Oral ileocolonic drug delivery by the colopulse-system: A bioavailability study in healthy volunteers

The release profile of a novel oral ileocolonic drug delivery technology (ColoPulse-technology) was assessed by a combination of conventional kinetics of a marker substance in blood and site-specific signaling by stable isotope technology. Since ileocolonic delivery involves the drug release in a region in which bacteria are highly present, a prolonged lag time should coincide with proven bacterial enzyme activity. The latter can be tested using 13C-urea as the marker substance. The study was designed as a two period (uncoated versus coated capsule) crossover single dose bioavailability study in healthy subjects. The 13C-recovery data after oral administration of 13C-urea using the ColoPulse delivery system showed a delayed sigmoid release in all subjects with a lag time of > 3 h (median: 330 min.). Release was achieved in a urease-containing intestinal segment in all healthy subjects. Complete release in the ileocolonic region was achieved in 10 of 11 subjects. The ColoPulse-technology therefore enables specific and reliable drug delivery in the ileocolonic region in healthy volunteers. Recovery of 13C (as 13CO 2) in breath in combination with the lag time indicates that the coated capsule (ColoPulse-delivery system) delivered 13C (as 13C-urea) in urease-rich intestinal segments (ileocolonic region). [Display omitted]