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Islatravir is a deoxynucleoside analog being developed for the treatment of HIV-1 infection. Clinical studies are being conducted to evaluate islatravir, administered in combination with other antiretroviral therapies, at doses of 0.25 mg once daily and 2 mg once weekly. In multiple previous clinical studies, islatravir was generally well tolerated, with no clear trend in cardiac adverse events. A trial was conducted to evaluate the effect of islatravir on cardiac repolarization. A randomized, double-blind, active- and placebo-controlled phase 1 trial was conducted, in which a single dose of islatravir 0.75 mg, islatravir 240 mg (supratherapeutic dose), moxifloxacin 400 mg (active control), or placebo was administered. Continuous 12-lead electrocardiogram monitoring was performed before dosing through 24 hours after dosing. QT interval measurements were collected, and safety and pharmacokinetics were evaluated. Sixty-three participants were enrolled, and 59 completed the study. Fridericia's QT correction for heart rate was inadequate; therefore, a population-specific correction was applied (QTcP). The placebo-corrected change from baseline in QTcP (ΔΔQTcP) interval at the observed geometric mean maximum plasma concentration associated with islatravir 0.75 mg and islatravir 240 mg was <10 ms at all time points. Assay sensitivity was confirmed because the use of moxifloxacin 400 mg led to a ΔΔQTcP >10 ms. The pharmacokinetic profile of islatravir was consistent with that of previous studies, and islatravir was generally well tolerated. Results from the current trial suggest that single doses of islatravir as high as 240 mg do not lead to QTc interval prolongation., Competing Interests: R.P.M., Y.L., C.M., K.L.B., S.A.S., and M.I. are current or former employees of Merck Sharp & Dohme LLC, a subsidiary of Merck & Co., Inc., Rahway, NJ, USA, and may own stock and/or options in Merck & Co., Inc., Rahway, NJ, USA. T.O. has no conflicts to disclose.

Introduction: In preclinical cardiovascular safety pharmacology studies, statistical analysis of the rate corrected QT interval (QTc) is the focus for predicting QTc interval changes in the clinic. Modeling of a concentration/QTc relationship, common clinically, is limited due to minimal pharmacokinetic (PK) data in nonclinical testing. It is possible, however, to relate the average drug plasma concentration from sparse PK samples over specific times to the mean corrected QTc. We hypothesize that averaging drug plasma concentration and the QTc-rate relationship over time provides a simple, accurate concentration-QTc relationship bridging statistical and concentration/QTc modeling., Methods: Cardiovascular telemetry studies were conducted in non-human primates (NHP; n = 48) and canines (n = 8). Pharmacokinetic samples were collected on separate study days in both species. Average plasma concentrations for specific intervals (CAverage 0-X ) were calculated for moxifloxacin in canines and NHP using times corresponding to super-intervals for the QTc data statistical analysis. The QTc effect was calculated for each super-interval using a linear regression correction incorporating QT and HR data from the whole super-interval. The concentration QTc effects were then modeled., Results: In NHP, a 10.9 ± 0.06 ms (mean ± 95% CI) change in QTc was detected at approximately 1.5× the moxifloxacin plasma concentration that causes a 10 ms QTc change in humans, based on a 0-24 h super-interval. When simulating a drug without QT effects, mock, no effect on QTc was detected at up to 3× the clinical concentration. Similarly, in canines, a 16.6 ± 0.1 ms change was detected at 1.7× critical clinical moxifloxacin concentration, and a 0.04 ± 0.1 ms change was seen for mock., Conclusions: While simultaneous PK and QTc data points are preferred, practical constraints and the need for QTc averaging did not prevent concentration-QTc analyses. Utilizing a 0-24 h super-interval method illustrates a simple and effective method to address cardiovascular questions when preclinical drug exposures exceed clinical concentrations., Competing Interests: Declaration of competing interest The authors do not report any conflicts of interest., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

