Tetracycline-containing Chitosan Microspheres for Local Treatment of <Emphasis Type="Italic">Helicobacter pylori</Emphasis> Infection

Helicobacter pylori infection is currently known to be the cause of at least 75% of all peptic ulcers. Although triple therapy protocols used at present in the clinics have resulted in significant benefits to the patients, the ultimate 100% eradication efficiency has never been achieved. In addition, the development of multidrug resistance to standard anti-microbial therapy can seriously hinder effective management of the disease. A rational approach to treat H. pylori, which localizes predominantly in the antral region of the stomach, is necessary for complete eradication of the infection. In this article, I review the summary of our work over the last several years on development of stomach-specific anti-H. pylori therapy using bioadhesive chitosan microspheres. To determine the gastric residence and local tetracycline concentrations as a function of time, tetracycline-containing chitosan microspheres were formulated and evaluated using the fasted Mongolian gerbil model. The H. pylori-infected gerbil model was used to evaluate the efficacy of the tetracycline-containing chitosan microsphere formulation. These preliminary results show great promise for this delivery strategy in the treatment of localized gastro-intestinal tract infections. Drug carrier systems can be engineered with the appropriate therapeutic agent(s) for efficient delivery to the target site and provide better control over localized infectious diseases. This strategy will ultimately lead to favorable clinical outcomes with less potential for resistance development.