Structural characterization of degradation products of phenol red used as zero permeability marker in in-situ rat intestinal permeability studies by LCMS-IT-TOF.

In this study, the quantitative determination of phenol red with using HPLC, the permeability marker widely used in gastrointestinal studies, and its stability in various apolar phase solvents were investigated. In addition, the mechanisms of degradation products obtained were tried to be elucidated by using the LCMS-IT-TOF device. The proposed HPLC method utilizes a Perkin Elmer C, 5 μm, 250 mm × 4.

Favipiravir pharmacokinetics in COVID-19 patients with moderate to severe kidney dysfunction: Lessons learned.

Objective: There is limited information on favipiravir pharmacokinetics in critically ill patients and no studies on pharmacokinetics in patients with moderate and severe kidney dysfunction. The aim was to determine favipiravir pharmacokinetics (oral, 1,600 mg, q12h on day 1, then 600 mg, q12h for 4 days) in critically ill COVID-19 patients with kidney dysfunction and to compare those with observations reported in healthy adults.

Materials And Methods: In a descriptive study, blood samples taken from patients meeting the relevant criteria (estimated glomerular filtration rate < 60 mL/min) were collected and analyzed.

Adapting Fabric Phase Sorptive Extraction as an Innovative Multitool for Sample Transfer and Extraction in Pharmacokinetic Analysis Followed by LC-MS Determination of Levofloxacin in Plasma Samples.

Fabric phase sorptive extraction (FPSE) is a simple microextraction technique that allows analytes to be rescued from matrix components while using a small volume of samples to analyze complex biological systems. This study used FPSE as a microextraction tool and a sample storage and transfer device. Levofloxacin as a model molecule was applied intravenously (IV) to New Zealand male rabbits.