Characterization of ascending dose canine telemetry model supports its use in E14/S7B QT integrated risk assessments.

INTRODUCTION: Nonclinical evaluation of the cardiovascular effects of novel chemical or biological entities (NCE, NBEs) is crucial for supporting first-in-human clinical trials. One important aspect of these evaluations is the assessment of potential QT/QTc prolongation risk, as drug-induced QT prolongation can have catastrophic effects. The recent publication of E14/S7B Q&As allows for the situational incorporation of nonclinical QTc data as part of an integrated risk assessment for a Thorough QT (TQT) waiver application provided certain best practice criteria are met. Recent publications provided detailed characterization of nonclinical QTc telemetry data collected from the commonly used Latin square study design. METHODS: To understand whether data from alternate telemetry study designs were sufficient to serve as part of the E14/S7B integrated risk assessment, we report the performance and translational sensitivity to identify clinical risk of QTc prolongation risk for an ascending dose telemetry design. RESULTS: The data demonstrated low variability in QTci interval within animals from day to day, indicating a well-controlled study environment and limited concern for uncontrolled effects across dosing days. Historical study variances of the ascending dose design with n = 4 subjects, measured by least significant difference (LSD) and root mean square error (RMSE) values, were low enough to detect a + 10 ms QTci interval change, and the median minimum detectable difference (MDD) for QTci interval changes was <10 ms. Furthermore, concentration-QTci (C-QTci) assessments to determine +10 ms QTci increases for known hERG inhibitors were comparable to clinical CC values listed in the E14/S7B training materials, supporting the use of the ascending dose design in an E14/S7B integrated risk assessment. DISCUSSION: These findings suggest that the ascending dose design can be a valuable tool in nonclinical evaluation of QT/QTc prolongation risk and the support of TQT waiver applications.

Efficacy of omadacycline in the treatment of Legionella pneumonia: a case report.

Legionella, one of the main pathogens that causes community-acquired pneumonia, can lead to Legionella pneumonia, a condition characterized predominantly by severe pneumonia. This disease, caused by the bacterium Legionella pneumophila, can quickly progress to critical pneumonia and is often associated with damage to multiple organs. As a result, it requires close attention in terms of clinical diagnosis and treatment. Omadacycline, a new type of tetracycline derivative belonging to the aminomethylcycline class of antibiotics, is a semi-synthetic compound derived from minocycline. Its key structural feature, the aminomethyl modification, allows omadacycline to overcome bacterial resistance and broadens its range of effectiveness against bacteria. Clinical studies have demonstrated that omadacycline is not metabolized in the body, and patients with hepatic and renal dysfunction do not need to adjust their dosage. This paper reports a case of successful treatment of Legionella pneumonia with omadacycline in a patient who initially did not respond to empirical treatment with moxifloxacin. The patient also experienced electrolyte disturbance, as well as dysfunction in the liver and kidneys, delirium, and other related psychiatric symptoms.

Impact of Airborne Exposure to PM10 Increases Susceptibility to P. aeruginosa Infection.

The effects of exposure to airborne particulate matter with a size of 10 µm or less (PM10) on C57BL/6 mouse corneas, their response to Pseudomonas aeruginosa (PA) infection, and the protective effects of SKQ1 were determined. C57BL/6 mouse corneas receiving PBS or SKQ1 were exposed to control (air) or PM10 for 2 weeks, infected, and the disease was documented by clinical score, PMN quantitation, bacterial plate count, RT-PCR and Western blot. PBS-treated, PM10-exposed corneas did not differ at 1 day postinfection (dpi), but exhibited earlier (3 dpi) corneal thinning compared to controls. By 3 dpi, PM10 significantly increased corneal mRNA levels of several pro-inflammatory cytokines, but decreased IL-10, NQO1, GR1, GPX4, and Nrf2 over control. SKQ1 reversed these effects and Western blot selectively confirmed the RT-PCR results. PM10 resulted in higher viable bacterial plate counts at 1 and 3 dpi, but SKQ1 reduced them at 3 dpi. PM10 significantly increased MPO in the cornea at 3 dpi and was reduced by SKQ1. SKQ1, used as an adjunctive treatment to moxifloxacin, was not significantly different from moxifloxacin alone. Exposure to PM10 increased the susceptibility of C57BL/6 to PA infection; SKQ1 significantly reversed these effects, but was not effective as an adjunctive treatment.

