Colon-specific delivery and enhanced colonic absorption of [Asu(1,7)]-eel calcitonin using chitosan capsules containing various additives in rats.

The objective of this study was to estimate the colon-specific delivery of [Asu1,7]-eel calcitonin (ECT) using chitosan capsules in rats. The intestinal absorption of ECT was evaluated by measuring the plasma calcium levels after oral administration of the chitosan capsules containing ECT and different combinations of additives. The same combinations were investigated by an in situ absorption experiment prior to in vivo administration of capsules.