Lutrol® F68 binder concentration and the resultant granules were highly irregular in shape. Furthermore, the dominant mechanism of granule growth altered from layering to coalescence with increasing binder content. Moreover, a modified growth regime map successfully described experimental data.