The effect of thermal and chemical modifications of excipients on the compressional properties of paracetamol tablet formulations including maize, cassava and sweet potato starches as filler-binders

Abstract

The effects of thermal and chemical modifications on the properties of directly compressed paracetamol tablets containing cassava and sweet potato starches were compared with official maize starch. Fresh tubers of the cassava plant, Manihot esculenta Crantz (family Euphorbiaceae) and the sweet potato plant Ipomoea batatas L. Lam (family Convolvulaceae) were obtained and the acetylated and pregelatinized forms of these were prepared using Maize Starch BP as the standard. Paracetamol tablet formulations (500mg) were prepared by direct compression including the starches at various amounts. The compressional properties of the tablets were evaluated using the Heckel, Kawakita and Gurnham equations. Modifications of the starches decreased the Pk (an inverse measure of plasticity) values in the paracetamol formulations at low starch concentrations (10.0% to 25.0%), indicating an increase in the total amount of plastic flow. The Pk values increased at higher starch concentrations (> 50.0%). Tablets containing maize starch showed higher c values when using the Gurnham equation suggesting greater densification. The thermal and chemical modification of the experimental starches improved the compressional properties of the directly compressed paracetamol tablet suggesting that they could be developed for use as pharmaceutical excipients