Determination of levofloxacin, norfloxacin, and moxifloxacin in pharmaceutical dosage form or individually using derivative UV spectrophotometry.

PURPOSE: In this study, first, second, third, and fourth-order derivative spectrophotometric methods utilizing the peak-zero (P-O) and peak-peak (P-P) techniques of measurement were developed for the determination of levofloxacin, norfloxacin, and moxifloxacin. These methods were applied to their combined pharmaceutical dosage form or individually for levofloxacin, norfloxacin, and moxifloxacin. METHODS: Linearity was established in the concentration range of 2-20 µg/mL. The procedures are simple, quick, and precise. The developed methods are sensitive, accurate, and cost-effective, demonstrating excellent correlation coefficients (R2 = 0.9998) and mean recovery values ranging from 99.20% to 100.08%, indicating a high level of precision. RESULTS: The developed approach was effectively employed to determine the levofloxacin, norfloxacin, and moxifloxacin content in commercially available pharmaceutical dosages. CONCLUSIONS: Statistical analysis and recovery tests confirmed the method's linearity and accuracy. The results suggest that this method can be utilized for routine analysis in both bulk and commercial formulations. The simplicity, accuracy, and cost-effectiveness of the developed methods make them valuable for pharmaceutical analysis.

Dual Drug-Loaded Coaxial Nanofiber Dressings for the Treatment of Diabetic Foot Ulcer.

Introduction: Diabetes mellitus is frequently associated with foot ulcers, which pose significant health risks and complications. Impaired wound healing in diabetic patients is attributed to multiple factors, including hyperglycemia, neuropathy, chronic inflammation, oxidative damage, and decreased vascularization. Rationale: To address these challenges, this project aims to develop bioactive, fast-dissolving nanofiber dressings composed of polyvinylpyrrolidone loaded with a combination of an antibiotic (moxifloxacin or fusidic acid) and anti-inflammatory drug (pirfenidone) using electrospinning technique to prevent the bacterial growth, reduce inflammation, and expedite wound healing in diabetic wounds. Results: The fabricated drug-loaded fibers exhibited diameters of 443 ± 67 nm for moxifloxacin/pirfenidone nanofibers and 488 ± 92 nm for fusidic acid/pirfenidone nanofibers. The encapsulation efficiency, drug loading and drug release studies for the moxifloxacin/pirfenidone nanofibers were found to be 70 ± 3% and 20 ± 1 µg/mg, respectively, for moxifloxacin, and 96 ± 6% and 28 ± 2 µg/mg, respectively, for pirfenidone, with a complete release of both drugs within 24 hours, whereas the fusidic acid/pirfenidone nanofibers were found to be 95 ± 6% and 28 ± 2 µg/mg, respectively, for fusidic acid and 102 ± 5% and 30 ± 2 µg/mg, respectively, for pirfenidone, with a release rate of 66% for fusidic acid and 80%, for pirfenidone after 24 hours. The efficacy of the prepared nanofiber formulations in accelerating wound healing was evaluated using an induced diabetic rat model. All tested formulations showed an earlier complete closure of the wound compared to the controls, which was also supported by the histopathological assessment. Notably, the combination of fusidic acid and pirfenidone nanofibers demonstrated wound healing acceleration on day 8, earlier than all tested groups. Conclusion: These findings highlight the potential of the drug-loaded nanofibrous system as a promising medicated wound dressing for diabetic foot applications.

Optimized J to T peak and T peak to T end measurements in nonclinical species administered moxifloxacin and amiodarone.