This phase I thorough QTc, double-blind, randomized, placebo- and positive-controlled, parallel group, multiple-dose study evaluated avacopan's effect on cardiac repolarization using concentration-QTc (C-QTc) as the primary analysis. Avacopan 30 mg b.i.d. (therapeutic dose) was administered orally on days 1 through 7 followed by avacopan 100 mg b.i.d. (supratherapeutic dose) on days 8 through 14 in 29 healthy participants. Moxifloxacin 400 mg and placebo were administered on days 1 and 15 in a nested crossover design for assay sensitivity in separate cohorts to 28 participants. Time-matched plasma concentrations and up to 10 replicate ECGs were obtained on prespecified days at baseline and postdose on days 1, 7, 14, and 15. The mean change from baseline on QTcF for avacopan (-5.5 to 3.5 ms) was similar to placebo (-6.9 to 1.4 ms) across days 1, 7, and 14. The mean effect on ΔΔQTcF (90% CI) was estimated as 1.5 ms (-0.17 to 3.09) and 0.8 ms (-2.41 to 4.05) for 30 and 100 mg avacopan b.i.d. treatments, respectively. Based on the C-QTc analysis, avacopan's effect on ΔΔQTcF >10 ms can be excluded within the observed plasma concentration range of up to ~1220 and ~335 ng/mL for avacopan and active major metabolite, M1, respectively. The estimated population slopes showed a shallow relationship, which was not statistically significant. There was no clinically meaningful effect of avacopan on heart rate or cardiac conduction (PR and QRS intervals). Avacopan appeared to be generally well tolerated in this study population., (© 2024 Amgen Inc. Clinical and Translational Science published by Wiley Periodicals LLC on behalf of American Society for Clinical Pharmacology and Therapeutics.)

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., Competing Interests: The authors declare that they have no financial or non-financial conflicts of interest., (© 2024 Alzahrani et al.)

Background: Knowledge regarding CNS pharmacokinetics of moxifloxacin is limited, with unknown consequences for patients with meningitis caused by bacteria resistant to beta-lactams or caused by TB., Objective: (i) To develop a novel porcine model for continuous investigation of moxifloxacin concentrations within brain extracellular fluid (ECF), CSF and plasma using microdialysis, and (ii) to compare these findings to the pharmacokinetic/pharmacodynamic (PK/PD) target against TB., Methods: Six female pigs received an intravenous single dose of moxifloxacin (6 mg/kg) similar to the current oral treatment against TB. Subsequently, moxifloxacin concentrations were determined by microdialysis within five compartments: brain ECF (cortical and subcortical) and CSF (ventricular, cisternal and lumbar) for the following 8 hours. Data were compared to simultaneously obtained plasma samples. Chemical analysis was performed by high pressure liquid chromatography with mass spectrometry. The applied PK/PD target was defined as a maximum drug concentration (Cmax):MIC ratio >8., Results: We present a novel porcine model for continuous in vivo CNS pharmacokinetics for moxifloxacin. Cmax and AUC0-8h within brain ECF were significantly lower compared to plasma and lumbar CSF, but insignificantly different compared to ventricular and cisternal CSF. Unbound Cmax:MIC ratio across all investigated compartments ranged from 1.9 to 4.3., Conclusion: A single dose of weight-adjusted moxifloxacin administered intravenously did not achieve adequate target site concentrations within the uninflamed porcine brain ECF and CSF to reach the applied TB CNS target., (© The Author(s) 2024. Published by Oxford University Press on behalf of British Society for Antimicrobial Chemotherapy. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Objectives: To develop physiologically based pharmacokinetic (PBPK) models for widely used anti-TB drugs, namely rifampicin, pyrazinamide, isoniazid, ethambutol and moxifloxacin lung pharmacokinetics (PK)-regarding both healthy and TB-infected tissue (cellular lesion and caseum)-in preclinical species and to extrapolate to humans., Methods: Empirical models were used for the plasma PK of each species, which were connected to multicompartment permeability-limited lung models within a middle-out PBPK approach with an appropriate physiological parameterization that was scalable across species. Lung's extracellular water (EW) was assumed to be the linking component between healthy and infected tissue, while passive diffusion was assumed for the drug transferring between cellular lesion and caseum., Results: In rabbits, optimized unbound fractions in intracellular water of rifampicin, moxifloxacin and ethambutol were 0.015, 0.056 and 0.08, respectively, while the optimized unbound fractions in EW of pyrazinamide and isoniazid in mice were 0.25 and 0.17, respectively. In humans, all mean extrapolated daily AUC and Cmax values of various lung regions were within 2-fold of the observed ones. Unbound concentrations in the caseum were lower than unbound plasma concentrations for both rifampicin and moxifloxacin. For rifampicin, unbound concentrations in cellular rim are slightly lower, while for moxifloxacin they are significantly higher than unbound plasma concentrations., Conclusions: The developed PBPK approach was able to extrapolate lung PK from preclinical species to humans and to predict unbound concentrations in the various TB-infected regions, unlike empirical lung models. We found that plasma free drug PK is not always a good surrogate for TB-infected tissue unbound PK., (© The Author(s) 2024. Published by Oxford University Press on behalf of British Society for Antimicrobial Chemotherapy.)

