Evaluation of pH Responsive Flipping Mechanism of 5-Fluorouracil Loaded LLC System for Colon Targeting

摘要: Lyotropic liquid crystals (LLC) capable of flipping their structure according to varying pH environment the GI tract were developed for colon-targeted delivery 5-fluorouracil (5-FU). A pH-sensitive LLC system loaded with 5-FU has been prepared by using different ratios monoolein (MO) and oleic acid (OA) facilitate drug targeting colon. The batches utilizing buffers, i.e., HCl buffer 1.2 (indicative gastric pH), acetate 4.5 duodenum fluid HEPES 6.8 small intestinal 7.4 (colon rectum pH). formulations confirmed crystal phase formed polarized light microscopy (PLM) characterized DSC, FESEM, content, rheology, texture analysis, in vitro release study vivo gamma-scintigraphic study. PLM occurrence both hexagonal cubic depending on ratio MO:OA used, which is further supported rheological determinations. insignificant 1.2, 4.5, up 5 h major colon 26 h showing more than 90% colonic region formulation containing 40% MO 60% OA. pattern from exhibits slow extended over longer periods time owing its ability remain less mucoadhesive at lower causing slower transforming into higher faster drug.