Direct compression with silicified and non-silicified microcrystalline cellulose: study of some properties of powders and tablets

Microcrystalline celluloses Avicel PH-101, PH-102, PH-200 and a 75/25% mixt ure of PH-101 and PH-200 were compared with silicified microcrystalline cel lulose Prosolv SMCC90 as filler-binders for direct compression. A simple mi xture of Avicel PH-102 and colloidal silicon dioxide (Aerosil 200) was also studied. Up to 30% w/w of paracetamol was added in order to properly diffe rentiate between the excipients. Powder and tablet properties could be attr ibuted to macro- and microscopic morphologies of the filler-binders. Intera ction between colloidal silicon dioxide and magnesium stearate explained so me of the differences in tablettability. Silicon dioxide was uniformly dist ributed in Prosolv SMCC90, whereas in the Avicel PH-102/Aerosil mixture, it appeared in agglomerates, unevenly distributed, as assessed by energy disp ersive x-ray spectroscopy (EDS). The differences between Prosolv SMCC90 and the Avicel PH-102/Aerosil mixture were thought to be related to the distri bution of colloidal silicon dioxide. In conclusion, Prosolv SMCC90 was foun d to be worth trying when cohesive, poorly compressible ingredients are for mulated into direct compressed tablets. A simple Avicel PH-102/Aerosil mixt ure or Avicel PH-200 could be selected, especially where flowability is of great importance.