- Participation in another clinical trial during the preceding 3 months for multiple-dose studies and 1 month for single-dose studies; (final examination from previous study to first treatment of new study).
- Exclusion periods from other studies or simultaneous participation in other clinical studies.
- Donation of >100 mL of blood within 4 weeks before the first study drug administration or >500 mL in the preceding 3 months.
- Medical disorder that would impair the subject’s ability to complete the study in the opinion of the investigator.
-Severe infection or any clinically significant illness within 4 weeks prior to dosing.
- Known hypersensitivity to the study drugs (active substances, or excipients of the preparations).
- Known severe allergies, non-allergic drug reactions, or multiple drug allergies.
-Positive results for hepatitis B virus surface antigen (HBsAg), hepatitis C virus antibodies (HCV Ab), human immune deficiency virus antibodies (HIV 1/2 Ab).
- Regular use of recreational drugs, eg carnitine products, anabolics.
- Regular daily consumption of ≥ 0.5 L of usual beer or the equivalent quantity of approximately 20 g of alcohol in another form.
-Suspicion of drug or alcohol abuse.
- Positive urine drug screening.
- Regular daily consumption of >25 cigarettes.
- Criteria which in the opinion of the investigator preclude participation for scientific reasons, for reasons of compliance, or for reasons of the subject’s safety.
- Use of medication within the 2 weeks preceding the study which could interfere with the investigational product.
-For subjects with renal impairment:
-- Acute renal failure.
-- Acute nephritis.
-- Nephrotic syndrome.
-- Any organ transplant < 1 year before participation in this study.
-- Failure of any other major organ system other than the kidney.
-- Relevant impairment in liver function of by option of the investigator.
-- Pre-existing diseases for which it can be assumed that the absorption of the study drugs will not be normal (ie relevant malabsorption, chronic diarrhea).
-- Diastolic blood pressure (DBP) >100 mmHg and/or systolic blood pressure (SBP) >180 mmHg (at the pre-study examination; readings taken at the end of the dosing interval of antihypertensive medication, if any).
-- Heart rate <45 or >100 BPM for subject aged 18 to ≤50 years and <55 or >110 BPM for subject aged >50 to ≤79 years at screening visit.
-- Significant uncorrected rhythm or conduction disturbances such as a second- or third-degree AV block without a cardiac pacemaker or episodes of sustained ventricular tachycardia, or by option of the investigator.
-- Diagnosed malignancy within the past 5 years.
-- Psychiatric disorders which may disable the subjects to consent.
--Change in chronic medications <4 weeks prior to dosing.
--Concomitant use of any medication except medications necessary for the treatment of the kidney disease or related complications.
- For healthy subjects
-- Subjects with conspicuous findings in medical history or pre-study examination by option of the investigator.
-- A history of relevant diseases of vital organs, of the central nervous system or other organs.
-- Pre-existing diseases for which it can be assumed that the absorption, distribution, metabolism, elimination and effects of the study drugs will not be normal.
-- Systolic blood pressure <100 mmHg or >145 mmHg.
-- Diastolic blood pressure >95 mmHg.
-- Heart rate <45 or >95 BPM for subject aged 18 to ≤50 years and <55 or >95 BPM for subject aged >50 to ≤79 years at screening visit.
-- Clinically relevant findings in the ECG such as a second- or third-degree AV block, clinically relevant prolongation of the QRS complex >120 ms or of the QTc interval >450 ms for men and >470 ms for women of by option of the investigator.
-- Clinically relevant deviations of the screened laboratory parameters in clinical chemistry, hematology, or urinalysis from reference range of by option of the investigator.