1. Healthy males aged from 18 to 45 years

2. Have a body weight over 50kg, have a body mass index (BMI) 19-25 kg/m^2 (both inclusive)

3. Alanine aminotransferase<50 U/L, aspartate aminotransferase<50 U/L, alkaline phosphatase and total bilirubin <1.5x the upper limit of normal

4. According to Cockcroft-Gault, estimated Clcr≥90ml/min

5. Able to comprehend and willing to sign the informed consent form

1. Hepatitis B surface antigen(+)， Hepatitis C virus antibody(+)，AIDS antibody（+）

2. History of syncope, palpitations, bradycardia and tachycardia (for example any degree of atrioventricular block, left bundle branch block, right bundle branch block), or have an abnormal result of overall physical examination (vital signs, physical examination), routine laboratory assessment (hematology, biochemistry and urinalysis), 12-lead ECG and abdominal sonography (liver, gallbladder, pancreas, spleen, kidney)

3. Have had an alcohol and substance abuse within 6 months of screening

4. History of smoking within 3 months of screening

5. BP>140/90 millimetres of mercury, or heart rate >100 bpm

6. QT interval >450ms

7. History of drug-induced allergy or of hypersensitivity for digoxin and PEX168

8. History of serious heart disease or lung disease

9. Fasting triglyceride>1.5x the upper limit of normal

10. Subjects with liver disease or have history of liver disease or abnormal liver and gallbladder conditions

11. Donation of blood in excess of 400 mL within the 3 months of screening; or donation of blood within 1 month of screening; or received blood transfusions within 1 month of screening.

12. Hypothyroidism

13. Surgery of gastrointestinal tract

14. History of pancreatitis

15. History of cholecystitis or other gallbladder disease

16. History of inflammatory bowel disease or irritable bowel syndrome

17. History of MEN type 2 syndrome

18. History of medullary thyroid carcinoma

19. A family history of MEN type 2 syndrome and medullary thyroid carcinoma

20. Have participated in clinical trials with drug or medical devices involved within 3 months of screening

21. Have received any drug that may affect the study drugs within 2 weeks of screening, including prescribed drugs, over-counted drugs, Chinese traditional medicine or multivitamins

22. History of grapefruit juice, cranberry, mango, foods and drinks of xanthine or caffeine, strenuous exercise, or any other factor affect the absorption, distribution, metabolism and excretion of the study drug within 2 days of screening

23. Have received any glucagon-like peptide-1 mimetic compound(e.g., exenatide)

24. Have been disagreed to use a reliable method of birth control during the study and for 6 months following the last dose of study drug

25. History of any other condition, which in the opinion of the investigator, may prevent the subject from following and completing the protocol