Effect of thermal and chemical modifications of excipients on the compressional properties of paracetamol tablet formulations containing Corn, Cassava and Sweet Potato starches as filler-binders
The effects of thermal and chemical modifications of cassava and sweet potato starches on the properties of directly compressed paracetamol tablets in comparison with official corn starch were determined. Fresh tubers of cassava plant, Manihot esculenta Crantz (family Euphorbiaceae), and sweet potato plant Ipomoea batatas L. Lam (family Convolvulaceae) were sourced and the natural, acetylated and pregelatinised forms of the botanical starches were prepared with Corn starch BP as the standard. Paracetamol tablet formulations (500mg) were prepared by direct compression using the starches at various concentrations. The compressional properties of the tablets were evaluated using Heckel, Kawakita and Gurnham equations. Modification of the starches produced a reduction in 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 with starch modification at higher starch concentrations (≥ 50.0%). Tablets containing corn starch showed higher c values of the Gurnham equation suggesting greater densification. Thermal and chemical modification of the experimental starches improved the compressional properties of directly compressed paracetamol tablet formulations, and thus they can be developed for use as pharmaceutical excipients.