TARGETING OF DRUGS AND DELIVERY SYSTEMS TO SPECIFIC SITES IN THE GASTROINTESTINAL-TRACT

Particle uptake and translocation occur at specific sites in the gastr ointestinal tract. Several drugs are also absorbed from solution only through narrow 'windows' in the small intestine. In these circumstance s, optimum therapeutic benefit would be obtained if the active agent w as targeted to the appropriate site in the gastrointestinal tract. Tar geting relies on exploiting a unique feature of the intended site and protecting the active agent until it reaches that site, This minirevie w highlights the problems in achieving site specificity in the gastroi ntestinal tract and examines possible solutions to the problem for 2 r egions, the stomach and the colon.