ABSTRACT
If the lumen of the small intestine is occluded by inflating a balloon a short distance below the pyloric sphincter, the plasma levels of glucose from a glucose drink are reduced when compared to levels obtained with free transit of the liquid36. Experiments of this type allowed an estimate to be made of the length of intestine required to absorb a particular material. Many nutrients are absorbed almost completely by the time the meal reaches a point 100 cm from the pylorus73. This formed the basis of the hypothesis that absorption of the drug from a particular formulation was completed in the upper part of the small intestine, and the remaining length was a “reserve”, i.e. unused for drug absorption74. If the reserve length was long, this implied that the drug was rapidly absorbed.
