- clinically relevant history of abnormal physical or mental health (defined as any subject requiring medical, psychological or pharmacotherapeutic intervention for mental illness) interfering with the study as determined by medical history and physical examinations obtained during screening and day -1 as judged by the investigator (including [but not limited to], neurological, psychiatric, endocrine, cardiovascular, respiratory, gastrointestinal, hepatic, or renal disorder). - any other concomitant disease or condition that could interfere with, or for which the treatment might interfere with, the conduct of the study as outlined in this protocol, or that would, in the opinion of the investigator, pose an unacceptable risk to the subject in this study. - evidence of previous sars-cov-2 infection from medical history. - ophthalmologic disorder (moderate and sever retina or optic nerve pathology; cataracts excluded). - subjects with a diagnosis of asthma or any other respiratory conditions. - a neurologic disorder that may compromise blood brain barrier permeability (stroke within 90 days, brain tumour, multiple sclerosis, or other neuroinflammatory condition, a neurodegenerative disorder, epilepsy) or history of seizures. - positive test for hepatitis b surface antigen (hbsag), anti-hepatitis c antibody (anti-hcv) or human immunodeficiency virus i and ii (anti-hiv i/ii) at screening. - the subject has participated in a clinical study and has received a medication or a new chemical entity within 3 months or 5 half-lives (whichever is longer) prior to first dosing of current study medication. - use of any drugs that are known substrates of cyp3a4, p-glycoprotein (p-gp) from within 4 weeks of screening and unable to refrain from them until the end of the study (e.g., rifampicin, quinidine, amiodarone, diltiazem, spironolactone, verapamil, clarithromycin, erythromycin, itraconazole, ketoconazole, cyclosporine, tacrolimus, indinavir, ritonavir or cobicistat). use of critical cyp3a4 substrate drugs such as warfarin or coumarin anticoagulants. - recent or expected microfilaricidal drug use, including ivermectin, or travel history to areas that are endemic for loa loa or onchocerciasis (angola, cameroon, central african republic, chad, democratic republic of congo, ethiopia, equatorial, guinea, gabon, republic of congo, nigeria and sudan). - use of medications having potential activity against sars-cov-2 such as hydroxychloroquine, chloroquine, lopinavir, ritonavir, remdesivir, azithromycin, in the 30 days prior to screening and unable to refrain from them until the end of the study. - consumption of any food or drinks containing cranberry, pomegranate, starfruit, grapefruit, pomelos, exotic citrus fruits or seville oranges (including marmalade and juices made from these fruits) within 14 days prior to first dosing until the end of the study.

- clinically relevant history of abnormal physical or mental health (defined as any subject requiring medical, psychological or pharmacotherapeutic intervention for mental illness) interfering with the study as determined by medical history and physical examinations obtained during screening and day -1 as judged by the investigator (including [but not limited to], neurological, psychiatric, endocrine, cardiovascular, respiratory, gastrointestinal, hepatic, or renal disorder). - any other concomitant disease or condition that could interfere with, or for which the treatment might interfere with, the conduct of the study as outlined in this protocol, or that would, in the opinion of the investigator, pose an unacceptable risk to the subject in this study. - evidence of previous sars-cov-2 infection from medical history. - ophthalmologic disorder (moderate and sever retina or optic nerve pathology; cataracts excluded). - subjects with a diagnosis of asthma or any other respiratory conditions. - a neurologic disorder that may compromise blood brain barrier permeability (stroke within 90 days, brain tumour, multiple sclerosis, or other neuroinflammatory condition, a neurodegenerative disorder, epilepsy) or history of seizures. - positive test for hepatitis b surface antigen (hbsag), anti-hepatitis c antibody (anti-hcv) or human immunodeficiency virus i and ii (anti-hiv i/ii) at screening. - the subject has participated in a clinical study and has received a medication or a new chemical entity within 3 months or 5 half-lives (whichever is longer) prior to first dosing of current study medication. - use of any drugs that are known substrates of cyp3a4, p-glycoprotein (p-gp) from within 4 weeks of screening and unable to refrain from them until the end of the study (e.g., rifampicin, quinidine, amiodarone, diltiazem, spironolactone, verapamil, clarithromycin, erythromycin, itraconazole, ketoconazole, cyclosporine, tacrolimus, indinavir, ritonavir or cobicistat). use of critical cyp3a4 substrate drugs such as warfarin or coumarin anticoagulants. - recent or expected microfilaricidal drug use, including ivermectin, or travel history to areas that are endemic for loa loa or onchocerciasis (angola, cameroon, central african republic, chad, democratic republic of congo, ethiopia, equatorial, guinea, gabon, republic of congo, nigeria and sudan). - use of medications having potential activity against sars-cov-2 such as hydroxychloroquine, chloroquine, lopinavir, ritonavir, remdesivir, azithromycin, in the 30 days prior to screening and unable to refrain from them until the end of the study. - consumption of any food or drinks containing cranberry, pomegranate, starfruit, grapefruit, pomelos, exotic citrus fruits or seville oranges (including marmalade and juices made from these fruits) within 14 days prior to first dosing until the end of the study.