Formation mechanism of wet-compressed rapidly disintegrating tablets containing a poorly water-soluble model drug

Rapidly disintegrating tablets are attracting attention as a dosage form that can be easily taken, even by elderly patients and children. In this study, rapidly disintegrating tablets were prepared by the wet-compression method and the formation mechanism of these tablets was evaluated. The tensile strength of the tablets increased with the amount of excipients (sugars) dissolved during the kneading process. More solid bridges were formed between drug particles and tablets with a greater tensile strength were obtained by increasing the amount of water and using more soluble sugars as excipients. When a swellable disintegrant was added, the porosity and the pore size of the tablets increased, probably because the disintegrant swelled by absorbing water during kneading, but shrank in the drying process after tableting. Thus, the use of a swellable disintegrant is considered to be important to induce the formation of a porous structure, which ensures rapid disintegration of the tablet. Therefore, optimization of the selection of the excipients (sugars) and disintegrant, and the amount of kneading water, was found to be necessary to prepare rapidly disintegrating tablets with a satisfactory tensile strength.