Pharmacokinetic Research Articles

In Silico Design of Novel Piperazine-Based mTORC1 Inhibitors Through DFT, QSAR and ADME Investigations

Mammalian target of rapamycin complex 1 (mTORC1) is an important and promising alternative biological target for the treatment of different types of cancer including breast, lung and renal cell carcinoma. This study contributed to the development of mathematical models highlighting the quantitative structure-activity relationship of a series of piperazine derivatives reported as mTORC1 inhibitors. Various molecular descriptors were calculated using Gaussian 09, Chemsketch, and ChemOffice software. The density funcional theory (DFT) method at the level B3LYP/6-31G+(d, p) was applied to determine the structural, electronic and energetic parameters associated with the studied molecules. The predictive ability of the built models, which is obtained by two methods (MLR and MNLR), showed that the built models are statistically significant. The QSAR modeling results revealed that the six molecular descriptors of lowest unoccupied molecular orbital energy (ELUMO), electrophilicity index (ω), molar refractivity (MR), aqueous solubility (Log S), topological polar surface area (PSA), and refractive index (n) significantly correlated to the biological inhibitory activity of piperazine derivatives. Using QSAR models and in silico pharmacokinetic profiles predictions, five new candidate compounds are selected as potential inhibitors against cancer.

The FSGS protein actinin-4 (ACTN4) interacts with NKCC2 to regulate Thick Ascending Limb (TAL) NaCl reabsorption.

In the kidney, the thick Ascending Limb (TAL) of the loop of Henle is crucial for NaCl homeostasis and blood pressure regulation. In animal models of salt-sensitive hypertension, NaCl reabsorption via the apical Na+/K+/2Cl cotransporter (NKCC2) is abnormally increased in the TAL. We showed that NaCl reabsorption is controlled by the presence of NKCC2 at the apical surface of TALs. However, the molecular mechanisms that maintain the steady-state levels of NKCC2 at the apical surface are not clearly understood. Here, we report that NKCC2 interacts with the F-actin cross-linking protein actinin-4 (ACTN4). We find that ACTN4 is expressed in TALs by Western blot and immunofluorescence microscopy. ACTN4 immunoprecipitated with NKCC2 and recombinant GST-ACTN4 pulled down NKCC2 from TAL lysates. ACTN4 is involved in endocytosis in other cells. Therefore, we hypothesized that ACTN4 binds apical NKCC2 and regulates its trafficking. To study this, we silenced ACTN4 in vivo via shRNA or CRISPR/Cas9 system to decrease ACTN4 expression in TALs. We observed that silencing ACTN4 in vivo via shRNA or CRISPR/Cas9 system increased the amount NKCC2 at the apical surface of TALs. Bumetanide-induced diuresis and natriuresis were enhanced by 35% after silencing of ACTN4 in vivo (AV-NKCC2-Cas9: 3841±709 vs AAV-gRNA-ACTN4: 5546±622 µmols Na/8h, n=5, p<0.05). We conclude that ACTN4, binds NKCC2 to regulate its surface expression. Selective depletion of ACTN4 in TALs using shRNA or CRISPR/Cas9 enhances surface NKCC2 and TAL NaCl reabsorption, indicating that regulation of the ACTN4-NKCC2 interaction is important for renal NaCl reabsorption and could be related to hypertension.

Cheminformatics-aided discovery of potential allosteric site modulators of ubiquitin-specific protease 7

Ubiquitin-specific peptidase 7 (USP7) is a deubiquitinating enzyme that mediates the stability and activity of numerous proteins. At basal expression levels, USP7 stabilizes p53 protein, even in the presence of excess MDM2. However, its overexpression leads to the deubiquitination of MDM2 at a rate faster than p53, leading to p53 degradation and pro-tumorigenic roles. Consequently, it is an attractive target for anticancer drug discovery via the modulation of its allosteric site from which the protein is activated. In this study, molecular modeling techniques and cheminformatics approaches were employed to unravel the potential of eighty compounds to serve as its allosteric site modulators. The compounds were initially subjected to virtual screening. Subsequently, the binding free energies of the top four compounds with the highest binding affinities were calculated, and their drug-likeness, and pharmacokinetic and toxicity profiles were evaluated. Ultimately, the complexes of the protein and hit compounds were subjected to a 100 nanoseconds (ns) molecular dynamics simulation. The results of the study revealed eight compounds from the compound library with docking scores ranging from − 7.491 to -11.43 kcal/mol, compared to P217564, which exhibited a docking score of -5.671 kcal/mol. The top four compounds with the highest affinities possessed drug-like properties, and good pharmacokinetic and toxicity profiles, and their predicted inhibitory potentials showed they will be effective at minimal concentration. Also, molecular dynamics simulation confirmed the stability of the protein-ligand complexes. Conclusively, the compounds identified in this study are worthy of further evaluation for the development of allosteric site modulators of USP7.