Managing ocular microbial infections typically requires pharmacotherapy using antibiotic eye drops, such as moxifloxacin hydrochloride (MFX), combined with an antifungal agent like amphotericin B (AB). We carried out and validated an LC-MS/MS assay to quantify these compounds in rabbit tear fluid in order to look into the pharmacokinetics of these two drugs. We employed a protein precipitation technique for the extraction of drugs under examination. A Waters Symmetry C 18 column was used to separate the analytes and internal standard. The composition of the mobile phase was like (A) 0.1% v/v formic acid in water and (B) methanol. The detection of MFX and AB was accomplished through the utilization of positive ion electrospray ionization under multiple reaction monitoring mode. The linearity curves for both analytes exhibited an acceptable trendline across a concentration range of 2.34-300 ng/mL for MFX and 7.81-1000 ng/mL for AB in surrogate rabbit tear fluid. The lower limit of quantitation for MFX was 2.34 ng/mL, while for AB, it was 7.81 ng/mL. The approach was strictly validated, encompassing tests of selectivity, linearity (with r 2  > 0.99), precision, accuracy, matrix effects, and stability. Consequently, we employed this method to evaluate the pharmacokinetics profiles of MFX and AB in rabbit tear fluid following single topical doses., (© 2024 John Wiley & Sons Ltd.)

