Der Pharmacia Lettre
Abstract
Author(s): Shreeraj H. Shah, Jayvadan K. Patel, Nirav V. Patel
Floating multi-layer coated tablets were formulated based on gas formation. The system consists
of a drug containing core tablet coated with a protective layer (Hydroxy Propyl Methyl
Cellulose-HPMC), a gas forming layer (sodium bicarbonate) and a gas-entrapped membrane,
respectively. Eudragit RL 30D was chosen as a gas-entrapped membrane due high water
permeability and low CO2 permeability. The obtained tablets showed the buoyancy due to the
CO2 gas formation and the gas entrapment by polymeric membrane of Eudragit RL 30D. The
effect of formulation variables on floating properties and drug release was investigated. The
floating tablets using direct-compressed cores had shorter time to float and faster drug release
than those using wet-granulated cores. The increased ratio of sodium bicarbonate to HPMC
increased the drug release from the floating tablets while increasing coating level of gasentrapped
membrane increased floating lag time. Good floating properties and sustained drug
release were achieved. These floating tablets seem to be a promising floating gastroretentive
drug delivery system which can be targeted in stomach to eradicate H.pylori infection.
