Pharmacodynamic Study Comparing the Effects of Two Different Forms of Omeprazole (P07812) (COMPLETED)

This randomized, crossover study is to evaluate the early effectiveness, defined as effect on intragastric pH during the first 4 hours after dosing, of Zegerid, Prilosec over-the-counter (OTC) Tablets, and placebo on the 4th day of treatment to inhibit acid secretion. Additional purposes are to: 1. provide pharmacodynamic evidence comparing 24-hr inhibition of acid secretion on the 1st, 4th, and 11th days of dosing with each of the indicated treatments; 2. compare Zegerid and Prilosec OTC for achieving their steady-state effects for controlling 24-hr gastric acidity at steady-state on the 4th and 11th day of dosing. 3. evaluate early effectiveness, defined as effect on intragastric pH during the first 4 hours after administration, of Zegerid, Prilosec OTC Tablets, and placebo on acid inhibition at steady-state when administered on the 11th day of dosing.