The study was to verify if the test formulation of Levothyroxine sodium presents an equivalent rate and extension of absorption to the comparator formulation when administered with the same dosage and under fasting conditions and after baseline correction concentrations.

Inclusion Criteria:

• To have freely agreed and signed the consent form, after all essential elements of the protocol have been clarified, before any procedure
• Body Mass Index (BMI) of the research participants must be comprised within the range of 18.50 to 27.00
• No abnormal findings on medical history that, in the opinion of the investigator, constitutes a risk or a contraindication for the participation of the participant in the study or that could interfere with the study objectives, conduct or evaluation
• Normal vital signs: heart rate between 50 and 100 beats per minute; Systolic pressure between 80 and 129 millimeters of mercury (mmHg); diastolic pressure between 50 and 89 mmHg; temperature between 36.0 and 37.0 degrees Celsius
• Electrocardiogram (ECG) normal (abnormalities, even if clinically not relevant, are not permitted [example {e.g.}: PR, QRS, QT, QTcF] should be within normal range, no conduction abnormalities etcetera [etc.])
• All values for biochemistry and hematology tests of blood and urine within the normal range or showing no clinically relevant deviation as judged by the Investigator
• Other protocol defined inclusion criteria could apply

Exclusion Criteria:

• Supplementary tests results out of the values considered as normal, unless considered clinically irrelevant
• Research participants who are submitted to surgery before the beginning of the study will be carefully evaluated by the doctor regarding the enrollment in the study complying to an exclusion period ranging from 4 to 8 weeks
• Positive test for hepatitis B, hepatitis C, or human immunodeficiency virus (HIV) in pre-study tests
• Participants with a history of hypersensitivity/allergy to study drug or excipients, history or presence of asthma or any serious allergy (requiring hospitalization or prolonged systemic treatment), any food allergy or intolerance which in the opinion of the Investigator represents a safety risk (e.g., iodine allergy, etc.)
• Has participated in any experimental trial or has taken any experimental drug within 6 months previous to this study (RDC [resolution of the collegiate board] Resolution 34, dated June 3, 2008)
• Participants that prior to the dosing takes any other medication and had not passed at least seven half-lives of elimination of the drug, in this case, be considered by the Principal Investigator the non-inclusion of the participant in the study. Participants taking medications known to affect thyroid hormone metabolism, e.g., oral contraceptives, hormonal implants, parenteral hormones, anabolic steroids, androgens, etc., or the bioavailability of levothyroxine like proton pump Inhibitors
• Has a history of alcohol abuse or has ingested alcohol 24 hours previous to the hospitalization period
• Other protocol defined exclusion criteria could apply

Per company policy, following approval of a new product or a new indication for an approved product in both the EU and the US, Merck Healthcare KGaA, Darmstadt, Germany, an affiliate of Merck KGaA, Darmstadt, Germany, will share study protocols, anonymized patient level and study level data and redacted clinical study reports from clinical trials in patients with qualified scientific and medical researchers, upon request, as necessary for conducting legitimate research. Further information on how to request data can be found on our website https://www.merckgroup.com/en/research/our-approach-to-research-and-development/healthcare/clinical-trials/commitment-responsible-data-sharing.html

Up to 79 Days; Participants were assessed for adverse events for the entire study.

Safety analysis set included all randomized participants who received one dose of study drug.