Design of some phthalazine molecules as novel VEGFR-2 target inhibitors through 3D-QSAR modeling, molecular docking and dynamic simulation and pharmacokinetics profiling

AbstractBreast cancer is one of the dominant cause of cancer-related mortality in females, with an incidence of approximately 1.3 million cases annually, necessitating the development of effective therapeutic strategies. In this study, 3D-QSAR models were reported based on Phthalazine derivatives as VEGFR-2 inhibitors. The activities of these derivatives were correlated with the steric (S), electrostatic (E), hydrogen bond acceptor (A), and donor (D), and hydrophobic (H) fields, which served as critical parameters in model development. Statistical studies of these models showed that the best models are; CoMFA_S (Q2 = 0.623, R2 = 0.941), and CoMSIA_E + D (Q2 = 0.615, R2 = 0.977). Based on the insights from the model fields and docking simulation of the template (compound 17), twelve molecules were designed. These novel molecules exhibited stronger potency compared to the template and the standard, Sorafenib. Compound 17A emerged as the most potent, with pIC50 = 5.98, for CoMFA_S and 5.85, for CoMSIA_E + D, and a strong docking affinity of − 97.271 kcal/mol, therefore subjected to a 100-ns MD simulation. Results indicate better interaction and stabilizing potential over Sorafenib, due to the lower RMSD, RMSF, Rg, values and favorable hydrogen bond analyses. These conclusions were validated by Gibbs free energy analysis and MM-GBSA calculations, revealing a more favorable interaction free energy of − 18.48 kcal/mol related to Sorafenib. Furthermore, these designed compounds demonstrated promising pharmacokinetic profiles.

Clinical Development of the GluN2B-selective NMDA Receptor Inhibitor NP10679 for the Treatment of Neurologic Deficit after Subarachnoid Hemorrhage.

Aneurysmal subarachnoid hemorrhage (aSAH) may be associated with cerebral vasospasm, which can lead to delayed cerebral ischemia, infarction, and worsened functional outcomes. The delayed nature of cerebral ischemia secondary to SAH-related vasculopathy presents a window of opportunity for the evaluation of well-tolerated neuroprotective agents administered soon after ictus. Secondary ischemic injury in SAH is associated with increased extracellular glutamate, which can overactivate NMDA receptors (NMDARs), thereby triggering NMDAR-mediated cellular damage. In this study, we have evaluated the effect of the pH-sensitive GluN2B-selective NMDAR inhibitor, NP10679, on neurologic impairment after SAH. This compound demonstrates a selective increase in potency at the acidic extracellular pH levels that occur in the setting of ischemia. We found that NP10679 produced durable improvement of behavioral deficits in a well-characterized murine model of SAH, and these effects were greater than those produced by nimodipine alone, the current standard of care. In addition, we observed an unexpected reduction in SAH-induced luminal narrowing of the middle cerebral artery. Neither nimodipine nor NP10679 alter each other's pharmacokinetic profile, suggesting no obvious drug-drug interactions. Based on allometric scaling of both toxicological and efficacy data, the therapeutic margin in man should be at least 2. These results further demonstrate the utility of pH-dependent neuroprotective agents and GluN2B-selective NMDAR inhibitors as potential therapeutic strategies for the treatment of aSAH. Significance Statement This report describes the properties and utility of the GluN2B-selective pH-sensitive NMDA receptor inhibitor, NP10679, in a well-characterized rodent model of subarachnoid hemorrhage. We show that the administration of NP10679 improves long-term neurological function following subarachnoid hemorrhage, and that in rats there are no drug-drug interactions between NP10679 and nimodipine, the standard of care for this indication.

