Small-scale characterization of wet powder masses suitable for extrusion-spheronization

The method of compresso-rheology with an Instron 5567 was used for flow assessment of wet powder mass in order to improve its formulation. In our experiments, the method was efficient for selection of the excipient (Avicel CL611) able to improve the extrusion behavior of the high-dose wet powder mass. The method also allowed the determination of the minima and maxima of the wetting agent volume necessary to identify the correct moisture content for extrusion (20%). The results were not discriminative for the choice of the Avicel CL611 amount in the formulae even if an average amount necessary to improve extrudability of the active ingredient could have been estimated at about 10%. Nevertheless, this method appeared to be a rapid and easy small-scale method for studying wet powder mass, cause only a few grams of solids are required, this rheometer should prove useful in formulation research.