Levothyroxine-sodium Bioequivalence Trial With Oral Single Dose Administration

Inclusion Criteria: 1. ethnic origin: Caucasian 2. age: 18 years or older 3. body-mass index (BMI): 18.5 kg/m² and 30.0 kg/m² 4. good state of health 5. non-smoker or ex-smoker for at least 3 months 6. written informed consent, must be signed and dated before enrolment by the subject and the (sub-)investigator, after having been informed about benefits and potential risks of the clinical trial, as well as details of the insurance taken out to cover the subjects participating in the clinical trial Exclusion Criteria: Subjects cannot be included if they match any of the following exclusion criteria: Safety concerns 1. existing cardiac, cardiovascular (e.g. angina pectoris, coronary heart disease) and/or haematological diseases or pathological findings, which might interfere with the safety or tolerability of the active ingredient 2. existing hepatic and/or renal diseases and/or endocrine diseases or pathological findings, which might interfere with the safety or tolerability, and/or pharmacokinetics of the active ingredient 3. existing lipo-metabolic disorder or pathological findings, which might interfere with the safety or tolerability, and/or pharmacokinetics of the active ingredient 4. existing gastrointestinal diseases or pathological findings, which might interfere with the safety, tolerability, absorption and/or pharmacokinetics of the active ingredient 5. any disorder of thyroid glands reported in medical history resulting in an impairment of thyroid functions 6. existing diabetes mellitus 7. current treatment with anticoagulant drugs 8. history of relevant CNS and/or psychiatric disorders and/or currently treated CNS and/or psychiatric disorders 9. existing epilepsy or current treatment with antiepileptic drugs 10. subjects with pulmonary diseases (bronchial asthma, bronchitis, COPD) or known respiratory depression 11. known allergic reactions to the active ingredients used or to constituents of the pharmaceutical preparations 12. history of significant drug allergy (especially hypersensitivity to levothyroxine-sodium) 13. subjects with severe allergies or multiple drug allergies unless it is judged as not relevant for the clinical trial by the investigator 14. systolic blood pressure \< 90 or \> 139 mmHg 15. diastolic blood pressure \< 60 or \> 89 mmHg 16. heart rate \< 50 bpm or \> 90 bpm 17. QTc interval \> 450 ms for men and \> 470 ms for women 18. laboratory values out of normal range unless the deviation from normal is judged as not relevant for the clinical trial by the investigator 19. ASAT \> 20 % ULN, ALAT \> 10 % ULN, bilirubin \> 20 % ULN (except in case of existing Morbus Gilbert-Meulengracht deduced from anamnesis/medical history) and creatinine \> 0.1 mg/dL ULN (limit of \> 0.1 mg/dL correspondents to of \> 9 µmol/l ULN). 20. positive anti-HIV-test (if positive to be verified by western blot), HBs-AG-test or anti-HCV-test 21. diagnosis of COVID-19 within the last 4 weeks and persisting disease symptoms (e.g. fever, cough) within 14 days prior to individual enrolment of the subject 22. direct contact with insufficient protection to persons in foreign risk regions for COVID-19 as defined by the Robert Koch Institute within the last 14 days prior to individual enrolment of the subject 23. known direct contact with insufficient protection to persons with diagnosis of COVID-19 within the last 14 days prior to individual enrolment upon reporting of the subject Lack of suitability for the clinical trial 24. acute or chronic diseases which may interfere with the pharmacokinetics of the IMP 25. history of or current drug or alcohol dependence 26. positive alcohol, cotinine or drug test at screening examination 27. regular intake of alcoholic food or beverages of ≥ 24 g pure ethanol for male or ≥ 12 g pure ethanol for female per day 28. subjects who are on a diet which could affect the pharmacokinetics of the active ingredient 29. regular intake of caffeine containing food or beverages of ≥ 500 mg caffeine per day 30. blood donation or other blood loss of more than 400 ml within the last 2 months prior to individual screening of the subject 31. administration of any investigational medicinal product during the last 2 months prior to individual screening of the subject 32. regular treatment with any systemically available medication (except hormonal contraceptives or common replacement therapy with estrogens). In case of treatment with hormonal contraceptives or common replacement therapy with estrogens, the treatment should have started at least 3 months prior to the first IMP administration and be regularly continued during the clinical trial. 33. current treatment with medication for malaria prophylaxis 34. subjects, who report a frequent occurrence of migraine attacks 35. radiography with contrast medium within the last 6 weeks prior to the first administration For female subjects with childbearing potential only: 36\. positive pregnancy test at screening examination 37. pregnant or lactating women 38. female subjects who do not agree to apply highly effective contraceptive methods (highly effective contraceptive methods are defined in chapter 13.2.1) Administrative reasons 39. employee or family member of the Sponsor or the involved contract research organisation (CRO) 40. vulnerable subject defined as a soldier, a subject kept in detention, a protected adult under guardianship/trusteeship or committed to an institution by governmental or juridical order 41. subjects suspected or known not to follow instructions 42. subjects who are unable to understand the written and verbal instructions, in particular regarding the risks and inconveniences they will be exposed to during their participation in the clinical trial 43. no suitable candidate in the opinion of the investigator \-