Novel raft forming systems incorporating curcumin-Eudragit 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 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 EPO was used to incorporate into the raft forming
systems. The raft forming formulations were composed of curcumin-Eudragit 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.