An IQ Industry Perspective on Informing Dosing Recommendations in Patients With Renal Impairment.

The IQ CPLG Organ Impairment WG conducted a survey to understand how various IQ member companies develop dosing recommendations for patients with renal impairment. Eighteen IQ member companies participated in the survey. The survey results were summarized by the working group in light of the regulatory renal impairment guidance documents as well as recent publications from the pharmaceutical industry and nephrology community. There were two important learnings from the survey: (i) pharmaceutical companies do not use a consistent methodology to assess renal function in their drug development programs. (ii) there has been significant improvement in predicting how kidney function affects drug pharmacokinetics (PK) and thus dose recommendations. Applying model-based methods such as population PK, physiologically-based PK (PBPK), and virtual controls has enabled earlier prediction of how kidney function influences PK, leading to the participation of more patients with impaired kidney function in Phase 2 and 3 trials.

Evaluation of Alpha-Synuclein and Tau Antiaggregation Activity of Urea and Thiourea-Based Small Molecules for Neurodegenerative Disease Therapeutics.

Alzheimer's disease (AD) and Parkinson's disease (PD) are multifactorial, chronic diseases involving neurodegeneration. According to recent studies, it is hypothesized that the intraneuronal and postsynaptic accumulation of misfolded proteins such as α-synuclein (α-syn) and tau, responsible for Lewy bodies (LB) and tangles, respectively, disrupts neuron functions. Considering the co-occurrence of α-syn and tau inclusions in the brains of patients afflicted with subtypes of dementia and LB disorders, the discovery and development of small molecules for the inhibition of α-syn and tau aggregation can be a potentially effective strategy to delay neurodegeneration. Urea is a chaotropic agent that alters protein solubilization and hydrophobic interactions and inhibits protein aggregation and precipitation. The presence of three hetero atoms (O/S and N) in proximity can coordinate with neutral, mono, or dianionic groups to form stable complexes in the biological system. Therefore, in this study, we evaluated urea and thiourea linkers with various substitutions on either side of the carbamide or thiocarbamide functionality to compare the aggregation inhibition of α-syn and tau. A thioflavin-T (ThT) fluorescence assay was used to evaluate the level of fibril formation and monitor the anti-aggregation effect of the different compounds. We opted for transmission electron microscopy (TEM) as a direct means to confirm the anti-fibrillar effect. The oligomer formation was monitored via the photoinduced cross-linking of unmodified proteins (PICUP). The anti-inclusion and anti-seeding activities of the best compounds were evaluated using M17D intracellular inclusion and biosensor cell-based assays, respectively. Disaggregation experiments were performed with amyloid plaques extracted from AD brains. The analogues with indole, benzothiazole, or N,N-dimethylphenyl on one side with halo-substituted aromatic moieties had shown less than 15% cutoff fluorescence obtained with the ThT assay. Our lead molecules 6T and 14T reduced α-syn oligomerization dose-dependently based on the PICUP assays but failed at inhibiting tau oligomer formation. The anti-inclusion effect of our lead compounds was confirmed using the M17D neuroblastoma cell model. Compounds 6T and 14T exhibited an anti-seeding effect on tau using biosensor cells. In contrast to the control, disaggregation experiments showed fewer Aβ plaques with our lead molecules (compounds 6T and 14T). Pharmacokinetics (PK) mice studies demonstrated that these two thiourea-based small molecules have the potential to cross the blood-brain barrier in rodents. Urea and thiourea linkers could be further improved for their PK parameters and studied for the anti-inclusion, anti-seeding, and disaggregation effects using transgenic mice models of neurodegenerative diseases.

A Sequential Population Pharmacokinetic Model of Zilovertamab Vedotin in Patients with Hematologic Malignancies Extrapolated to the Pediatric Population.

