The present investigation is aimed to formulate floating gastroretentive (GR) tablets containing diltiazem hydrochloride using a sublimation material.Three different grades of hydrophilic polymer Methocel® (hydroxypropyl methyl cellulose (HPMC)) K4M, K15M and K100M were used in different combinations at different ratios for the preparation of tablets. In this study, the release of the drug from tablet was highly dependent on the polymer concentrations. Camphor was used as the sublimation material to prepare GR tablets that are low-density and easily floatable.Camphor was changed to pores in the tablet during the sublimation process. SEM revealed that the GR tablets have a highly porous morphology. Floating properties of tablets and tablet density were affectedby the sublimation of camphor. Prepared floating gastroretentive tablets floated for over 24 h and had nofloating lag time. However, as the amount of camphor in the tablet matrix increased, the crushing strength of the tablet decreased after sublimation. Release profiles of the drug from the GR tablets were not affected by tablet density or porosity.
