We have developed a technique for specific drug targeting to digestive tract regions using electrostatic polysaccharide characteristics to cause gelation. An in situ double cross-linking process, mediated by Ca2+ and SO42-, of chitosan and alginate administered to the mouse gastrointestinal tract by double gavage, was used for gel formation. The technique not only allows researchers to target drug to different regions of the gastrointestinal (GI) tract by modulating polymer concentration but also significantly reduces degradation of the drug as well as side effects. Using this new technique, lower doses of drug can be efficiently loaded and delivered at specific target areas of the GI tract.