Characterization of the viscoelasticity of disintegrants by dynamic rheological analysis

Abstract

This study focused on defining a quantitative disintegration index for tablet disintegrants based on a dynamic viscoelastic analysis of the complex disintegration mechanism associated with swelling and wicking. We used an oscillatory rheometer with a serrated-plate measuring system to evaluate the viscoelastic properties of three disintegrants, croscarmellose sodium (CCS), crospovidone (CPV), and corn starch (CS), which were prepared with distilled water at different liquid-to-solid ratios. The swelling and wicking disintegration indices were calculated from the obtained data. The results showed that the three disintegrants could be evaluated by the shear stress and loss tangent as representative dynamic viscoelasticity parameters that changed depending on the water content in the disintegrant preparation. Additionally, the viscoelasticity of CCS and CPV was strongly affected by swelling, whereas that of CS was mainly associated with wicking and water penetration. Furthermore, CPV had the largest swelling disintegration index value, whereas CS showed the largest wicking disintegration index value among the three disintegrants. These results suggested that the disintegration indices based on viscoelasticity established in this study could reflect the disintegration properties inherent to each disintegrant type. Our findings provide valuable guidance for selecting suitable disintegrants in the formulation design.