Clinical Trial to Assess the Efficacy and Safety of YYD601 in NERD Patients

Inclusion Criteria: * A man or woman over 20 years old less than 70 years old. * A man or woman who has below all characters and diagnosis as NERD. 1. A man or woman who has experienced symptom(hearburn or/and acid regurgitation) over 3month at least. 2. A man or woman who has experienced symptom(heartburn or/and acid regurgitation) within 7days before Visit1, meet below 1) or 2) criteria. \*\* Symptom (heartburn and acid regurgitation) is confirmed by RDQ * Experienced above 2 days in a week, heartburn of acid regurgitation above the weakness. * Experienced above 1 day in a week, heartburn of acid regurgitation above the middle. 3. A man or woman who has been made diagnosis as LA grade0(Zero) measured through the dendoscopy which is corried out within 14 days, there is no observed muscosal break. * A man or woman who has a full understanding of this clinical trial through the detailed explanation, agree in writing to participate in this trial. Exclusion Criteria: * Who has hyper sensitivity reaction about other drugs, ingredients, components of investigator product or compound of benzimidazole. * Who has ERD. * Who get a diagnosis as a IBS within the last 3 months. * Who have taken drugs about reflux esophagitis (H₂-receptor inhibitor (H2RA) Prostaglandin(PG), Antacid, Prokinetic acid etc.) above 2 times as an usual dose. (\* refer to the Concomitant medication in text.) * Who havbe taken gastric acid secretion inhibitors including PPIs within 2 weeks before the endoscopy. * Who has been experienced the disease affecting the esophagus(Eosinophilic esophagitis, esophageal varices, cirrhosis, Virus or Fungal infection, Esophageal stricture, primary esophageal motility disorder and gastrointestinal bleeding). Or who has a history of radio therapeutics, freeze treatment about the esophagus. * Who has the gastric or duodenal ulcer, Zollinger-Ellison and other acid hypersecretory condition been experienced. * Who has hyper-sensitivity, reaction about PPIs (ex. Lansoprazole, omeprazole, rabeprazole, pantoprazole or esomeprazole). * Who has gotten a diagnosis as a cancer within 5 years before participated in this clinical trail (expect the basal cell on the skin), peptic ulcer or benign tumor.