The current study goal was to improve mucoadhesive potential and ocular pharmacokinetics of nanoparticles of thiolated xyloglucan (TXGN) containing moxifloxacin (MXF). Thiolation of xyloglucan (XGN) was achieved with esterification with 3-mercaptopropionic acid. TXGN was characterized by NMR and FTIR analysis. The nanoparticles of TXGN were prepared using ionic-gelation method and evaluate the antibacterial properties. TXGN and nanoparticles were determined to possess 0.06 and 0.08 mmol of thiol groups/mg of polymer by Ellman's method. The ex-vivo bioadhesion time of TXGN and nanoparticles was higher than XGN in a comparative assessment of their mucoadhesive properties. The creation of a disulfide link between mucus and TXGN is responsible for the enhanced mucoadhesive properties of TXGN (1-fold) and nanoparticles (2-fold) over XGN. Improved MXF penetration in nanoparticulate formulation (80 %) based on TXGN was demonstrated in an ex-vivo permeation research utilizing rabbit cornea. Dissolution study showed 95 % release of MXF from nanoparticles. SEM images of nanoparticles showed spherical shape and cell viability assay showed nontoxic behavior when tested on RPE cell line. Antibacterial analysis revealed a zone of inhibition of 31.5 ± 0.5 mm for MXF, while NXM3 exhibited an expanded zone of 35.5 ± 0.4 mm (p < 0.001). In conclusion, thiolation of XGN improves its bioadhesion, permeation, ocular-retention and pharmacokinetics of MXF., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: The simultaneous use of NSAIDs and antibiotics is recommended for bacterial diseases in human and veterinary medicine. Moxifloxacin (MFX) and dexketoprofen (DEX) can be used simultaneously in bacterial infections. However, there are no studies on how the simultaneous use of DEX affects the pharmacokinetics of MFX in rats., Objectives: The aim of this study was to determine the effect of DEX on plasma and lung pharmacokinetics of MFX in male and female rats., Methods: A total of 132 rats were randomly divided into 2 groups: MFX (n=66, 33 males/33 females) and MFX+DEX (n=66, 33 females/33 males). MFX at a dose of 20 mg/kg and DEX at a dose of 25 mg/kg were administered intraperitoneally. Plasma and lung concentrations of MFX were determined using the highperformance liquid chromatography-UV and pharmacokinetic parameters were evaluated by noncompartmental analysis., Results: Simultaneous administration of DEX increased the plasma and lung area under the curve from 0 to 8 h (AUC 0-8 ) and peak concentration (C max ) of MFX in rats, while it significantly decreased the total body clearance (CL/F). When female and male rats were compared, significant differences were detected in AUC 0-8 , C max , CL/F and volume of distribution. The AUC 0-8lung /AUC 0-8plasma ratios of MFX were calculated as 1.68 and 1.65 in female rats and 5.15 and 4.90 in male rats after single and combined use, respectively., Conclusion: MFX was highly transferred to the lung tissue and this passage was remarkably higher in male rats. However, DEX administration increased the plasma concentration of MFX in both male and female rats but did not change its passage to the lung. However, there is a need for a more detailed investigation of the difference in the pharmacokinetics of MFX in male and female rats., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Background. Moxifloxacin is currently recommended at a dose of 7.5–10 mg/kg for children with multidrug-resistant (MDR) tuberculosis, but pharmacokinetic and long-term safety data of moxifloxacin in children with tuberculosis are lacking. An area under the curve (AUC) of 40–60 μg × h/mL following an oral moxifloxacin dose of 400 mg has been reported in adults. Methods. In a prospective pharmacokinetic and safety study, children 7–15 years of age routinely receiving moxifloxacin 10 mg/kg daily as part of multidrug treatment for MDR tuberculosis in Cape Town, South Africa, for at least 2 weeks, underwent intensive pharmacokinetic sampling (predose and 1, 2, 4, 8, and either 6 or 11 hours) and were followed for safety. Assays were performed using liquid chromatography–tandem mass spectrometry, and pharmacokinetic measures calculated using noncompartmental analysis. Results. Twenty-three children were included (median age, 11.1 years; interquartile range [IQR], 9.2–12.0 years); 6 of 23 (26.1%) were human immunodeficiency virus (HIV)-infected. The median maximum serum concentration (Cmax), area under the curve from 0–8 hours (AUC0–8), time until Cmax (Tmax), and half-life for moxifloxacin were 3.08 (IQR, 2.85–3.82) μg/mL, 17.24 (IQR, 14.47–21.99) μg × h/mL, 2.0 (IQR, 1.0–8.0) h, and 4.14 (IQR, 3.45–6.11), respectively. Three children, all HIV-infected, were underweight for age. AUC0–8 was reduced by 6.85 μg × h/mL (95% confidence interval, −11.15 to −2.56) in HIV-infected children. Tmax was shorter with crushed vs whole tablets (P = .047). Except in 1 child with hepatotoxicity, all adverse effects were mild and nonpersistent. Mean corrected QT interval was 403 (standard deviation, 30) ms, and no prolongation >450 ms occurred. Conclusions. Children 7–15 years of age receiving moxifloxacin 10 mg/kg/day as part of MDR tuberculosis treatment have low serum concentrations compared with adults receiving 400 mg moxifloxacin daily. Higher moxifloxacin dosages may be required in children. Moxifloxacin was well tolerated in children treated for MDR tuberculosis. [ABSTRACT FROM AUTHOR]

Moxifloxacin has an important role in the treatment of tuberculosis (TB). Unfortunately, coadministration with the cornerstone TB drug rifampicin results in suboptimal plasma exposure. We aimed to gain insight into the moxifloxacin pharmacokinetics and the interaction with rifampicin. Moreover, we provided a mechanistic framework to understand moxifloxacin pharmacokinetics. We developed a physiologically based pharmacokinetic model in Simcyp version 19, with available and newly generated in vitro and in vivo data, to estimate pharmacokinetic parameters of moxifloxacin alone and when administered with rifampicin. By combining these strategies, we illustrate that the role of P-glycoprotein in moxifloxacin transport is limited and implicate MRP2 as transporter of moxifloxacin-glucuronide followed by rapid hydrolysis in the gut. Simulations of multiple dose area under the plasma concentration-time curve (AUC) of moxifloxacin (400 mg once daily) with and without rifampicin (600 mg once daily) were in accordance with clinically observed data (predicted/observed [P/O] ratio of 0.87 and 0.80, respectively). Importantly, increasing the moxifloxacin dose to 600 mg restored the plasma exposure both in actual patients with TB as well as in our simulations. Furthermore, we extrapolated the single dose model to pediatric populations (P/O AUC ratios, 1.04-1.52) and the multiple dose model to children with TB (P/O AUC ratio, 1.51). In conclusion, our combined approach resulted in new insights into moxifloxacin pharmacokinetics and accurate simulations of moxifloxacin exposure with and without rifampicin. Finally, various knowledge gaps were identified, which may be considered as avenues for further physiologically based pharmacokinetic refinement., (© 2021 The Authors. The Journal of Clinical Pharmacology published by Wiley Periodicals LLC on behalf of American College of Clinical Pharmacology.)

