[Quinolones]

QSAR Studies, Molecular Docking, Molecular Dynamics, Synthesis, and Biological Evaluation of Novel Quinolinone-Based Thiosemicarbazones against Mycobacterium tuberculosis

In this study, a series of novel quinolinone-based thiosemicarbazones were designed in silico and their activities tested in vitro against Mycobacterium tuberculosis (M. tuberculosis). Quantitative structure-activity relationship (QSAR) studies were performed using quinolinone and thiosemicarbazide as pharmacophoric nuclei; the best model showed statistical parameters of R² = 0.83; F = 47.96; s = 0.31, and was validated by several different methods. The van der Waals volume, electron density, and electronegativity model results suggested a pivotal role in antituberculosis (anti-TB) activity. Subsequently, from this model a new series of quinolinone-thiosemicarbazone 11a-e was designed and docked against two tuberculosis protein targets: enoyl-acyl carrier protein reductase (InhA) and decaprenylphosphoryl-β-D-ribose-2'-oxidase (DprE1). Molecular dynamics simulation over 200 ns showed a binding energy of -71.3 to -12.7 Kcal/mol, suggesting likely inhibition. In vitro antimycobacterial activity of quinolinone-thiosemicarbazone for 11a-e was evaluated against M. bovis, M. tuberculosis H37Rv, and six different strains of drug-resistant M. tuberculosis. All compounds exhibited good to excellent activity against all the families of M. tuberculosis. Several of the here synthesized compounds were more effective than the standard drugs (isoniazid, oxafloxacin), 11d and 11e being the most active products. The results suggest that these compounds may contribute as lead compounds in the research of new potential antimycobacterial agents.

Development and Validation of a Sensitive HPLC Assay for Determination of Sparfloxacin According to the European Medicines Agency Guideline

Sparfloxacin, a synthetic antibiotic belonging to the third-generation fluoroquinolones, has numerous pharmacokinetic and microbiological advantages which can make it an excellent candidate for the treatment of infections in sheep. The objective of this study was to develop and validate an analytical HPLC method to quantify sparfloxacin in sheep plasma, following the recommendations set out in the Guideline on Bioanalytical Method Validation of the European Union (EMEA/CHMP/EWP/192217/2009). The HPLC mobile phase consisted of acetonitrile and monopotassium phosphate buffer (1.36 g/L) 49:51 (v/v). Genabilic acid was used as internal standard. Mean retention times for sparfloxacin and genabilic acid were 2.6 and 5.8 min, respectively. The method met all specifications of the EMA guideline, being selective and linear in the range of 0.2–10 µg/mL (R2 ≥ 0.99). Within-run precision ranged between 0.00 and 0.88%, with an accuracy of 90.3–118.0% for the lower limit of quantitation (LLOQ). The LLOQ was 0.2 µg/mL, and no interference from the biological matrix was found. The stability of sparfloxacin in the biological matrix was demonstrated under different storage conditions. Therefore, the method can be used to determine sparfloxacin concentrations in sheep plasma in different types of studies.

Pinacho D. Personalized Medicine for Antibiotics: The Role of Nanobiosensors in Therapeutic Drug Monitoring

Due to the high bacterial resistance to antibiotics (AB), it has become necessary to adjust the dose aimed at personalized medicine by means of therapeutic drug monitoring (TDM). TDM is a fundamental tool for measuring the concentration of drugs that have a limited or highly toxic dose in different body fluids, such as blood, plasma, serum, and urine, among others. Using different techniques that allow for the pharmacokinetic (PK) and pharmacodynamic (PD) analysis of the drug, TDM can reduce the risks inherent in treatment. Among these techniques, nanotechnology focused on biosensors, which are relevant due to their versatility, sensitivity, specificity, and low cost. They provide results in real time, using an element for biological recognition coupled to a signal transducer. This review describes recent advances in the quantification of AB using biosensors with a focus on TDM as a fundamental aspect of personalized medicine.

The safety of antimicrobials for the treatment of community-acquired pneumonia

Introduction: Community-acquired pneumonia (CAP) is a leading cause of morbidity and mortality worldwide, and its prevalence continues to increase. Despite the efficacy of antimicrobials, their safety and tolerability remain topics of interest and concern for clinicians and patients alike.Areas covered: This review outlines the main antimicrobial classes recommended for the empirical treatment of CAP in current guidelines, together with a potential new class. Each pharmacological group underwent a safety evaluation based on all available data about drug-related toxicities. The authors also present their mechanisms of action, their pharmacokinetic and pharmacodynamic properties, and the main clinical studies.Expert opinion: Overall, antimicrobials currently marketed for the treatment of CAP are well tolerated and generally safe. However, unusual and sometimes serious adverse effects can occur in susceptible populations. Attention should be paid to identifying patients at risk of developing drug-related toxicities because, although most effects are transient, some could be disabling, permanent, or even fatal. Post-marketing surveillance remains crucial for gathering data to overcome the limitations of preclinical and clinical studies in estimating the true prevalence of drug-related adverse events.

New and miniaturized method for analysis of enrofloxacin in palatable tablets

Enrofloxacin is an antimicrobial for oral use, from the fluoroquinolones of second-generation class, and it is the first fluoroquinolone used in veterinary for the treatment of bacterial infections. The development of trustworthy analytical methods has extreme importance for the assurance of safety, quality and therapeutic efficiency of pharmaceuticals. Previous articles in the literature describe several analytical methods for evaluation of enrofloxacin, but they do not use spectrophotometry in the visible region, nor use a miniaturized method or ecologically correct. In this work an analytical method for quantification of enrofloxacin in palatable tablets for veterinary prescriptions was developed and validated by spectrophotometry in the visible region. This method used a spectrophotometer UV-Vis BMG LabTechSpectrostar Nano, solution of iron chloride 0.5% as complexing agent, microplates and the analyses were conducted at 430 nm. The validation was conducted following international guides and showed linearity between the concentrations of 100 and 200 μg/ mL, selectivity, precision (intraday RSD 0.52%, interday RSD 0.44% and interanalyst RSD 0.56%), accuracy of 98.51% and robustness to time of analysis variation and wavelength. Therefore, the developed method approached the required parameters of validation and can be considered suitable for quantification of enrofloxacin in palatable tablets. The method also involves characteristics in green analytical chemistry for the current pharmaceutical analysis. This work contemplates a miniaturized, clean, innovator, fast and low cost method by spectrophotometry in the visible region for quantification of enrofloxacin in palatable tablets.

Intracellular penetration and activity of UB-8902 in human polymorphonuclear leukocytes

The intracellular penetration and activity of UB-8902 in human polymorphonuclear leukocytes was evaluated. Intracellular UB-8902 concentrations were 6-fold higher than extracellular levels. Uptake was rapid, reversible, saturable, and affected by external pH. UB-8902 showed intracellular activity against Staphylococcus aureus strains presenting mutations associated with fluoroquinolone resistance in the gyrA and/or grlA genes.