Direct compression properties of microcrystalline cellulose and its silicified product

The influence of silicified microcrystalline cellulose (SMCC) on the flow, compaction and tableting properties of metronidazole powder was investigated. The study compared medium grades of both SMCC and standard microcrystalline cellulose (MCC) as direct compressible excipients. The bulk densities, Hausner quotient (H f ), compressibility index (CI) and angle of repose of the formulations were evaluated. Compacts of the metronidazole containing different concentrations of SMCC or MCC (10-30% w/w) were made at compression forces of 20 to 30 KN and evaluated for their physical characteristics. The flow behaviour of the drug was improved in the presence of SMCC. Formulations containing 25% w/w SMCC had lower CI and H f values than those made with 30% w/w MCC. The crushing strength of the compacts increased with concentration of the excipients at all the compression forces used. At similar concentrations of SMCC and MCC, compacts of the formulations containing SMCC exhibited higher crushing strengths. SMCC shows great promise as a filler-binder-disintegrant in direct compression of oral tablet formulations from both mechanical and economic viewpoints. Keywords : metronidazole, tablets, direct compression, Silicified Microcrystalline cellulose, microcrystalline cellulose The East and Central African Journal of Pharmaceutical Sciences Vol. 7(3) 2004: 56-59