Stomach-site specific drug delivery system of clarithromycin for eradication of Helicobacter pylori.

Gellan gum based floating beads containing clarithromycin (FBC) were prepared by iontotropic gelation method for stomach-specific drug delivery against Helicobacter pylori. The scanning electron microscope photograph indicated that prepared beads were spherical in shape with rough outer surface. Formulation variables such as concentrations of gellan, calcium carbonate and drug loading influenced the in vitro drug release characteristics of prepared beads. In vitro release rate of clarithromycin was corrected using first order degradation rate constant which is degraded significantly during the release study in simulated gastric fluid pH 2.0. Further, the absence of interactions between drug and polymer was confirmed by differential scanning calorimetry analysis. Kinetic treatment of the in vitro drug release data with different kinetic equations revealed matrix diffusion mechanism. Prepared beads showed good anti-microbial activity against isolated H. pylori strain. The prepared beads have shown good in vivo floating efficiency in rabbit stomach. The stability studies of beads did not show any significant changes after storage of beads at 40 degrees C/75% relative humidity for 6 months. The preliminary results from this study suggest that floating beads of gellan can be used to incorporate antibiotics like clarithromycin and may be effective when administered locally in the stomach against H. pylori.