Phase I Pharmacokinetics Study of Oral Administration of Esperavir® (INN: Molnupiravir) (LLC "PROMOMED RUS", Russia)

Introduction. The pandemic of the new coronavirus infection COVID-19 (Coronavirus Disease 2019) was caused by a single-stranded RNA virus SARS-CoV-2 (Severe acute respiratory syndrome-related coronavirus 2). Molnupiravir is an antiviral drug with activity against RNA viruses including SARS-CoV-2. Molnupiravir exerts the antiviral effect by introducing copy errors during viral RNA replication – by that the replication of SARS-CoV-2 inhibits. For oral administration of molnupiravir the drug Esperavir® has been registered in Russia.Aim. The aim is pharmacokinetics study of Esperavir®, capsules 200 mg (the manufacturer is JSC "Biokhimic", LLC "PROMOMED RUS", Russia, as registration certificate holder) by a single dose (800 mg) and multiple doses oral administration (800 mg twice a day with a gap of 12 hours between doses) in healthy volunteers in a phase I pharmacokinetics study, comparison the obtained data of pharmacokinetic parameters with the literature data.Materials and methods. The clinical and analytical phases of the pharmacokinetic study as well as pharmacokinetic analyses have been performed as a part of a clinical trial of the drug Esperavir®, capsules 200 mg (the manufacturer is JSC "Biokhimic", LLC "PROMOMED RUS", Russia, as registration certificate holder). Chromatographic separation and detection by Nexera XR high-performance liquid chromatograph with triple quadrupole tandem mass spectrometry LCMS-8040 (Shimadzu Corporation, Japan). The pharmacokinetic parameters were calculated with the Boomer pharmacokinetic analysis add-in for Microsoft Excel (Department of Pharmacokinetics and Drug Metabolism, Allergan, Irvine, CA 92606, USA). Descriptive pharmacokinetic statistics were calculated with Microsoft Excel (Microsoft Corporation, USA).Results and discussion. Pharmacokinetic parameters for cohort 1 (800 mg single dose of Esperavir®) and for cohort 2 (800 mg of Esperavir® twice a day with a gap of 12 hours between doses) were calculated. Averaged pharmacokinetic profiles of mean NHC concentrations over time in linear and log-linear scales were plotted. The geometric mean of Cmax and T1/2, the median, minimum and maximum of Tmax showed the comparability of the obtained data after a single dose administration of 800 mg of Esperavir® and the available literature data.Conclusion. According to the concentrations from the analytical phase of the pharmacokinetic study the pharmacokinetic parameters were calculated, averaged pharmacokinetic profiles in linear and log-linear scales were plotted after a single dose and multiple doses of the drug Esperavir®, capsules (the manufacturer is JSC "Biokhimic", LLC "PROMOMED RUS", Russia, as registration certificate holder). The comparability of the obtained data and the available literature data was shown. The results justified the study of the subsequent phases of clinical trials of Esperavir®.