Investigations on chitosan-carboxymethyl guar gum complexes interpolymer complexes for colon delivery of fluticasone

The present study was designed to formulate colon release tablets of fluticasone by employing cross linked chitosan (CH) and carboxymethyl guar gum (CMG) interpolymer complexes (IPC). Matrix tablets were prepared by wet granulation method using IPC as binder and coating agent. The IPC were characterized by Fourier transform infrared spectroscopy (FTIR). The uncoated and coated tablets were tested for their suitability as colon specific drug delivery system by in vitro dissolution studies. The coated tablets were evaluated for their pharmacodynamic performance after oral administration to TNBS induced ulcerative colitic rats. FTIR studies demonstrated that the IPC was formed through an electrostatic interaction between –COO groups of CMG and –NH3+ groups of CH. Tablets formulated with 50:50 CH:CMG as binder and coated with the respective ratio of IPC was capable of protecting the drug release in stomach and small intestine and delivering the drug in the colon. Histopathology of the rat colon after oral administration of these IPC film coated tablets revealed significantly greater (p<0.05) reduction in TNBS-induced ulcerative colitis The study confirmed that selective delivery of fluticasone to the colon can be achieved using cross-linked CH and CMG polysaccharides. Keywords: Chitosan; Colonic delivery; Carboxymethyl guar gum; Cross-linking; Guar gum; Fluticasone