Powder, Compaction and Tableting Properties of Co-processed Silicified Starch

Aims: To evaluate the powder, compaction and tableting properties of co-processed silicified starch for direct compression formulation.
Study Design: The study was designed to co-process cassava starch and colloidal silicon dioxide in a combination ratio of 98:2 using a simple physical method.
Place and Duration of Study: Department of Pharmaceutics and Pharmaceutical Microbiology, Faculty of Pharmaceutical Sciences, Ahmadu Bello University, Zaria, between March 2013 and June 2013.
Methodology: Co-processing of cassava starch and colloidal silicon dioxide was carried out using the method of co-fusion where a dispersion of cassava starch was prepared in distilled water (40% w/w) and mixed with colloidal silicon dioxide prior to thermal treatment at a temperature of 54±2ºC for 15 min in a water bath. The co-processed mixture was dehydrated with ethanol (99%) and tray dried in a Hot air oven at 40ºC for 2 h. It was then kept in an air-tight container for further studies. Powder properties were assessed by measuring the angle of repose, bulk and tapped densities, Carr’s index and Hausner’s ratio. Compaction studies were carried out on tablets compressed at a range of pressures on the Hydraulic Carver Press and analyzed using Heckel and Kawakita equations. Tablets were prepared using chloroquine phosphate as the drug of choice on a Single Stroke Tablet Press by direct compression and evaluated under uniformity of weight, thickness, crushing strength, friability, disintegration and dissolution tests.
Results: The studies revealed an improvement in the functionality of the co-processed excipient with respect to flow, compression and tableting properties when compared to cassava starch.
Conclusion: The silicification of cassava starch by co-processing was able to improve the powder and compaction properties of the excipient suitable for producing tablets by direct compression.