Natural Polysaccharides: An Overview of their Role in the Development of Microparticles for Stomach Targeting

Abstract

Drugs, having shorter half-life, 10 low oral bio availability, 11 low water solubility, 12 dosing several times a day, undesirable fluctuations in gastric fluids, 13 active locally in the stomach, narrow absorption window in GIT, unstable in the intestinal or colonic environment, disturb normal colonic microbes, exhibit low solubility at high pH values 14 are suitable candidates for formulation of gastro retentive microparticles. NATURAL POLYSACCHARIDES USED FOR THE PREPARATION OF MICROPARTICLES The drug release and better-floating properties of microparticles mainly depend on the type of polymer, surfactant and solvent used in the preparation. 15 Various types of natural polymers have been reported for their role in formulation of stomach specific floating microparticles. Commonly used natural polymers are polysaccharides (Table 1). More than 90% of the carbohydrate mass in nature is in the form of polysaccharides. These are polymers of monosaccharides with high molecular weight. Polysaccharides are gel-forming agents as well as hydrocolloids (Table 1), when come in contact with gastric fluids form gel and they