Fabrication and optimization of fast disintegrating tablets employing interpolymeric chitosan-alginate complex and chitin as novel superdisintegrants.

The objective of the present work was to optimize the formulation of fast disintegrating tablets (FDTs) of ondansetron HCl containing novel superdisintegrants, possessing sufficient mechanical strength and disintegration time comparable to those containing crospovidone or croscarmellose sodium. The FDTs were formulated using a novel superdisintegrant (chitosan-alginate (1:1) interpolymer complex and chitin) to achieve a sweet tasting disintegrating system. The results revealed that chitin (5-20%) increased the porosity and decreased the DT of tablets. At higher concentrations chitin maintained tablet porosity even at 5.5 kg crushing strength. Ondansetron HCl was found to antagonize the wicking action of glycine. Further, evaluation of the mechanism of disintegration revealed that glycine transported the aqueous medium to different parts of the tablets while the chitosan-alginate complex swelled up due to transfer of moisture from glycine. This phenomenon resulted in breakage of the tablet within seconds. For preparing optimized FDTs, the reduced model equations generated from Box-Behnken design (BBD) were solved after substituting the known disintegration time of FDTs containing superdisintegrants in the reduced model equations. The results suggested that excipient system under investigation not only improved the disintegration time but also made it possible to prepare FDTs with higher crushing strength as compared to tablets containing known superdisintegrants.