INTRODUCTION: Cardiovascular safety and the risk of developing the potentially fatal ventricular tachyarrhythmia, Torsades de Pointes (TdP), have long been major concerns of drug development. TdP is associated with a delayed ventricular repolarization represented by QT interval prolongation in the electrocardiogram (ECG), typically due to block of the potassium channel encoded by the human ether-a-go-go related gene (hERG). Importantly however, not all drugs that prolong the QT interval are torsadagenic and not all hERG blockers prolong the QT interval. Recent clinical reports suggest that partitioning the QT interval into early (J to T peak; JTp) and late repolarization (T peak to T end; TpTe) components may be valuable for distinguishing low-risk mixed ion channel blockers (hERG plus calcium and/or late sodium currents) from high-risk pure hERG channel blockers. This strategy, if true for nonclinical animal models, could be used to de-risk QT prolonging compounds earlier in the drug development process. METHODS: To explore this, we investigated JTp and TpTe in ECG data collected from telemetered dogs and/or monkeys administered moxifloxacin or amiodarone at doses targeting relevant clinical exposures. An optimized placement of the Tpeak fiducial mark was utilized, and all intervals were corrected for heart rate (QTc, JTpc, TpTec). RESULTS: Increases in QTc and JTpc intervals with administration of the pure hERG blocker moxifloxacin and an initial QTc and JTpc shortening followed by prolongation with the mixed ion channel blocker amiodarone were detected as expected, aligning with clinical data. However, anticipated increases in TpTec by both standard agents were not detected. DISCUSSION: The inability to detect changes in TpTec reduces the utility of these subintervals for prediction of arrhythmias using continuous single­lead ECGs collected from freely moving dogs and monkeys.

Optimization of graphene polypyrrole for enhanced adsorption of moxifloxacin antibiotic: an experimental design approach and isotherm investigation.

The presence of antibiotics in water systems had raised a concern about their potential harm to the aquatic environment and human health as well as the possible development of antibiotic resistance. Herein, this study investigates the power of adsorption using graphene-polypyrrole (GRP-PPY) nanoparticles as a promising approach for the removal of Moxifloxacin HCl (MXF) as a model antibiotic drug. GRP-PPY nanoparticles synthesis was performed with a simple and profitable method, leading to the formation of high surface area particles with excellent adsorption properties. Characterization was assessed with various techniques, including Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD) and Brunauer-Emmett-Teller (BET). Box-Behnken experimental design was developed to optimize the adsorption process. Critical parameters such as initial antibiotic concentration, nanoparticle concentration, and pH were investigated. The Freundlich isotherm model provided a good fit to the experimental data, indicating multilayer adsorption of MXF onto the GRP-PPY-NP. As a result, a high adsorption capacity of MXF (92%) was obtained in an optimum condition of preparing 30 µg/mL of the drug to be adsorbed by 1 mg/mL of GRP-PPY-NP in pH 9 within 1 h in a room temperature. Moreover, the regeneration and reusability of GRP-PPY-NP were investigated. They could be effectively regenerated for 3 cycles using appropriate desorption agents without significant loss in adsorption capacity. Overall, this study highlights the power of GRP-PPY-NP as a highly efficient adsorbent for the removal of MXF from wastewater as it is the first time to use this NP for a pharmaceutical product which shows the study's novelty, and the findings provide valuable insights into the development of sustainable and effective wastewater treatment technologies for combating antibiotic contamination in aquatic environments.

Moxifloxacin promotes two-photon microscopic imaging for discriminating different stages of DSS-induced colitis on mice.

BACKGROUND: Accurate diagnosis of patients with ulcerative colitis (UC) can reduce their risk of developing colorectal cancer. This study intended to explore whether moxifloxacin, an agent with fluorescence potential, could promote two-photon microscopy (TPM) diagnosis for mice with dextran sodium sulfate (DSS)-induced colitis, which could imitate human UC. METHODS: 32 Balb/c mice were randomly divided into 4 groups: control, acute colitis, remission colitis and chronic colitis. Fluorescence parameters, imaging performance, and tissue features of different mouse models were compared under moxifloxacin-assisted TPM and label-free TPM. RESULTS: Excitation wavelength of 720 nm and moxifloxacin labeling time of 2 min was optimal for moxifloxacin-assisted TPM. With moxifloxacin labeling for colonic tissues, excitation power was decreased to 1/10 of that without labeling while fluorescence intensity was increased to 10-fold of that without labeling. Photobleaching was negligible after moxifloxacin labeling and moxifloxacin fluorescence kept stable within 2 h. Compared with the control group, moxifloxacin fluorescence was reduced in the three colitis groups (P < 0.05). Meanwhile, the proportion of enhanced moxifloxacin fluorescence regions was (22.4 ± 1.6)%, (7.7 ± 1.0)%, (13.5 ± 1.7)% and (5.0 ± 1.3)% in the control, acute, remission and chronic groups respectively, with significant reduction in the three colitis groups (P < 0.05). Besides, variant tissue features of experimental colitis models were presented under moxifloxacin-assisted TPM, such as crypt opening, glandular structure, adjacent glandular space and moxifloxacin distribution. CONCLUSIONS: With unique biological interaction between moxifloxacin and colonic mucosa, moxifloxacin-assisted TPM imaging is feasible and effective for accurate diagnosis of different stages of experimental colitis.

