Mechanism of Action of Starch as a Tablet Disintegrant IV: Effect of Medicaments and Disintegrants on Mean Pore Diameter and Porosity

Abstract

Two full factorial experiments were designed. The first one had three disintegrants (corn starch, cation-exchange resin, and waxy maise starch) at four different concentrations (0, 5, 10, and 15%), and three levels of compression pressure (1000, 3000, and 6000 psig.) with aspirin. The second experiment had four different medicaments (aspirin, MgO, Mg trisilicate, and salicylamide), three levels of pressure, and corn starch at the four concentration levels. Mean pore diameter, porosity, and disintegration time were the measured parameters. Mean pore diameters were measured in an air permeability apparatus and calculated from: ▪Dried corn starch with 2% moisture was compared to regular corn starch containing 11% moisture. The effect of colloidal silicon dioxide was also studied. Broad generalities as to the effect of the variables on the measured parameters could not be made because of the complexities and interactions of the variables; i.e., disintegrant concentration effect on mean pore diameter varied with the medicament used, the pressure level, and even the specific disintegrant. Neither the effect on mean pore diameter nor porosity was found to be the mechanism of action of starch and other disintegrants in disintegrating tablets under the conditions of these experiments.