Recently a number of antibody-drug conjugate (ADC) pharmacometric models have been reported in the literature, describing one or two ADC-related analytes. The objective of this analysis was to build a population pharmacokinetic (popPK) three-analyte ADC model to describe efficacy and safety of zilovertamab vedotin, an ROR1-targeting ADC conjugated to monomethyl auristatin E (MMAE). Data from a phase 1 study of zilovertamab vedotin in subjects with hematologic malignancies was used in a stepwise ADC modeling strategy based on the simplified ADC popPK model proposed by Gibiansky. This choice provided opportunity to model three analytes: conjugated monomethyl auristatin E (acMMAE), total monoclonal antibody (total mAb), and free MMAE. The model was extrapolated to the pediatric population using a clearance maturation function and accounting for weight dependent pharmacokinetic (PK) changes. The simplified model provided a good structure to fit the adult acMMAE, total mAb, and free MMAE data. Analysis showed that MMAE was released through deconjugation of the payload and full proteolytic degradation of the acMMAE. Deconjugation was associated with an immediate release of MMAE, proteolytic clearance introduced a delay in the release of MMAE. Simulation of the model extrapolated to the pediatric population was the basis for pediatric dosing strategies forzilovertamab vedotinthat were approved in the United States and European Union. The total mAb, acMMAE, and free MMAE model showed a good fit to the data. The pediatric population can match the acMMAE adult exposure at the same weight-based dose regimen without concerns that the toxic MMAE concentration will reach higher levelsthan found in adults.

Medicinal chemistry insights in neuronal nitric oxide synthase inhibitors containing nitrogen heterocyclic compounds: a mini review.

Many scientific reports over the last two decades have focused on the discovery and development of novel nNOS inhibitors. The structural identity of isoforms, bioavailability, pharmacokinetic, and safety profile issues remain major obstacles in the discovery of more potent and selective nNOS inhibitors. This review aims to provide an in-depth overview of the molecular interaction patterns between nNOS active site and inhibitors containing structurally diverse nitrogen heterocyclic compounds and highlight the structural properties needed to develop selective nNOS inhibitors. Previously published data allowed the usage of the structure-driven approach in the designing of selective nNOS inhibitors, which relies on the specific structural features required to achieve isoform-selectivity towards nNOS. The incorporation of chiral pyrrolidine ring, two aminopyridine heads, or a specific amino tail group, along with the inhibitor's capacity to adopt the curled conformation in the nNOS environment significantly strengthens the molecular interaction between the inhibitor and nNOS residues by forming specific electrostatic interactions and non-bonded contacts that are vital for isoform selectivity. Additional structure-activity relationship investigations are necessary to elucidate more structural characteristics that will ultimately resolve the exact structural basis required for isoform-selective inhibition of nNOS.

First-in-human dose escalation study of the first-in-class PDE3A-SLFN12 complex inducer BAY 2666605 in patients with advanced solid tumors co-expressing SLFN12 and PDE3A.

To evaluate the safety, tolerability, and pharmacokinetics of BAY 2666605, a velcrin that induces complex formation between the phosphodiesterase PDE3A and the protein Schlafen 12 (SLFN12) leading to a cytotoxic response in cancer cells. This was a first-in-human phase I study of BAY 2666605 (NCT04809805), an oral, potent first-in-class PDE3A-SLFN12 complex inducer, with reduced PDE3A inhibition. Adults with advanced solid tumors that co-express SLFN12 and PDE3A received BAY 2666605 at escalating doses starting at 5 mg once daily in 28-day cycles. Forty-seven patients were pre-screened for SLFN12 and PDE3A overexpression, and 5 biomarker-positive patients received ≥ 1 BAY 2666605 dose. The most common adverse event was grade 3-4 thrombocytopenia in 3 of the 5 patients treated. The long half-life (> 360 hours) and associated accumulation of BAY 2666605 led to the selection of an alternative schedule consisting of a loading dose with QD maintenance dose. The maximum tolerated dose was not established as the highest doses of both schedules were intolerable. No objective responses were observed. Due to the high expression of PDE3A in platelets compared to tumor tissues, the ex vivo dose-dependent inhibitory effect of BAY 2666605 on megakaryocytes, and the pharmacokinetic profile of the compound, alternative schedules were not predicted to ameliorate the mechanism-based thrombocytopenia. Despite the decreased PDE3A enzymatic inhibition profile of BAY 2666605, the occurrence of thrombocytopenia in treated patients, an on-target effect of the compound, precluded the achievement of a therapeutic window, consequently leading to trial termination.

Single-dose and steady-state pharmacokinetics of clomipramine, yohimbine and clomipramine/yohimbine combination: A clinical drug-drug interaction study.

