Analytical Method Development for Evaluation of Pharmacokinetics and Tissue Distribution of Thiourea-Based Antivirals through nLC/MS-MS

Thiourea-based antivirals are organosulfur chemical compounds. Due to their various medicinal uses, including antiviral, antioxidant, and anticancer properties, they are becoming more popular. In this study, pharmacokinetics, Metabolism, bioavailability, and distribution of thiourea derivatives to organs of rats. Thiourea derivatives, namely DSA-00, DSA-02, and DSA-09, exhibit characteristics similar to those of conventional drugs when evaluated in terms of pharmacokinetics, drug-likeness, and medicinal chemistry through in-silico analysis. Then a simple and sensitive analytical method was developed for quantified DSA-00, DSA-02, and DSA-09, using prednisolone as an internal standard (IS) and nano liquid chromatography tandem mass spectrometry (nLC-MS/MS). The plasma and tissue samples were preprocessing with acetonitrile before chromatographic separation by C18 column with isocratic elution using a mobile phase of water-methanol (30:70, v/v) at a flow rate of 0.6 mL/min. A triplequadrupole tandem mass spectrometer in multiple-reaction monitoring (MRM) scanning via an electrospray ionization (ESI) source functioning in negative and positive mode detection. For DSA-00, DSA-02, DSA-09 and, internal standard the optimized mass transition ion-pairs (m/z) for quantification were 297.2, 311.2, 309.09, and 361.19 respectively. Each analytic run required only 15 minutes between injections. The calibration curve for thiourea derivatives showed good linear regression coefficient (R2 >.99) over a range of 1.00-10000 pg/mL except DSA-09. The lower limit of quantification (LLOQ) was 1.00 ng/mL. The intra- and inter-day precisions were no more than 10.8%, and relative errors (RE) ranged from 0.5 to 5.98%. The validated method was effectively used to explore the pharmacokinetics of orally administrative thiourea derivatives in rats.