The objectives of this study were (a) to evaluate the pharmacokinetics and to evaluate and compare the pharmacodynamics of ilaprazole and esomeprazole following a single dose (Day 1) and once daily (QD) administration for 5 consecutive days each of 10-mg, 20-mg, and 40-mg ilaprazole tablets and 40-mg esomeprazole tablets; (b) to evaluate the safety of 10-mg, 20-mg, and 40-mg ilaprazole tablets following QD oral administration for 5 consecutive days; and (c) to characterize the plasma gastrin concentration profile on Day 1 and Day 5 following QD oral administration of 10-mg, 20-mg, and 40-mg ilaprazole and 40-mg esomeprazole tablets for 5 consecutive days.

Inclusion Criteria:

• Prior to any study-specific procedures being performed, the subject voluntarily signed the approved informed consent/PIPEDA authorization form after having it fully explained and all questions answered.
• The subject was between 18 and 55 years, inclusive, and was generally in good health.
• Pregnancy test results for all females were negative in order to enter and remain in the study. A serum pregnancy test was performed on all females at Screening, Day -1 of each period, and Day 6 of Period 4 only, or if a subject prematurely discontinued. Results must have been negative in order for study drug to be administered.
• Female subject was using, and agreed to continue the use of, a double-barrier method of birth control. Oral, patch, implants, or injectable contraceptives were accepted as 1 method if the subject had been taking them for greater than 2 months at the Screening Visit. Subjects who had a bilateral tubal ligation, hysterectomy, or bilateral oophorectomy for a minimum of 6 months, or surgical sterilization of partner (vasectomy for 6 months minimum), or were postmenopausal (defined as the absence of menses for 2 years or the absence of menses for 12 months and follicle-stimulating hormone [FSH] level of >40 IU/L) did not require the use of birth control.
• Subject had a negative breath test result for H pylori prior to enrollment.
• At the Screening Visit, subject had a body mass index (BMI) within the range of 18 to 30 kg/m2, as determined by the following calculation.
• Subject was in general good health as evidenced by a medical history, a complete physical examination, and ECG without clinically significant abnormalities.

Exclusion Criteria:

• Subject had current evidence of cardiovascular, central nervous system, hepatic, hematopoietic, renal, or metabolic dysfunction; serious allergy, asthma, history of significant sensitivity to any drug; or lactose intolerance that would contraindicate taking ilaprazole or esomeprazole or would interfere with the conduct of the study.