Clomipramine (CLOMI) has shown effectiveness in treating premature ejaculation but is linked to erectile dysfunction and reduced libido. Yohimbine (YOH), by contrast, is effective in treating erectile dysfunction and may improve libido. Combining CLOMI and YOH could potentially leverage the benefits of both drugs. This study aimed to investigate the interactions between these drugs and to evaluate their safety profile. A prospective, open-labelled, single-centre, pharmacokinetic (PK) drug-drug interaction study was performed in 15 healthy male subjects. Single-dose and steady-state PK were investigated using noncompartmental analysis after mono- and combination therapy of the 2 orally applied drugs. Plasma sampling was performed at baseline, 0.5 (YOH), 1, 1.5 (YOH), 2, 3, 4, 5, 6, 8, 12 and 24 h (CLOMI). Differences in the area under the curve after multiple dosing (MD) were determined using an equivalence boundary of 80-125%. The geometric mean ratio of the area under the curve up to 12 h for MD CLOMI (combination vs. monotherapy) was 112% (90% confidence interval: 104-120%), whereas for MD YOH this ratio was 137% (90% confidence interval: 112-168%). The study drugs were safe and well tolerated as mono- and combination therapy, with no major adverse events reported. A PK assessment of clomipramine and yohimbine indicated a clinically significant drug-drug interaction for MD YOH in combination with CLOMI. This might be explained by competitive, CLOMI-related inhibition of YOH metabolism, probably mediated by cytochrome P450 2D6. However, according to European Medicines Agency guidelines, the effect can be classified as interaction absent (<1,25 fold) or minor (>1.25-<2-fold). Given the complimentary mechanisms of action and the favourable safety profiles, the findings pave the way for future efficacy studies.

Pharmacokinetics and Bioequivalence of Two Powders of Azithromycin for Suspension: A Nonblinded, Single-Dose, Randomized, Three-Way Crossover Study in Fed and Fasting States Among Healthy Chinese Volunteers.

Azithromycin, a macrolide antibiotic, is commonly used to treat mild-to-moderate bacterial infections. This research aimed to evaluate the pharmacokinetics (PK) properties and bioequivalence (BE) of two azithromycin (EQ 100 mg base/packet) powders for suspension in Chinese healthy participants in fed and fasting conditions. A total of 90 Chinese healthy participants were enrolled in this nonblinded, single-dose, randomized, semireplicate, three-period, three-sequence, crossover study. Of them, 42 and 40 were categorized to the fed and fasting conditions, respectively. The washout period between doses was 21 days. Blood specimens were harvested prior to administering the drug and 194 h following administration. The plasma levels of azithromycin were analyzed using a validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) approach. PK parameters were measured using noncompartmental analysis. This research compared BE between the reference and test products using the average bioequivalence (ABE) or reference-scaled average bioequivalence (RSABE) method, considering the within-subject variability (SWR) of the reference preparation. Adverse events (AEs) were monitored to examine safety and tolerability. The RSABE method (SWR ≥ 0.294) was used to determine the BE of maximal plasma concentration (Cmax) in both fed and fasting conditions. In the ABE approach, (SWR < 0.294) was adopted to assess the BE of the area under the plasma concentration-time curve from time zero to the last measurable time point (AUC0-t) and determine the area under the plasma concentration time curve from time zero to time infinity (AUC0-inf). In the fasting condition, the point estimate of the test/reference ratio for Cmax was 1.08, with a 95% upper confidence bound of - 0.05 < 0.00. The geometric mean ratio (GMRs) for AUC0-t and AUC0-inf was 115.21% [90% confidence interval (CI) 107.25-123.27%] and 113.07% (90% CI 105.14-121.61%), respectively. In the fed condition, the point estimate of the test/reference ratio for Cmax was 0.94, with a 95% upper confidence bound of - 0.10 < 0.00. The GMR for AUC0-t and AUC0-inf was 99.51% (90% CI of 91.03-108.78%) and 99.43% (90% CI 91.73-107.78%), respectively. These data all satisfied the BE criteria for drugs with high variability. All AEs were transient and mild, and no severe AEs were observed. Our study indicated that the test and reference products of azithromycin (EQ 100 mg base/packet) powder for suspension were bioequivalent and safe in healthy Chinese participants, irrespective of the feeding condition. CLINICAL TRIAL REGISTRATION (CHINADRUGTRIALS.ORG.CN): CTR20232646, registered on 25 August 2023.

