Application of Silicified Microcrystalline Cellulose in the formulation of Metronidazole Tablets

Abstract

The influence of Silicified Microcystalline Cellulose on the powder, compaction and tableting properties of metronidazole was investigated. The study employed a medium grade of Silicifed Microcystalline Cellulose, commercially available as Prosolv SMCC<R) 90. Prosolv is a product, which resulted from co-processing of Microcrystalline Cellulose with colloidal Silicon dioxide. A similar grade of regular Microcystalline Cellulose (Emcocel) was used as reference. The bulk densities, Hausner quotient (Hf), Compressibility Index (CI) and angle of repose of formulations containing the drug and polymers were evaluated. Compacts of the amoebicidal drug, containing different concentrations of Prosolv or Emcocel within the range of 10 to 30 % w/w were made at compression forces between 20 to 30 KN. The compression and friability profiles of the compacts were evaluated. The flow behaviour of the DrugrProsolv mixtures was improved, with increase in poured bulk density of the drug, while angle of repose and compressibility index parameters decreased. Metronidazole formulations containing 25 % w/w of Prosolv had lower CI and Hf values than those made with 30 % w/w Emcocel. The crushing strength of the compacts increased with concentration of the polymers at all the compression forces used. At similar concentrations of the polymers, compacts of the formulations containing Prosolv exhibited higher crushing strength at the same compression pressure. Compacts of metronidzole containing 20 to 25 % of Prosolv exhibited disintegration and friability profiles comparable to those made with 30 % Emcocel. Prosolv may serve as a first choice excipient in direct compression formulation of metronidazole tablets, especially from mechanical and economic viewpoints.