17-04-2012, 11:12 PM
ABSTRACT
Present study was designed to minimize the drug release in upper gastro intestinal tract and
target to colon by using the principles of compression coat. Compression coated tablets are
prepared by direct compression method using guar gum alone (or) combination of
guargum/metalose 90 SH polymers. Tablets are evaluated for their physicochemical properties
and in vitro drug release studies. All the properties of core and coat formulations are with in
house specifications. In vitro drug release studies are performed without rat caecal contents (as
a control) and with rat caecal contents. In the rat caecal contents formulations shows enhanced
drug release due to degradation of guar gum coat by colonic galactomannanase enzyme. Coat
thickness and amount of guargum/metalose 90 SH parameters controls the release rate.
Compared to individual guar gum combination of guar gum with metalosee 90 SH (F9) provides
minimize the drug release in upper GIT and maximizing the release of drug in colon. All the
formulations ar best fitted with zero order kinetics and mechanism of drug release was non-
Fickian (super case -II). FTIR studies reveals there is no drug-excipient interaction. Optimized
F9 formulation was a promising system targeting to colon for treatment of various colonic
diseases like Inflammatory Bowel disease (IBD).