Direct compression of ibuprofencontaining powder blends:Influence of the ibuprofen grade on the flow and compaction properties of an ibuprofen tablet formulation

Ibuprofen powders exhibit poor flowability, poor compactability, and ibuprofen tablets show a high tendency to stick to punch surfaces during tablet manufacture. Several ibuprofen grades are available on the market. The compaction properties of ibuprofen have been extensively investigated by several authors. However, a comparison of various ibuprofen grades with regard to flow and compaction properties has not been made so far. Therefore, the objective of the present study was to investigate the influence of the ibuprofen grade on the flowability of powder blends and on the compaction properties of tablets prepared by direct compression. Six different ibuprofen grades from three commercial suppliers were compared. A model tablet formulation containing 70% of the drug was evaluated with regard to the flow and deformation characteristics, the sticking tendency of the tablets as well as the tablet properties such as tablet disintegration and drug dissolution. It could be shown that flow and compaction properties of the investigated powder blends were considerably affected by the ibuprofen grade. Both flow and compaction properties were found to be strongly dependent on the mean particle size of the respective ibuprofen grade. Powder blends consisting of ibuprofen grades with larger particles showed appropriate flowability and compactability, and the properties of resulting tablets were acceptable.