Comparative evaluation of intensified short course regimen and standard regimen for adults TB meningitis: a protocol for an open label, multi-center, parallel arms, randomized controlled superiority trial (INSHORT trial).

BACKGROUND: Despite several incremental improvements in the management of tuberculous meningitis (TBM), the mortality rates remain high. In spite of national and international guidelines, variation in the choice, dose, and duration of drugs exist between countries and clinicians. We propose to evaluate a shorter and more effective regimen containing agents with augmented intracerebral drug exposure and anti-inflammatory approaches to improve disability-free survival among patients with TBM. Our strategy incorporates the various developments in the field of TBM over the last two decades and only few trials have evaluated a composite of these strategies in the overall outcomes of TBM. METHODS: An open label, parallel arms, randomized controlled superiority trial will be conducted among 372 participants across 6 sites in India. Eligible participants will be randomly allocated in 1:1:1 ratio into one of the three arms. The intervention arm consists of 2 months of high-dose rifampicin (25 mg/kg), moxifloxacin (400 mg), pyrazinamide, isoniazid, aspirin (150 mg), and steroids followed by rifampicin, isoniazid, and pyrazinamide for 4 months. The second intervention arm includes all the drugs as per the first arm except aspirin and the patients in the control arm will receive treatment according to the National TB Elimination Program guidelines. All participants will be followed up for 1 year after the treatment.  DISCUSSION: Current WHO regimens have agents with poor central nervous system drug exposure and is too long. It does not reflect the accumulating evidence in the field. We propose a comprehensive clinical trial incorporating the emerging evidence accrued over the last two decades to shorten the duration and improve the treatment outcomes. This multi-centric trial may generate crucial evidence with policy and practice implications in the treatment of TBM. TRIAL REGISTRATION: Clinical Trial Registry India CTRI/2023/05/053314. Registered on 31 May 2023 ( https://ctri.nic.in/Clinicaltrials/pmaindet2.php?EncHid=ODYzMzg=&Enc=&userName=CTRI/2023/05/053314 ). CLINICALTRIALS: gov NCT05917340. Registered on 6 August 2023 ( https://classic. CLINICALTRIALS: gov/ct2/show/NCT05917340 ). PROTOCOL VERSION: Version 1.3 dated 12 July 2023.

Nanocrystalline cellulose as a reinforcing agent for poly (vinyl alcohol)/ gellan-gum-based composite film for moxifloxacin ocular delivery.

Nanocrystalline cellulose (NCC) is a star material in drug delivery applications due to its good biocompatibility, large specific surface area, high tensile strength (TS), and high hydrophilicity. Poly(Vinyl Alcohol)/Gellan-gum-based innovative composite film has been prepared using nanocrystalline cellulose (PVA/GG/NCC) as a strengthening agent for ocular delivery of moxifloxacin (MOX) via solvent casting method. Impedance analysis was studied using the capacitive sensing technique for examining new capacitance nature of the nanocomposite MOX film. Antimicrobial properties of films were evaluated using Pseudomonas aeruginosa and Staphylococcus aureus as gram-negative and gram-positive bacteria respectively by disc diffusion technique. XRD revealed the characteristic peak of NCC and the amorphous form of the drug. Sustained in vitro release and enhanced corneal permeation of drug were noticed in the presence of NCC. Polymer matrix enhanced the mechanical properties (tensile strength 22.05 to 28.41 MPa) and impedance behavior (resistance 59.23 to 213.23 Ω) in the film due to the presence of NCC rather than its absence (16.78 MPa and 39.03 Ω respectively). Occurrence of NCC brought about good antimicrobial behavior (both gram-positive and gram-negative) of the film. NCC incorporated poly(vinyl alcohol)/gellan-gum-based composite film exhibited increased mechanical properties and impedance behavior for improved ocular delivery of moxifloxacin.