Background/objective: Moxifloxacin is a fluoroquinolone that is commonly used in adults, but not children. Certain clinical situations compel pediatric clinicians to use moxifloxacin, despite its potential for toxicity and limited pharmacokinetics (PK) data. Our objective was to further characterize the pharmacokinetics of moxifloxacin in children., Methods: We performed an opportunistic, open-label population PK study of moxifloxacin in children < 18 years of age who received moxifloxacin as part of standard care. A set of structural PK models and residual error models were explored using nonlinear mixed-effects modeling. Covariates with known biological relationships were investigated for their influence on PK parameters., Results: We obtained 43 moxifloxacin concentrations from 14 participants who received moxifloxacin intravenously (n = 8) or orally (n = 6). The dose of moxifloxacin was 10 mg/kg daily in participants ≤ 40 kg and 400 mg daily in participants > 40 kg. The population mean clearance and mean volume of distribution were 18.2 L/h and 167 L, respectively. The oral absorption was described by a first-order process. The estimated extent of oral bioavailability was highly variable (range 20-91%). Total body weight was identified as a covariate on clearance and volume of distribution, and substantially reduced the random unexplained inter-individual variability for both parameters. No participants experienced suspected serious adverse reactions related to moxifloxacin., Conclusion: These data add to the existing literature to support use of moxifloxacin in children in certain situations; however, further prospective studies on the safety and efficacy of moxifloxacin are needed., (© 2022. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Background: Peri and postoperative antibiotics are key adjuvant treatment tools in the management of periprosthetic joint infection (PJI). The aim of this study was to evaluate the effect of rifampicin on the area under the moxifloxacin concentration-time curve from 0 to 24 hours (AUC0-24) in the synovial fluid of the knee joint, tibial bone, and adjacent subcutaneous tissue under steady-state conditions using microdialysis in a porcine model., Methods: Twenty female pigs were randomized to receive oral treatment with moxifloxacin monotherapy (Group A, n = 10) of 400 mg once daily for 3 days or a combination therapy (Group B, n = 10) of 400 mg of moxifloxacin once daily for 3 days and 450 mg of rifampicin twice daily for 7 days. Microdialysis was used for sampling the synovial fluid of the knee joint, tibial cancellous and cortical bone, and adjacent subcutaneous tissues. Plasma samples were taken as a reference. Measurements were obtained for 24 hours., Results: Coadministration of moxifloxacin and rifampicin resulted in reductions of the moxifloxacin AUC0-24 in all targeted tissue compartments by 67% to 85% (p < 0.05). The corresponding change in plasma was 20% (p = 0.49). For both groups, the tissue penetration (the ratio of tissue free fraction AUC0-24 to plasma free fraction AUC0-24 [fAUCtissue/fAUCplasma]) was incomplete in all investigated compartments. The highest moxifloxacin tissue penetration was in the knee joint synovial fluid: 0.59 (Group A) and 0.24 (Group B). The lowest tissue penetration was in the cortical bone: 0.17 (Group A) and 0.03 (Group B)., Conclusions: We found a significant reduction of the moxifloxacin concentration, expressed as the AUC0-24, in tissues relevant to acute PJI treatment when coadministered with rifampicin., Clinical Relevance: The concentrations within the targeted tissue compartments were reduced significantly more than the concentrations in plasma, which may be particularly important as plasma concentrations are used in clinical practice to assess moxifloxacin treatment sufficiency., Competing Interests: Disclosure: The Disclosure of Potential Conflicts of Interest forms are provided with the online version of the article (http://links.lww.com/JBJS/G769)., (Copyright © 2021 by The Journal of Bone and Joint Surgery, Incorporated.)

