Development and evaluation of gastroretentive raft forming systems incorporating curcumin-Eudragit (R) EPO solid dispersions for gastric ulcer treatment

摘要

Novel raft forming systems incorporating curcumin-Eudragit (R) EPO solid dispersions were developed to prolong the gastric residence time and provide for a controlled release therapy of curcumin to treat gastric ulcers. The solid dispersions of curcumin with Eudragit (R) EPO were prepared by the solvent evaporation method at various ratios to improve the solubility and the dissolution of curcumin. The optimum weight ratio of 1:5 for curcumin to Eudragit (R) EPO was used to incorporate into the raft forming systems. The raft forming formulations were composed of curcumin-Eudragit (R) EPO solid dispersions, sodium alginate as a gelling polymer and calcium carbonate for generating divalent Ca2+ ions and carbon dioxide to form a floating raft. All formulations formed a gelled raft in 1 min and sustained buoyancy on the 0.1 N hydrochloric acid (pH 1.2) surface with a 60-85% release of curcumin within 8 h. The curative effect on the acetic acid-induced chronic gastric ulcer in rats was determined. The curcumin raft forming formulations at 40 mg/kg once daily showed a superior curative effect on the gastric ulcer in terms of the ulcer index and healing index than the standard antisecretory agent: lansoprazole (1 mg/kg, twice daily) and a curcumin suspension (40 mg/kg, twice daily). These studies demonstrated that the new raft forming systems containing curcumin solid dispersions are promising carriers for a stomach-specific delivery of poorly soluble lipophilic compounds. (C) 2015 Elsevier B.V. All rights reserved.