A Study to Evaluate the Safety, Tolerability and Pharmacokinetics/Pharmacodynamics of Oral Doses of H008

Inclusion Criteria: 1. Adult, male and female volunteers, 18 to 55 years of age, inclusive, at the time of dosing. 2. Ability to understand and willingness to sign a written informed consent form (the consent form must be signed by the subject prior to any study-specific procedures). 3. Willingness and ability to comply with study procedures and follow-up examination. 4. Body mass index (BMI) ≥18 to ≤30 kg/m2 and total body weight ≥50.0 kg for males and ≥45.0 kg for females at screening. * If female and of childbearing potential (premenopausal and not surgically sterile), the subject:Must have a negative serum pregnancy test at screening. The serum pregnancy test must be obtained prior to the first administration of H-008 (≤72 hours prior to dosing) in all women. * Must agree to use an acceptable method of effective contraception for the duration of the study and for 3 months after receiving the last dose of study treatment. If male, the subject agrees to: * Use an acceptable method of effective contraception (a dual method of contraception: condom with spermicide in conjunction with use of an intrauterine device (IUD), condom with spermicide in conjunction with use of a diaphragm, condom with birth control patch or vaginal ring, or condom with oral, injectable, or implanted contraceptive) for the duration of the study and for 3 months after receiving study treatment. * Abstain from sperm donation for the duration of the study and for 90 days after receiving the last dose of study treatment. * Ensure their partner not get pregnant until 3 months following administration of the last dose of study treatment. * Be vasectomized for at least 6 months or take appropriate precautions to avoid fathering a child. * Male subjects who do not have sexual partners, they need to agree to remain abstinent at the time of screening, or agree to use a double barrier if they become sexually active. Use of hormonal contraceptive methods will not be allowed. 5. Medically healthy on the basis of medical history, and physical examination (including but not limited to an evaluation of the cardiovascular, gastrointestinal, respiratory and central nervous systems), as determined by the Investigator at Screening and each Check-In visit. 6. Medically healthy based on the absence of clinically significant abnormal vital sign measurements, clinical laboratory test results (especially tests for renal and hepatic function) as determined by the Investigator at Screening and Check-In visit. 7. Medically healthy based on the absence of clinically significant abnormal vital sign measurements, clinical laboratory test results (especially tests for renal and hepatic function) as determined by the Investigator at Screening and each Check-In visit. 8. Non-smokers (including nicotine-containing products) for at least 3 continuous months prior to the first dose. Exclusion Criteria: A subject is not eligible for the study if any of the following criteria is met: 1. Subjects who have a history of drug allergy or atopic allergic disease (e.g. asthma, urticaria, eczema, dermatitis, etc.) that were clinically significant, or allergic to any known ingredients and excipients of H008 and other PPIs drugs (e.g., Omeprazole, Lansoprazole, Ilaprazole, Esomeprazole, Rabeprazole, etc.). 2. History of alcohol or drug/substance abuse (within 2 years). 3. Positive urine drug screen or alcohol breath test at screening or baseline (Day -2). 4. Subjects who have history of unexplained syncope or fainting or a condition that predisposes them to syncope, such as hypotension, orthostatic hypotension, bradycardia or dehydration. 5. Subjects determined by the Investigator to have any medical condition that could jeopardize their health or prejudice study results (e.g., history of surgery of the gastrointestinal tract, which may interfere with absorption, except for appendectomy and cholecystectomy). 6. Subjects who have used P-gp and/or CYP 450 hepatic microsomal enzyme-inducing or inhibiting drugs (e.g., propafenone, voriconazole, fluconazole, cimetidine) within 30 days of first dosing. 7. Subjects with history or presence of significant cardiovascular, pulmonary, hepatic, gallbladder or biliary tract, renal, hematologic, gastrointestinal, endocrine, immunologic, dermatologic, neurologic, psychiatric disease, or active sexually transmitted disease. 8. History or clinical evidence of achlorhydria, severe gastrointestinal disease, particularly diarrhea or other conditions affecting gastrointestinal mobility or absorption. 9. Subjects who have difficulty in swallowing oral tablets or capsules. 10. History or presence of significant cardiovascular abnormalities, including without limitation, severe bradycardia, sick sinus syndrome, second- or third-degree atrial ventricular block, long QT syndrome, cardiogenic shock, and decompensated heart failure. 11. History or presence of pro-arrhythmic conditions, including a marked baseline prolongation of QTcF interval (i.e., repeated demonstration of a QTcF interval \>450 milliseconds for males and \>470 milliseconds for females) or a history of additional significant risk factors for torsade de pointes (e.g., family history of long QT syndrome), including any evidence of QTcF prolongation at screening; 12. Subjects who test positive at screening for human immunodeficiency virus (HIV), Hepatitis B surface antigen (HBsAg), or Hepatitis C virus (HCV) antibody. 13. Subject is unable to refrain from or anticipated the use of any medication, including prescription and non-prescription drugs or herbal remedies (such as St. John's Wort \[hypericum perforatum\]), or grapefruits, grapefruit juice, blood oranges, apples and mulberry juice as well as vegetables from the mustard green family (e.g., kale, broccoli, watercress, collard greens, kohlrabi, Brussels sprouts, and mustard greens) beginning approximately 2 weeks prior to administration of the initial dose of investigational product, throughout the study, until the poststudy visit. Use of hormonal contraceptive methods will not be allowed. 14. Subjects donated blood (excluding plasma donation) of approximately 500 mL within 56 days prior to first dosing or donated plasma within 7 days prior to first dosing. Subjects will be advised not to donate plasma for 14 days after completing the study. 15. Subject consumes excessive amounts of caffeine for one month prior to investigational product administration, defined as greater than 6 servings (1 serving is approximately equivalent to 120 mg of caffeine) of coffee, tea, cola, or other caffeinated beverages per day. 16. Subjects who have participated in any other clinical trial within 30 days prior to the screening or five half lives of the investigational product received in the other trial. 17. Females who are pregnant, lactating, or likely to become pregnant during the study. 18. Abnormal gastric pH rhythms over 12 hours on Day -1, including abnormal pH increase lasting for more than 1 hour during non-eating or supine period, as judged by the physician. 19. Other conditions that an Investigator believes are not suitable for participation in the study.