Study of the Variables Affecting the Api De-Agglomeration in Solid Formulations

The present paper examines the effects of processing and material (i.e. particle size distribution) variables on the de-agglomeration of pharmaceutical active ingredients (API). A novel shear cell is used to process blends, with API and excipients of varied grades, using different combinations of shear rate (i.e. rpm of the cell) and strain (i.e. length of exposure). The agglomerates are separated from the blends using sieves.

The results show that mean API particle size and strain are the variables that determine the degree of API de-agglomeration, while shear rate does not affect it substantially. All the experiments are repeated to assess the error of the technique, which is reported using error bars in the plots.

The conclusion is that the shear cell is a very useful tool to provide insight for the development of mixing process. API with smaller particle sizes lead to a larger proportion of agglomerated material. Strain is the main variable leading to de-agglomeration.