From Day 2 ~ 6, subjects were dosed Losec 40 mg or CDFR0209 around 8 AM. On Day 7, subjects was dosed Losec 40 mg or CDFR0209 (Omeprazole 40 mg & sodium bicarbonate 1,100 mg) around 8 AM and ambulatory intragastric pH recording was performed upto 24 hours after dosing.