Pharmacokinetic and Safety of Dexlansoprazole in Adolescents With Gastroesophageal Reflux Disease

Inclusion Criteria: * Body weight is greater than or equal to 30 kg. * Females of childbearing potential who are sexually active must agree to use an acceptable form of contraception, and can neither be pregnant nor lactating from Screening throughout the duration of the study. * Must have an estimated creatinine clearance greater than or equal to 80 mL/minute as determined from the Cockcroft-Gault formula. * Participants who take prescription or non-prescription proton pump inhibitors, histamine receptor antagonists (except cimetidine), sucralfate, or antacids on a regular or as required basis must agree to discontinue usage throughout the study. * Must have a history of gastroesophageal reflux disease symptoms, as documented by a physician, for at least 2 months prior to Screening or is currently symptomatic. * Must be able to swallow study drug capsule or must be able to ingest study drug granules sprinkled on 1 tablespoon of applesauce. Exclusion Criteria: * Has evidence of current cardiovascular, central nervous system, hepatic, hematopoietic, renal, or metabolic dysfunction, serious allergy, asthma, or allergic skin rash. * Has any finding in his/her medical history, physical examination, or safety clinical laboratory tests giving reasonable suspicion of a disease that might interfere with the conduct of the trial or that would contraindicate taking dexlansoprazole MR or a similar drug in the same class. * Has a known hypersensitivity to any proton pump inhibitors or any component of the formulation of dexlansoprazole MR (see most current version of the Investigator Brochures). * Has a history of malignant disease. * Has a positive test result for hepatitis B surface antigen, hepatitis C virus antibody. * Has a known history of infection with the human immunodeficiency virus. * Has donated or lost greater than or equal to 300 mL blood volume, undergone plasmapheresis, or has had a transfusion of any blood product within 90 days prior to the first dose of study drug. * Is required to take or intends to continue taking any disallowed medication, prescription medication, herbal treatment or over-the counter medication that may interfere with evaluation of the study medication. * Has consumed grapefruit or grapefruit juice within 14 days prior to the first dose of study drug or is unwilling to agree to abstain from grapefruit or grapefruit juice while participating in the study. * Has a history of alcohol abuse or illegal drug use or drug abuse in the past, or tests positive for alcohol or drugs of abuse at the initial Screening Visit or Day -1 or is unwilling to agree to abstain from alcohol and drugs throughout the study. * Has used a product containing nicotine within 90 days prior to the first dose of study drug or has a positive cotinine screen at the initial Screening Visit or Day -1 or is unwilling to agree to abstain throughout the study. * Has participated in a study of an investigational agent (including dosing or follow up) within 30 days prior to first dose of study drug. * Has an initial Screening Visit or Day -1 laboratory value that the principal investigator considers to be clinically significant. * Participant is determined to be a CYP2C19 isozyme poor metabolizer (ie, genotyped homozygous non-wild type). * Is unlikely to comply with the protocol or is unsuitable for any other reason per the opinion of the investigator