Feasibility study on the retention of superporous hydrogel composite polymer in the intestinal tract of man using scintigraphy

In recent years, many complex oral drug delivery systems have been developed using various polymers in order to achieve better drug targeting and drug absorption in the intestinal tract. Superporous hydrogel (SPH) and SPH composite (SPHC)-based drug delivery systems were also developed for the targeted delivery of peptide drugs into the intestinal tract. In the present study, the retention time of SPHC polymer is studied in man using the scintigraphy technique. To that purpose, SPHC polymers were radiolabelled with Tc-99m and administered orally in an enteric-coated gelatin capsule. The location of the radiolabelled polymer was monitored in five healthy volunteers while the subjects were sitting in front of a large field of view gamma camera. The results showed that enteric-coated gelatin capsules remained in the stomach for 75 to 150 min after oral administration to fasted volunteers and that the SPHC polymers thereafter attached to the upper part of the small intestine for at least 45 to 60 min due to their mechanical fixation properties. No discomfort was observed in any of the volunteers after oral administration of these polymers, which indicates that they are safe to be applied for oral drug delivery systems in man. (C) 2004 Elsevier B.V. All rights reserved.