420 страниц. 2014 год. LAP Lambert Academic Publishing I am deeply thankful to GOD by the grace of whom the present work was realized. To my family, whose vision, enthusiasm, and unswerving support helped to make a lifelong dream come true. Several approaches are currently utilized in the prolongation of the gastric residence time, including floating drug delivery systems (FDDS), also known as hydrodynamically balanced systems (HBS). Therefore, the aim of this work was to formulate the metronidazole as it has an important role in the treatment of Helicobacter pylori infection of the stomach in different controlled release forms to prolong its duration of action using the floating technique to target the drug into its site of action. In addition, to maintain effective localized concentration of metronidazole and improve patient compliance.