Evaluation of critical parameters in the hollow-fibre system for tuberculosis: A case study of moxifloxacin.

AIMS: The hollow­fibre system for tuberculosis (HFS­TB) is a preclinical model qualified by the European Medicines Agency to underpin the anti­TB drug development process. It can mimic in vivo pharmacokinetic (PK)­pharmacodynamic (PD) attributes of selected antimicrobials, which could feed into in silico models to inform the design of clinical trials. However, historical data and published protocols are insufficient and omit key information to allow experiments to be reproducible. Therefore, in this work, we aim to optimize and standardize various HFS­TB operational procedures. METHODS: First, we characterized bacterial growth dynamics with different types of hollow­fibre cartridges, Mycobacterium tuberculosis strains and media. Second, we mimicked a moxifloxacin PK profile within hollow­fibre cartridges, in order to check drug­fibres compatibility. Lastly, we mimicked the moxifloxacin total plasma PK profile in human after once daily oral dose of 400 mg to assess PK­PD after different sampling methods, strains, cartridge size and bacterial adaptation periods before drug infusion into the system. RESULTS: We found that final bacterial load inside the HFS­TB was contingent on the studied variables. Besides, we demonstrated that drug­fibres compatibility tests are critical preliminary HFS­TB assays, which need to be properly reported. Lastly, we uncovered that the sampling method and bacterial adaptation period before drug infusion significantly impact actual experimental conclusions. CONCLUSION: Our data contribute to the necessary standardization of HFS­TB experiments, draw attention to multiple aspects of this preclinical model that should be considered when reporting novel results and warn about critical parameters in the HFS­TB currently overlooked.

Successful maintenance treatment of disseminated nocardiosis with cerebral abscess in a severely immunocompromised patient allergic to trimethoprim-sulfamethoxazole using moxifloxacin and high-dose minocycline: A case report.

Nocardiosis in patients after allogeneic hematopoietic stem cell transplantation (HSCT) is rare, but is associated with a significant mortality risk. Although trimethoprim-sulfamethoxazole (TMP/SMX) remains the cornerstone of nocardiosis treatment, optimal alternative therapies for patients intolerant to TMP/SMX are not well-established. Herein, we report a case of disseminated nocardiosis with bacteremia and multiple lesions in the lungs and brain caused by Nocardia farcinica, in a 60-year-old man who had previously undergone allogeneic HSCT and was receiving immunosuppressants for severe chronic graft-versus-host disease. The patient received atovaquone for the prophylaxis of Pneumocystis pneumonia because of a previous serious allergic reaction to TMP/SMX. The patient was initially treated with imipenem/cilastatin and amikacin, which were later switched to ceftriaxone and amikacin based on the results of antimicrobial susceptibility testing. After switching to oral levofloxacin and a standard dose of minocycline, the patient experienced a single recurrence of brain abscesses. However, after switching to oral moxifloxacin and high-dose minocycline, the patient did not experience any relapses during the subsequent two years and seven months of treatment. In treating nocardiosis with brain abscesses, it is crucial to select oral antibiotics based on the antimicrobial susceptibility test results and pharmacokinetics, especially when TMP/SMX is contraindicated. A combination of oral moxifloxacin and high-dose minocycline could be a promising alternative therapy.

Topical Antibiotic Therapy in the Ocular Environment: The Benefits of Using Moxifloxacin Eyedrops.