Dietary Flavonoid Chrysin Functions as a Dual Modulator to Attenuate Amyloid-β and Tau Pathology in the Models of Alzheimer's Disease.

Growing evidence indicates that healthy diets are associated with a slower progression of Alzheimer's disease (AD). Flavonoids are among the most abundant natural products in diets beneficial to AD, such as the Mediterranean diet. However, the effect and mechanism of these dietary flavonoids on AD remains incompletely understood. Here, we found that a representative dietary natural flavonoid, chrysin (Chr), significantly ameliorated cognitive impairment and AD pathology in APP/PS1 mice. Furthermore, mechanistic studies showed that Chr significantly reduced the levels of amyloid-β (Aβ) and phosphorylated tau (p-tau), along with dual inhibitory activity against β-site amyloid precursor protein cleaving enzyme 1 (BACE1) and glycogen synthase kinase 3β (GSK3β). Moreover, the effect of Chr was further confirmed by EW233, a structural analog of Chr that exhibited an improved pharmacokinetic profile. To further verify the role of Chr and EW233, we utilized our previously established chimeric human cerebral organoid (chCO) model for AD, in which astrogenesis was promoted to mimic the neuron-astrocyte ratio in human brain tissue, and similar dual inhibition of Aβ and p-tau was also observed. Altogether, our study not only reveals the molecular mechanisms through which dietary flavonoids, such as Chr, mitigate AD pathology, but also suggests that identifying a specific constituent that mimics some of the benefits of these healthy diets could serve as a promising approach to discover new treatments for AD.

Towards the understanding of the IVPT results variability—Development, verification and validation of the PBPK model of caffeine in vitro human skin permeation

In the context of evaluating the safety and efficacy of dermal products, pharmacokinetic (PK) studies face considerable challenges, particularly concerning topically applied formulations. This underscores the necessity for alternative methods, such as in vitro permeation tests (IVPT) and physiologically based pharmacokinetic (PBPK) modelling, to better understand the dermal pharmacokinetics of a product. The purpose of this study was to modify, verify, and validate the PBPK model of caffeine permeation through human skin previously developed by Patel et al. (2022), and compare simulation results with experimental data from IVPT studies. Moreover, the study aimed to analyse the IVPT data variability and explore the potential of using the PBPK model to understand the influence of biological and drug-related factors on the IVPT results. In total, eight manuscripts describing nine experiments were included. The overall shapes of the permeation curves were considered acceptable based on visual checks for all analysed experiments. Five out of nine experiments met the predefined standard 2-fold difference criterion for comparison of the cumulative amount of caffeine in the receptor solution.. Our investigation highlights challenges in validating PBPK models for IVPT experiments, as the quality and consistency of experimental results pose significant hurdles. Despite access to data on caffeine permeation in scientific literature, reliable model validation is currently infeasible. Inter-laboratory variation suggests that alternative validation methods may be needed. Further studies should focus on issues with other compounds, especially lipophilic ones.

Formulation and evaluation of carrier-based dry powders containing budesonide and arformoterol for inhalation therapy

ABSTRACT Asthma and Chronic Obstructive Pulmonary Disease (COPD) are major global health issues, with inhalation therapy being a primary treatment method. However, dry powder inhalers (DPIs) often face the issue of drug particle aggregation, which can reduce drug delivery efficiency. This study aims to investigate particle aggregation and optimize the cohesion–adhesion balance to improve inhalation efficiency. Advanced techniques such as atomic force microscopy and Raman imaging were employed to analyze particle interactions and aggregation behavior, focusing on lactose ratios, particle shapes, and drug-drug interactions. The therapeutic efficacy of optimized formulations containing Budesonide (BUD) and Arformoterol (AFT) was evaluated in an asthma model. Specifically, sRAW, neutrophil count, and tidal volume values were significantly improved compared to the positive control group, with p-values below 0.01. AFT demonstrated equivalent efficacy to Formoterol at half the dose. Additionally, pharmacokinetic (PK) studies showed that both drugs exhibited similar in vivo behavior, confirming the therapeutic superiority of AFT. (p-value for AUC0-t and Cmax: 0.646 and 0.153, respectively) The key findings highlight that formulation optimization significantly reduces particle aggregation and improves drug delivery efficiency in DPI (FPF for AFT and BUD: 39.4% and 50.6%, respectively), suggesting the potential for enhanced clinical outcomes in asthma and COPD patients. This study provides valuable insights for the formulation development of inhalable therapies.

