Superior disintegrating properties of calcium cross-linked Cassia fistula gum derivatives for fast dissolving tablets

The present investigation was aimed at evaluating the feasibility of using calcium salts of carboxymethylated (CaCOG) or carbamoylethylated (CaCEG) derivatives of Cassia fistula gum as superdisintegrant while formulating fast disintegrating tablets (FDTs) exhibiting lowest disintegration time (DT) at highest mechanical strength. FDTs prepared with CaCOG (5%, w/w) or CaCEG (5%, w/w) were directly compressible and showed superior disintegrating property due to decreased water sorption time, increased particle packaging index, without any significant change in swelling index and effective pore radius. The mechanisms of superdisintegration suggested that probably the presence of Ca2+ resulted in intra and/or inter cross-linked bridges in the CaCOG or CaCEG that supported water transporting system even when the aqueous channels in the FDTs were blocked. Thus, the findings indicated great potential for using CaCOG or CaCEG as superdisintegrants in FDTs with high mechanical strength and low DT.