Evaluation of a gastro-resistant pulsed release delivery system (Pulsincap) in humans

Using gamma scintigraphy, the behavior of a colon-targeted drug delivery system was followed in nine volunteers to ascertain the time and position in the gastrointestinal tract of a Pulsincap(TM) device when enteric coat dissolution and plug release occurred. Each subject received a single radiolabeled unit with either 50 mL (study 1) or 150 mL water (study 2) after fasting overnight. Anterior, posterior, and lateral views were recorded for up to 12 h after dosing and the images stored for analysis. Dissolution of the enteric coat was observed between 29 and 70 min after gastric emptying with release of the indium label in the small intestine. In the second study, separation of the body and plug of each device was evident in all six subjects after a mean time of 5.34 +/- 1.03 h (4.90 +/- 1.07 h after gastric emptying). In all eases, plug release occurred in the cecum or ascending colon. In one subject, visualization of separation of plug and body was delayed; at more than 10 h into the study separation was not evident; thereafter, at 10.5 h the separation was 5 cm. The data suggest that the device has excellent potential for positioned delivery of drugs into the gastrointestinal tract.