Synthesis, biological evaluation, molecular docking analyses, and ADMET study of azo derivatives containing 1-naphthol against MβL-producing S. maltophilia

Stenotrophomonas maltophilia is a model organism exhibiting intrinsic antibiotic resistance, primarily due to its production of Mβ-lactamase enzymes that inactivate β-lactam antibiotics. This study aims to synthesize an azo derivative containing an oxazepine ring as a potential inhibitor of Mβ-lactamase. The molecular docking results revealed that the binding energies of the Mβ-lactamases ranged from − 5.95 to − 6.09 kcal/mol, indicating favourable interactions with the synthesized compounds. Two compounds were prepared: the first via aldol condensation of (A1) with p-hydroxybenzaldehyde to form (K1) and the second through Azo-Schiff base formation from 3,5-dimethylaniline, resulting in (L2) and (L18). Characterization of these compounds was conducted via FT-IR, CHN, 1H NMR, and 13C NMR spectroscopy. Antimicrobial activity was assessed through minimum inhibitory concentration (MIC) and minimum bacterial concentration (MBC) tests, which yielded values ranging from 1.19 ± 1 to 0.02 µg/mL and from 1.12 ± 1 to > 0.04 µg/mL, respectively. Notably, the MBC/MIC ratios indicated that L2 and L18 exhibited significant bactericidal activity. In silico analysis via MOE 2015 software allowed us to determine the binding poses and energies of the synthesized inhibitors against Mβ-lactamase (PDB ID: 6UAF). The most stable conformation from the docking results was selected for further evaluation. Compared with standard ceftazidime, the synthesized compounds significantly inhibited Mβ-lactamase activity. Additionally, ADMET analysis indicated favourable pharmacokinetic profiles and low toxicity, suggesting promising oral drug-like properties for the synthesized molecules.

A comparison of branched DNA and reverse transcriptase quantitative polymerase chain reaction methodologies for quantitation of lipid nanoparticle encapsulated mRNA.

Messenger RNA (mRNA)-based therapeutics have emerged as a promising modality for various clinical applications, necessitating robust methods for mRNA quantification. This biodistribution study compares the performance of branched DNA and reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) assays for measuring lipid nanoparticle-encapsulated mRNA. Following intravenous administration of nascent peptide imaging luciferase mRNA (1mg/kg) to rats, mRNA levels in various tissues and serum were quantified using both assays. Statistical analyses, including Bland-Altman, Deming regression and Passing-Bablok regression, were employed to assess method comparability and reproducibility. The results indicated that mRNA pharmacokinetics measured by branched DNA and RT-qPCR were largely consistent across tissues, with RT-qPCR showing greater reproducibility across multiple laboratories. RT-qPCR also demonstrated a wider dynamic range and higher sensitivity, making it a more versatile option for large-scale studies. Despite some differences in data due to tissue types and timepoints, both methods provided comparable pharmacokinetic profiles for mRNA quantification. This study underscores the importance of selecting an appropriate quantification method based on study requirements and highlights RT-qPCR's adaptability for multisite research, especially for the clinical development of mRNA-based therapeutics.

Comparative Preclinical Pharmacokinetics and Disposition of Favipiravir Following Pulmonary and Oral Administration as Potential Adjunct Therapy Against Airborne RNA Viruses.

