metronidazole

Efficient Helicobacter pylori elimination requires delivery of the antibiotic locally in the stomach. High dose of metronidazole (250 to 750 mg) is difficult to incorporate in floating tablets but can simply be given in liquid dosage form.  By keeping the above observation in mind, we made an attempt to build up a new raft forming oral in situ gelling system of metronidazole with improved residence time using sodium alginate as gelling polymer to eliminate H. pylori.  Methods: oral in situ gelling formulations were prepared using sodium alginate, xanthan gum, calcium carbonate, and sodium bicarbonate. Prepared formulations were evaluated for density, viscosity, floating lag time, floating duration, swelling index and in vitro drug release. Results. All formulations (F1–F12) showed floating within 180 s and had floating duration  of more than 24 h. every formulations showed excellent pourability. It was observed that concentration of sodium alginate and xanthan gum had major influence on floating lag time, cumulative percentage drug release and other evaluation parameters. The batch F11 was optimized since it have good pourability with extended release of 10 hrs. Conclusion: oral in situ gelling system of metronidazole  can be formulated by  use of sodium alginate as a gelling polymer and xanthan gum as release retardant to control  the drug release for more than  10 hrs.

The aim of this study is to prepare gastroretentive dosage form based on the super porous hydrogel (SPH) composites using metronidazole as a model drug for eradication of H pylori.Blowing technique was used to prepare SPH composites. The latter was used as a body for the drug delivery system. The core was made from matrix granules. Four types of retardants (Beeswax, carnauba wax, ethylcellulose, and Eudragit®RS) were used to prepare the granules by fusion for waxes and wet granulation methods for other polymers. For each retardants, two ratios (1:1 and 1:0.5 of drug: retardant) were used. Simple new method for insertion of core inside the SPH composite by using syringe with wide end opening without use of glue to close the insertion site was applied. The system was characterized by scanning electron microscopy, FT-IR. Also swelling, mechanical, and dissolution properties were studied. Scanning electron microscopic images clearly show highly porous structure and interconnected channels. FT-IR study confirmed the formation of crosslinking poly (acrylamide- sulfopropyl acrylate) SPH composites. The delivery system achieved the equilibrium swelling in about 3 minutes with swelling ratio of 10.45 ± 0.9 and penetration pressure of 483.34 ± 48.0 cm H2O. The results showed non-significant (p > 0.05) difference between loaded and unloaded SPH composites regarding mechanical and swelling properties. A significant difference (P < 0.05) was found among the cumulative amount of metronidazole released with time depending on the nature and ratio of each retardant. It can be concluded that the proposed drug delivery system based on superporous hydrogel composite is promising for gastroretentive stomach specific delivery of metronidazole. Key words: Superporous hydrogel composites, Gastroretentive dosage form, metronidazole