A formulation containing the hydrochloride salt form of the non-imidazole histamine H2 receptor antagonist ranitidine, bismuth potassium citrate, and the hydrate form of sucralfate, a basic aluminum complex of sulfated sucrose, with potential antacid, radio- and cytoprotective activities. Upon oral administration of the ranitidine hydrochloride/bismuth potassium citrate/sucralfate hydrate formulation, ranitidine binds to and blocks the activity of the histamine H2 receptors in the parietal cells in the stomach and in the gastrointestinal (GI) tract, thereby decreasing acid secretion. Sucralfate physically binds to the surface of damaged mucosa, thereby forming a protective barrier that shields the GI tract from stomach acid. It also neutralizes stomach acid. Bismuth inhibits peptic activity, increases mucosal secretions and acts as a barrier to prevent damage by acid. Altogether, this protects against ulcer formation and may help to heal existing ulcers.