Development and validation of LC-MS/MS methods for the simultaneous quantification of sofosbuvir and its major metabolite (GS-331007) in blood plasma and cerebrospinal and seminal fluid: Application to a pilot clinical trial with a focus on Zika.

Zika still poses a threat to global health owing to its association with serious neurological conditions and the absence of a vaccine and treatment. Sofosbuvir, an anti-hepatitis C drug, has shown anti-Zika effects in animal and cell models. Thus, this study aimed to develop and validate novel LC-MS/MS methods for the quantification of sofosbuvir and its major metabolite (GS-331007) in human plasma and cerebrospinal (CSF) and seminal fluid (SF), and apply the methods to a pilot clinical trial.

Atazanavir Is a Competitive Inhibitor of SARS-CoV-2 M, Impairing Variants Replication In Vitro and In Vivo.

Atazanavir (ATV) has already been considered as a potential repurposing drug to 2019 coronavirus disease (COVID-19); however, there are controversial reports on its mechanism of action and effectiveness as anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Through the pre-clinical chain of experiments: enzymatic, molecular docking, cell-based and in vivo assays, it is demonstrated here that both SARS-CoV-2 B.1 lineage and variant of concern gamma are susceptible to this antiretroviral.

Pharmacokinetics of chloroquine and primaquine in healthy volunteers.

Background: Vivax malaria is a neglected disease. There is an irrefutable need for better treatments with higher acceptability and efficacy. The treatment efficacy is influenced by many factors, including bioavailability.

Pharmacological profiling of JME-173, a novel mexiletine derivative combining dual anti-inflammatory/anti-spasmodic functions and limited action in Na channels.

Existing evidence suggests that the local anaesthetic mexiletine can be beneficial for patients with asthma. However, caution is required since anaesthesia of the airways inhibits protective bronchodilator neuronal reflexes, limiting applications in conditions of hyperirritable airways. Here, we describe the synthesis of a new series of mexiletine analogues, which were screened for reduced activity in Na channels and improved smooth muscle relaxant effects, that were evaluated using the patch-clamp technique and an isolated tracheal organ bath, respectively.

Pharmacokinetics/pharmacodynamics of chloroquine and artemisinin-based combination therapy with primaquine.

Background: Activation of hypnozoites of vivax malaria causes multiple clinical relapses, which contribute to the Plasmodium vivax burden and continuing transmission. Artemisinin-based combination therapy (ACT) is effective against blood-stage P. vivax but requires co-administration with primaquine to achieve radical cure.

Cynomolgus monkeys are successfully and persistently infected with hepatitis E virus genotype 3 (HEV-3) after long-term immunosuppressive therapy.

Epidemiological studies found that hepatitis E virus genotype 3 (HEV-3) infection was associated with chronic hepatitis and cirrhosis in immunocompromised patients. Our study aimed to investigate the relationship between the host immunosuppressive status and the occurrence of HEV-related chronic hepatitis. Here we describe a successful experimental study, using cynomolgus monkeys previously treated with tacrolimus, a potent calcineurin inhibitor immunosuppressant, and infected with a Brazilian HEV-3 strain isolated from naturally infected pigs.

Development and validation of a discriminative dissolution test for nimesulide suspensions.

The dissolution test for oral dosage forms has recently widened to a variety of special dosage forms such as suspensions. For class II drugs, such as nimesulide (NMS), this study is very important because formulation problems may compromise drug bioavailability. In the present work, tests with four brands of commercially available NMS (RA, TS, TB, and TC) have been performed in order to study their dissolution at different conditions.