Mucoadhesive systems are those which bind to gastric epithelial cell surface or mucin and serve as a potential means of extending GRT of drug delivery system in the stomach by increasing the duration of contact of drug with the biological membrane. Mucoadhesive microspheres include microparticles and microcapsules (having a core of the drug) of 1-1000nm in diameter and consisting either entirely of a mucoadhesive polymer or having an outer coating of it,respectively.All duodenal ulcers and most gastric ulcers caused by H.Pylori acid inhibition with antibiotic treatment is highly effective in eradication of H. Pylori. Approximately 85-100% of all duodenal ulcers, 70-90% of all gastric ulcers are associated with H.Pylori infection in the stomach.The combination of antibiotics ie dual therapy or triple therapy is preferred for treatment of H.Pylori infection .It is proved that Clarithromycin and Omeprazole resided in the stomach for a longer period of time.,when they are administered in the form of Mucoadhesive nanoparticles than when administered as uspension. The plugging and sealing effect of Mucoadhesive nanoparticles could also impart superior targetability and protect the drug