Selective drug delivery to the colon using pectin : chitosan : hydroxypropyl methylcellulose film coated tablets

A study has been carried out to assess the potential of pectin:chilosan:hyd roxypropyl methylcellulose (HPMC) (P:C:H) films for colonic drug delivery. Radiolabelled (Tc-99m) tablets were coated with a 3.1:1, P:C:H film and adm inistered to human volunteers. The gastro-intestinal transit of the tablets was assessed by gamma scintigraphy. The results showed that in all cases ( n = 4), the tablets were able to pass through the stomach and small intesti ne intact. Break up of the tablets commenced once they were in the colon, d ue to degradation of the coat by colonic bacteria. The study has highlighte d the potential of this coating system for colonic drug delivery. (C) 1999 Elsevier Science B.V. All rights reserved.