Moxifloxacin is a fourth-generation fluoroquinolone antibiotic available for ophthalmic use. It inhibits two enzymes involved in bacterial DNA synthesis, covering Gram-positive and Gram-negative pathogens. This spectrum allows for the formulation of self-preserving bottle solutions, while its interesting pharmacological profile is distinguished by efficacy at low tissue concentrations and by an infrequent dose regimen due to its long duration on ocular tissues. This enhances patient compliance, promoting its use in children. The human eye hosts several microorganisms; this collection is called the ocular microbiota, which protects the ocular surface, assuring homeostasis. When choosing an antibiotic, it is appropriate to consider its influence on microbiota. A short dose regimen is preferred to minimize the impact of the drug. Moxifloxacin eyedrops represent an effective and safe tool to manage and prevent ocular infections. As healthcare providers face the complexity of the ocular microbiota and microbial resistance daily, the informed use of moxifloxacin is necessary to preserve its efficacy in the future. In this regard, it is well known that moxifloxacin has a lower capacity to induce resistance (an optimal WPC and MPC) compared to other quinolones, but much still needs to be explored regarding the impact that fluoroquinolones could have on the ocular microbiota.

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The patient, a male newborn, was admitted to the hospital 2 hours after birth due to prematurity (gestational age 27+5 weeks) and respiratory distress occurring 2 hours postnatally. After admission, the infant developed fever and elevated C-reactive protein levels. On the fourth day after birth, metagenomic next-generation sequencing of cerebrospinal fluid indicated a positive result for Mycoplasma hominis (9 898 reads). On the eighth day, a retest of cerebrospinal fluid metagenomics confirmed Mycoplasma hominis (56 806 reads). The diagnosis of purulent meningitis caused by Mycoplasma hominis was established, and the antibiotic treatment was switched to moxifloxacin [5 mg/(kg·day)] administered intravenously for a total of 4 weeks. After treatment, the patient's cerebrospinal fluid tests returned to normal, and he was discharged as cured on the 76th day after birth. This article focuses on the diagnosis and treatment of neonatal Mycoplasma hominis purulent meningitis, introducing the multidisciplinary diagnosis and treatment of the condition in extremely preterm infants.

Differences in nature killer cell response and interference with mitochondrial DNA induced apoptosis in moxifloxacin environment.

OBJECTIVES: As antibiotics become more prevalent, accuracy and safety are critical. Moxifloxacin (MXF) have been reported to have immunomodulatory effects on a variety of immune cells and even anti-proliferative and pro-apoptotic effects, but the mechanism of action is not fully clear. METHODS: Peripheral blood mononuclear cells (PBMC) from experimental groups of healthy adults (n = 3) were treated with MXF (10ug/ml) in vitro for 24 h. Single-cell sequencing was performed to investigate differences in the response of each immune cell to MXF. Flow cytometry determined differential gene expression in subsets of most damaged NK cells. Pseudo-time analysis identified drivers that influence MXF-stimulated cell differentiation. Detection of mitochondrial DNA and its involvement in the mitochondrial respiratory chain pathway clarifies the origin of MXF-induced stress injury. RESULTS: Moxifloxacin-environmental NK cells are markedly reduced: a new subset of NK cells emerges, and immediate-early-response genes in this subset indicate the presence of an early activation response. The inhibitory receptor-dominant subset shows enhanced activation, leading to increased expression of cytokines and chemokines. The near-mature subset showed greater cytotoxicity and the most pronounced cellular damage. CD56bright cells responded by antagonizing the regulation of activation and inhibitory signals, demonstrating a strong cleavage capacity. The severe depletion of mitochondrial genes was focused on apoptosis induced by the mitochondrial respiratory chain complex. CONCLUSION: NK cells exhibit heightened sensitivity to the MXF environment. Different NK subsets upregulate the expression of cytokines and chemokines through different activation pathways. Concurrently, MXF induces impairment of the mitochondrial oxidative phosphorylation system, culminating in apoptosis.

Azithromycin and moxifloxacin resistance determinants in Mycoplasma genitalium in Lleida, Spain.

