Flowability Testing of Directly Compressible Excipients According to British Pharmacopoeia

Flowability and packability of thirteen commercially available, direct compression excipients, Avicel CE-15, Prosolv SMCC HD-90, Prosolv SMCCTM-90, Tablettose 80, Flowlac 100, Cellactose 80, Microcelac 100, Ludipress, Ludipress-LCE, Emcompress, Starch 1500 G, Era Tab and Maize starch-B were examined according to the technical procedure described in the current British Pharmacopoeia. Results revealed unfavorable properties for Ludipress compared to other substances. Ludipress, however, appeared macroscopically to be of extremely pronounced free flowing properties. This contraindication was studied in more detail, proposing to express powder flow in terms of volume per time unit rather than mass time unit (Volume-flowability). Avicel CE-15, Starch 1500 G, Era Tab and Maize starch B exhibited "poor" flow property.