Gastroretentive floating tablets: An investigation of excipients effect on tablet properties

Present communication was aimed to investigate the effect of excipients on buoyancy and drug release properties from the floating tablets. Gastroretentive floating tablets were developed by the wet granulation method using hydroxypropyl methylcellulose (HPMC K4M), carbopol 934P and carbopol 971P as a rate controlling polymers and crospovidone as a dissolution enhancer. Sodium bicarbonate and citric acid were used as a gas generating agent. PVP K30 was used as granulating agent. The effect of formulation variables on tablet performance was examined quantitatively based on buoyancy properties, swelling behavior and drug release profiles. The drug release mechanism was investigated using mathematical models. It was found that HPMC/carbopol matrices at 1: 1 ratio with crospovidone and sodium bicarbonate gave sustained and better drug release profile upto 24 h when compared to HPMC or carbopol matrices alone. The mechanism of drug release was found to be anomalous non Fickian.