Abstract
The aim of the present work was to develop colon specific drug delivery system for ibuprofen using natural polymers as carriers. We have investigated colon specific, pulsatile device to achieve time and site specific release of ibuprofen based on chronopharmaceutical considerations. The basic design consists of an insoluble hard gelatin capsule body, filled with ibuprofen surface solid dispersions and sealed with guar gum hydrogel plug. The entire capsule was coated with ethyl cellulose, so that the variability in gastric emptying time can be overcome and a colon specific release can be achieved. Surface solid dispersions (SSDs) of ibuprofen were prepared using natural polymers such as Guar gum (GG), Hupu gum (HG) and Xanthan gum (XG) in the weight ratios of 1:0.5, 1:1 and 1:2 by using solvent evaporation method. Physicochemical properties of the prepared SSD were characterized by FTIR and DSC. Optimized SSD were obtained by practical yield, drug content, solubility and dissolution studies and were selected for further fabrication of pulsincaps. Guar gum was used as hydrogel plug material to maintain a suitable lag period. The prepared pulsincaps were evaluated for in-vitro release. Pulsincap formulated with Ibuprofen-Hupu gum (PF3) at 1:2 ratio of surface solid dispersions showed highest drug release over the period of 12 hr and release was found to be Higuchi model kinetics. The present research study results have confirmed that the modified pulsincap of ibuprofen is a suitable device for the time dependent and site specific delivery to the colon segment of GIT.
Keywords: Surface solid dispersions, chronotheraphy, hydrogel plug, guar gum, hupu gum, pulsincap.