The Effect of Oleic Acid on the Human Ileal Brake and Its Implications for Small Intestinal Transit of Tablet Formulations

Purpose. A human volunteer study was carried out to investigate whether activation of the ileal brake mechanism affects the transit of tablets through the small intestine.Methods. Oleic acid, which has previously been shown to activate the brake, was delivered to the small intestine in a modified release capsule at doses of 300 mg, 600 mg and 1200 mg. The effect of the oleic acid was determined by measuring the transit of two sets of radiolabelled tablets by gamma scintigraphy. One set of tablets was dosed with the capsule and the other one hour later.Results. The results show that in the majority of the volunteers small intestinal residence time was greater with the oleic acid than control. The effect was most pronounced in the tablets given concomitantly with the capsule and with the higher doses of oleic acid.Conclusions. The ileal brake, activated by oleic acid, can slow the transit of tablets through the small intestine.