OBJECTIVE: Mycoplasma genitalium (MG) is a microorganism related to sexually transmitted infections. Antibiotic resistance of MG leads to an increase in treatment failure rates and the persistence of the infection. The aim of this study was to describe the most frequent mutations associated with azithromycin and moxifloxacin resistance in our geographical area. METHODS: A prospective study from May 2019 to May 2023 was performed. MG-positive samples were collected. Real-time PCRs (AllplexTM MG-AziR Assay and AllplexTM MG-MoxiR Assay, Seegene) were performed in MG positive samples to detect mutations in 23S rRNA V domain and parC gene. RESULTS: A 37.1% of samples presented resistance determinants to azithromycin and the most common mutation detected was A2059G (57.9%). Resistance to moxifloxacin was studied in 72 azithromycin-resistant samples and 36.1% showed mutations, being G248T the most prevalent (73.1%). CONCLUSIONS: The resistance to different lines of treat ment suggests the need for a targeted therapy and the performing of a test of cure afterwards.

Triple combination dry powder formulation of pretomanid, moxifloxacin, and pyrazinamide for treatment of multidrug-resistant tuberculosis.

Both latent and multidrug-resistant tuberculosis (TB) have been causing significant concern worldwide. A novel drug, pretomanid (PA-824), has shown a potent bactericidal effect against both active and latent forms of Mycobacterium tuberculosis (MTb) and a synergistic effect when combined with pyrazinamide and moxifloxacin. This study aimed to develop triple combination spray dried inhalable formulations composed of antitubercular drugs, pretomanid, moxifloxacin, and pyrazinamide (1:2:8 w/w/w), alone (PaMP) and in combination with an aerosolization enhancer, L-leucine (20 % w/w, PaMPL). The formulation PaMPL consisted of hollow, spherical, dimpled particles (<5 µm) and showed good aerosolization behaviour with a fine particle fraction of 70 %. Solid-state characterization of formulations with and without L-leucine confirmed the amorphous nature of moxifloxacin and pretomanid and the crystalline nature of pyrazinamide with polymorphic transformation after the spray drying process. Further, the X-ray photoelectron spectroscopic analysis revealed the predominant surface composition of L-leucine on PaMPL dry powder particles. The dose-response cytotoxicity results showed pyrazinamide and moxifloxacin were non-toxic in both A549 and Calu-3 cell lines up to 150 µg/mL. However, the cell viability gradually decreased to 50 % when the pretomanid concentration increased to 150 µg/mL. The in vitro efficacy studies demonstrated that the triple combination formulation had more prominent antibacterial activity with a minimum inhibitory concentration (MIC) of 1 µg/mL against the MTb H37Rv strain as compared to individual drugs. In conclusion, the triple combination of pretomanid, moxifloxacin, and pyrazinamide as an inhalable dry powder formulation will potentially improve treatment efficacy with fewer systemic side effects in patients suffering from latent and multidrug-resistant TB.

Bacteria-Targeting Nanoparticles with ROS-Responsive Antibiotic Release to Eradicate Biofilms and Drug-Resistant Bacteria in Endophthalmitis.

Background: Bacterial endophthalmitis is an acute progressive visual threatening disease and one of the most important causes of blindness worldwide. Current treatments are unsatisfactory due to the emergence of drug-resistant bacteria and the formation of biofilm. Purpose: The aim of our research was to construct a novel nano-delivery system with better antimicrobial and antibiofilm effects. Methods: This study developed a novel antibiotic nanoparticle delivery system (MXF@UiO-UBI-PEGTK), which is composed of (i) moxifloxacin (MXF)-loaded UiO-66 nanoparticle as the core, (ii) bacteria-targeting peptide ubiquicidin (UBI29-41) immobilized on UiO-66, and (iii) ROS-responsive poly (ethylene glycol)-thioketal (PEG-TK) as the surface shell. Then the important properties of the newly developed delivery system, including biocompatibility, toxicity, release percentage, thermal stability, ability of targeting bacteria, and synergistic antibacterial effects on bacterial biofilms and endophthalmitis, were evaluated. Results: In vitro, MXF@UiO-UBI-PEGTK exhibited significant antibiotic effects including the excellent antibiofilm property against Staphylococcus aureus, Pseudomonas aeruginosa, and methicillin-resistant Staphylococcus aureus at high levels of ROS. Moreover, MXF@UiO-UBI-PEGTK demonstrated outstanding efficacy in treating bacterial endophthalmitis in vivo. Conclusion: This novel nanoparticle delivery system with ROS-responsive and bacteria-targeted properties promotes the precise and effective release of drugs and has significant potential for clinical application of treating bacterial endophthalmitis.