An Investigation into the use of Creep Viscometry for in Vitro Characterisation of the Raft Forming Properties of tablets Containing Alginic acid and antacid Components

AbstractThe established methods for assessing the strength of rafts formed in-vitro by alginic acid/antacid containing formulations rely on the determination of forces required to disrupt the raft structure. Creep viscometry is proposed as an alternative, non-destructive means of investigating the characteristic parameters of this type of product. Several commercial chewable tablet formulations were investigated using this technique. The instantaneous compliance and the Newtonian viscosity were calculated from the creep compliance curves obtained for these products and were used as raft strength indicators.Differences found in the raft strength parameters of the different products were attributed to interactions between the formulation components. Additional studies conducted on experimental batches established that such interactions could be estimated using this technique. It was concluded that creep viscometry could be usefully employed in investigations of alginate rafts and, possibly, other oral dosag...