RESUMEN
This was an open-label, randomized, single-dose, 2-period, crossover clinical trial with an adaptive design to evaluate the bioequivalence and comparative pharmacokinetics of generic glecaprevir/pibrentasvir versus the brand name product in healthy White male and female volunteers under fed conditions. Safety profiles were also assessed. A total of 56 healthy adult volunteers were enrolled and randomly assigned in a 1:1 ratio to receive a single dose of either the generic or reference formulation. After a 7-day washout period, subjects received the alternate product. Blood samples were collected at pre-specified time points up to 48 hours post-dosing. Plasma concentrations of glecaprevir and pibrentasvir were determined using a validated high-performance liquid chromatography-tandem mass spectrometry method. The geometric mean ratios of the test to the reference formulation for maximum plasma concentration (Cmax) and area under the concentration-time curve from drug administration to the last measurable concentration (AUC0-t) fell within the predefined bioequivalence range of 80%-125%. Both formulations demonstrated comparable pharmacokinetic profiles for glecaprevir and pibrentasvir, and can be considered bioequivalent. No adverse events were reported, and both formulations were well tolerated by all participants.
RESUMEN
Molnupiravir is an antiviral drug against viral RNA polymerase activity approved by the FDA for the treatment of COVID-19, which is metabolized to ß-D-N4-hydroxycytidine (NHC) in human blood plasma. A novel method was developed and validated for quantifying NHC in human plasma within the analytical range of 10-10,000 ng/mL using high-performance liquid chromatography with tandem mass spectrometry (HPLC-MS/MS) to support pharmacokinetics studies. For sample preparation, the method of protein precipitation by acetonitrile was used, with promethazine as an internal standard. Chromatographic separation was carried out on a Shim-pack GWS C18 (150 mm × 4.6 mm, 5 µm) column in a gradient elution mode. A 0.1% formic acid solution in water with 0.08% ammonia solution (eluent A, v/v) and 0.1% formic acid solution in methanol with 0.08% ammonia solution mixed with acetonitrile in a 4:1 ratio (eluent B, v/v) were used as a mobile phase. Electrospray ionization (ESI) was used as an ionization source. The developed method was validated in accordance with the Eurasian Economic Union (EAEU) rules, based on the European Medicines Agency (EMA) and Food and Drug Administration (FDA) guidelines for the following parameters and used within the analytical part of the clinical study of molnupiravir drugs: selectivity, suitability of standard sample, matrix effect, calibration curve, accuracy, precision, recovery, lower limit of quantification (LLOQ), carryover, and stability.