 Eligible H. pylori negative, normal gastric acid secreting, healthy volunteers will be treated by the study medications in a randomized, open-label, cross-over study.Up to 60 volunteers may be enrolled to ensure that at least 30 subjects will complete all the study treatments. Omeprazole 20 mg will be administered before breakfast. Vecam 40300 and Vecam 20300 will be administered at bedtime wo food. 24-hour gastric pH will be measured after the fifth dose day 5.Following screening procedures, subjects will be randomly assigned to receive the different treatments. 