The purpose of the study is to investigate the potential interaction between multiple oral doses of SHR3824 and a single oral dose of metformin in healthy adult volunteers.

This is an open-label (volunteers will know the names of treatments they are assigned) single-center study of SHR3824 and metformin in healthy adult volunteers. SHR3824(a Sodium-Glucose Cotransporter 2 inhibitor) is currently under development to lower blood sugar levels in patients with type 2 diabetes mellitus (T2DM) and metformin is an approved treatment for patients with T2DM. SHR3824 will be administered orally (by mouth) as 25 mg on Days 4, 5, 6, 7, and 8 and metformin will be administered orally as two 500mg tablets on Days 1 and 8. Both SHR3824 and metformin tablets will be taken with 8 ounces (240 mL) of water.

Inclusion Criteria:

• Healthy volunteers with a body mass index (BMI, a measure of a person's weight in relation to height) between 19 and 24 kg/m2.

Exclusion Criteria:

• History of diabetes
• History of heart failure or renal insufficiency
• Urinary tract infections, or vulvovaginal mycotic infections
• History of or current clinically significant medical illness as determined by the Investigator
• History of clinically significant allergies, especially known hypersensitivity or intolerance to lactose
• Known allergy to SHR3824 or metformin or any of the excipients of the formulation of SHR3824 or metformin