Tolerability Study of Liquid Metformin (100 and 250 mg/mL) vs IR Tablets

Inclusion Criteria: * Male or female adults 18 to 55 years of age, inclusive. Body mass index (BMI) between 18.0 and 30.0 kg/m², inclusive. Medically healthy based on medical history, physical examination, vital signs, clinical laboratory evaluations, and 12-lead ECG, in the opinion of the investigator. Non-smoker or light smoker (10 cigarettes per day or fewer, or equivalent) willing to abstain during study confinement periods. Able to provide written informed consent before any study-specific procedures are conducted. Willing and able to comply with all study requirements, including fasting, dosing restrictions, and safety/tolerability assessments. Females of childbearing potential must use acceptable contraception as determined by the investigator. Exclusion Criteria: * Known hypersensitivity or contraindication to metformin or any excipients in the study formulations. History or presence of clinically significant cardiovascular, hepatic, renal, gastrointestinal, endocrine, hematologic, neurologic, or psychiatric disease that, in the investigator's opinion, could interfere with participation or data interpretation. Estimated glomerular filtration rate (eGFR) \< 90 mL/min/1.73 m², or any clinically significant abnormal clinical laboratory findings. Prior history of lactic acidosis. Current or recent (within 14 days before first dose) use of prescription drugs, over-the-counter medications, herbal products, or dietary supplements, unless approved by the investigator. Positive test for hepatitis B surface antigen, hepatitis C antibody, or HIV. Positive urine drug screen or positive alcohol breath test at screening or at check-in. Participation in another clinical trial or receipt of an investigational drug or device within 30 days or 5 half-lives (whichever is longer) before first study dose. Donation of ≥450 mL of blood, or significant blood loss, within 8 weeks before the first study dose. Pregnant or breastfeeding females. Women of childbearing potential not using acceptable contraception. Any condition or finding that, in the opinion of the investigator, would make the subject unsuitable for the study.