Drug delivery specifically in the colonic region is desired for treating Inflammatory Bowel Disease (IBD). Drug targeting to colon was done using chitosan coated liposomes; since liposomes accumulate in the inflamed tissue and chitosan proven mucoadhesive helps to improve the residence time in the tissue. Hence liposomes were prepared by film hydration method and formulation was optimised statistically by Box Behnken design. Optimised liposome dispersion was coated with chitosan, freeze dried and subjected to enzyme incubation and mucoadhesion study to find optimum chitosan coating level. The optimised chitosan coated liposomes were filled inside enteric coated capsules for release specifically in colon. Final formulation was tested on induced colonic inflammation in Wistar rats. Accumulation in inflammatory area was tested by Inverted sac method. Myeloperoxidase (MPO) activity and histopathology comparative study was carried out. The particle size of the resultant formulation was found to be 766 nm, with entrapment efficiency of 61.04%. The in-vitro studies of enteric coated capsules showed that drug release occurred after a lag time after 4 hours, which is approximately the time needed for the dosage form to reach the colon. Chitosan coating was confirmed by checking particle size and zeta potential. Ex-vivo studies indicated that drug accumulation in colonic tissue was greater for chitosan coated liposomes as compared to plain drug and non-coated liposomes. Histopathological examination of tissue showed considerable difference in extent of inflammation before and after treatment with liposomal drug as compared to pure drug.
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