title: Guar gum as potential film coating material for colon-specific delivery of fluorouracil.
abstract: The potential of guar gum as a film coating material for colon-specific delivery of 5-fluorouracil is evaluated in this study. The guar gum-based multi-unit pellet system is prepared by coating guar gum and pH-sensitive polymer Eudragit FS30D sequentially around drug-loaded non-pareil cores in a fluid-bed coater. The outer Eudragit FS coating protects the system against gastrointestinal environment and dissolves rapidly in distal small intestine, where a lumen pH of over 7 triggers the dissolution of the enteric polymer. The inner guar gum coating works as a time-controlled retardant and offers additional protection of the pellets until it is degraded by microbial enzymes at the proximal colon. In vitro results indicate that guar gum is a feasible coating material to achieve timed and enzyme-triggered fluorouracil release. Pharmacokinetic study in beagle dogs shows delayed absorption of about 5 h and limited absorption fraction as a result of guar gum and Eudragit FS coating.
authors.affiliation: School of Pharmacy, Fudan University, Shanghai 200032, China.
authors.forename: C M
authors.initials: CM
authors.lastname: Ji
authors.forename: H N
authors.initials: HN
authors.lastname: Xu
authors.forename: W
authors.initials: W
authors.lastname: Wu
mesh_terms: D000818:Animals; D002432:Cecum / Q000201:enzymology / Q000382:microbiology; D020099:Coated Materials, Biocompatible / Q000737:chemistry; D003106:Colon / Q000187:drug effects* / Q000378:metabolism; D004285:Dogs; D016503:Drug Delivery Systems; D005472:Fluorouracil / Q000008:administration & dosage* / Q000097:blood / Q000493:pharmacokinetics; D005685:Galactans / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D007408:Intestinal Absorption; D007700:Kinetics; D008351:Mannans / Q000737:chemistry; D008361:Mannosidases / Q000378:metabolism; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D053149:Plant Gums / Q000737:chemistry; D011109:Polymethacrylic Acids; D013608:Tablets, Enteric-Coated / Q000737:chemistry
chemical_list: D020099:Coated Materials, Biocompatible; D005685:Galactans; D008351:Mannans; D053149:Plant Gums; D011109:Polymethacrylic Acids; D013608:Tablets, Enteric-Coated; C038300:methylmethacrylate-methacrylic acid copolymer; C007894:guar gum; D008361:Mannosidases; C109435:galactomannanase; D005472:Fluorouracil