Favipiravir is administered orally, even against airborne RNA viruses, in a loading-dose/maintenance dose regimen. We investigated whether-(a) pulmonary delivery of favipiravir would generate high concentrations in the luminal side of the respiratory tract; and (b) avoiding first-pass metabolism by the liver by inhaled drug would generate comparable pharmacokinetics (PK) with doses significantly smaller than the oral maintenance dose. A dry powder inhalation (DPI) of favipiravir formulated by mixing with Inhalac 400® was prepared and characterized. Inhalations of ~ 120µg dose strength, with or without a prior oral loading dose were administered to mice. Comparator mice received human-equivalent oral doses (3mg). Three mice per sampling time point were sacrificed and favipiravir concentrations in the blood plasma, bronchio-alveolar lavage fluid (BALF) and lung tissue homogenate determined by HPLC. One-compartment PK modeling of concentration-time data indicated that the area under the curve (AUC0-24h) generated in the BALF recovered from mice receiving inhalations of ~ 1/25th of the oral dose subsequent to an oral loading dose was 86.72 ± 4.48µg⋅mL-1⋅h. This was consistently higher than the AUC observed in the BALF of orally-dosed mice (56.71 ± 53.89µgmL-1⋅h). In blood serum, the respective values of AUC were 321.55 ± 124.91 and 354.71 ± 99.60µg⋅mL-1⋅h. Pulmonary delivery of significantly smaller doses of favipiravir generates meaningful drug disposition and pharmacokinetics at the site of respiratory viral infections. We provide the rationale for designing a self-administered, non-invasive, low-cost, targeted drug delivery system against airborne RNA virus infection.

Exome Sequence Data of Eight SLC Transporters Reveal That SLC22A1 and SLC22A3 Variants Alter Metformin Pharmacokinetics and Glycemic Control.

Background: Type 2 diabetes (T2D) is one of the leading causes of mortality and is a public health challenge worldwide. Metformin is the first-choice treatment for T2D; its pharmacokinetics (PK) is facilitated by members of the solute carrier (SLC) superfamily of transporters, it is not metabolized, and it is excreted by the kidney. Although interindividual variability in metformin pharmacokinetics is documented in the Mexican population, its pharmacogenomics is still underexplored. We aimed to identify variants in metformin SLC transporter genes associated with metformin PK and response in Mexican patients. Methods: Using exome data from 2217 Mexican adults, we identified 86 biallelic SNVs in the eight known genes encoding SLC transporters, with a minor allele frequency ≥ 1%, which were analyzed in an inadequate glycemic control (IGC) association study in T2D metformin treated patients. Metformin PK was evaluated in a pediatric cohort and the effect of associated SNVs was correlated. Results: Functional annotation classified two SNVs as pathogenic. The association study revealed two blocks associated with IGC. These haplotypes comprise rs622591, rs4646272, rs4646273, and rs4646276 in SLC22A1; and rs1810126 and rs668871 in SLC22A3. PK profiles revealed that homozygotes of the SLC22A1 haplotype reached lower plasma metformin concentrations 2 h post administration than the other groups. Conclusions: Our findings highlight the potential of pharmacogenomics studies to enhance precision medicine, which may involve dosage adjustments or the exploration of alternative therapeutic options. These hold significant implications for public health, particularly in populations with a high susceptibility to develop metabolic diseases, such as Latin Americans.

Bioequivalence Analysis of Clindamycin Hydrochloride Capsules in Healthy Chinese Subjects Under Fasted and Fed Conditions.

Clindamycin is a lincosamide antibiotic for the treatment of staphylococcal, streptococcal, and anaerobic bacterial infections. We conducted a single-center, single-dose, 2-preparation, 2-period, 2-sequence, randomized, open-label, 2×2 crossover study to evaluate the pharmacokinetics (PKs) and safety of the test and reference clindamycin hydrochloride capsules in healthy Chinese subjects under both fasted and fed conditions. Forty-eight subjects were enrolled in the study totally, with 24 subjects in each group. All subjects were asked to take a test or reference preparation, under either fasted or fed condition, and their blood samples were collected and assayed by a validated high-performance liquid chromatography-tandem mass spectrometry method. PK parameters including maximum plasma concentration, area under the plasma concentration-time curve from time 0 to the last concentration, and area under the plasma concentration-time curve from time 0 to infinity were estimated with noncompartmental model and analyzed. Results showed that the PK profiles of the 2 preparations were consistent and met the bioequivalence criteria. Food was identified as a factor that had an impact on clindamycin absorption. The safety of clindamycin hydrochloride capsules was satisfactory. This study proved that the 2 clindamycin hydrochloride capsules were bioequivalent in healthy Chinese subjects under both fasted and fed conditions.