Acta Pharm. 51 (2001) 21-33
Floating tablets offer a new possibility of treating the stomach infected with Helicobacter pylori. The objective of this study was to select suitable materials for the formulation of floating tablets with sustained drug release properties. In the preformulation studies the differences between cellulose polymer (HEC, HPC, HPMC K4M, Avicel) isotherms were estimated using the DVS method and the disappearance of gas-generating agent at higher relative humidities was observed. The correlation between wettability and the floating lag time proves that the first contact with water is not essential for good floating. Tablets with an incorporated drug stored at high relative humidity have a lower crushing force, the floating lag time increased, but the release profile did not change. Optimally designed tablets with ciprofloxacin hydrochloride monohydrate have good resistance to crushing, a floating lag time of less than 1 minute, float longer than 24 hours. The fact that they enable a more than 8-hour-long controlled drug release from non-disintegrated matrices plays an important role in prolonging gastric residence time.
Keywords: floating tablet, cellulose ethers, adsorption isotherm, contact angle, release, ciprofloxacin