The aim of our study was to prepare nanoparticles of disulfide bridged thiolated chitosan and eudragit RS100 using the air oxidation method for controlled drug delivery. The developed nanoparticles were characterized by FTIR, DSC, TGA, zeta sizer, zeta potential, SEM and 1 H NMR. The loading, entrapment efficiency and in-vitro release of moxifloxacin from nanoparticles was determined. Toxicity was studied using Caco-2 cell line and pharmacokinetics of moxifloxacin from the developed nanoparticles was studied in albino rats. The FTIR analysis showed no chemical interaction of the drug with the thiolated polymers. The DSC and TGA showed the thermal stability of nanoparticles. The average particle size of nanoparticles was 87 nm, zeta potential of NTC3 was ± 19 and SEM showed the spherical shape of nanoparticles. The 1 H NMR spectra confirmed the structure of thiolated chitosan and eudragit RS100. The loading, encapsulation efficiency and release of moxifloxacin from NTC3 were 100.3%, 89.67% and 88.49% respectively. The nanoparticles in culture medium did not affect the viability of Caco-2 cells. The NTC3 formulation showed a greater bioavailability of moxifloxacin compared to the reference formulation. The study reports a convenient and effective way to prepare a chitosan and eudragit RS100 based drug delivery system with a controlled release pattern., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Microbial keratitis (MK) is a vision-threatening disease and the fourth leading cause of blindness worldwide. In this work, we aim to develop moxifloxacin (MXN)-loaded chitosan-based cationic mucoadhesive polyelectrolyte nanocapsules (PENs) for the effective treatment of MK. PENs were formulated by polyelectrolyte complex coacervation method and characterized for their particle size, surface charge, morphology, mucoadhesive property, in-vitro and ex-vivo release, ocular tolerance, and antimicrobial efficacy studies. The pharmacodynamic study was conducted on rabbit eye model of induced keratitis and it is compared with marketed formulation (MF). Developed PENs showed the size range from 230.7 ± 0.64 to 249.0 ± 0.49 nm and positive surface charge, spherical shape along with appropriate physico-chemical parameters. Both in-vitro and ex-vivo examination concludes that PENs having more efficiency in sustained release of MXN compared to MF. Ocular irritation studies demonstrated that no corneal damage or ocular irritation. The in-vivo study proved that the anti-bacterial efficacy of PENs was improved when compared with MF. These results suggested that PENs are a feasible choice for MK therapy because of their ability to enhance ocular retention of loaded MXN through interaction with the corneal surface of the mucous membrane.

To prevent antibiotic-induced perturbations on gut microbiota, DAV132, a novel colon-targeted adsorbent, which sequesters antibiotic residues in the lower gastrointestinal tract, was developed. We built an integrated pharmacological model of how DAV132 reduces fecal free moxifloxacin and preserves gut microbiota. We used plasma and fecal free moxifloxacin concentrations, and Shannon diversity index from 16S ribosomal RNA gene metagenomics analysis of fecal microbiota, of 143 healthy volunteers assigned randomly to receive moxifloxacin only, or with 10 DAV132 dose regimens, or to a control group. We modeled reduced fecal moxifloxacin concentrations using a transit model for DAV132 kinetics and a Michaelis-Menten model with an effect of the amount of activated charcoal on adsorption efficacy. Changes in moxifloxacin-induced perturbations on gut microbiota diversity were then quantified through a turnover model with the Emax model. With the developed model, the efficiency of pharmacokinetic antagonism and its consequences on gut microbiota diversity were quantified., (© 2020 The Authors Clinical Pharmacology & Therapeutics © 2020 American Society for Clinical Pharmacology and Therapeutics.)

Concentration-QTc (C-QTc) modeling is being increasingly used in phase 1 studies. For studies without a placebo arm (single arm studies), the scientific whitepaper by Garnett et al. ( https://doi.org/10.1007/s10928-017-9558-5 ) states that time-matched baseline adjustments may minimize the effect of diurnal variation in QTc intervals, and categorical time effects are not needed in the model. However, how diurnal variations can be accounted for when only pre-dose baselines are available is unclear. This research investigates whether including categorical time effects in the model can adjust diurnal variation in single arm studies with pre-dose baselines, where QTc prolongation is evaluated at a concentration of interest based on ΔQTc at 24 h and ΔΔQTc (a model-derived difference in ΔQTc from concentration zero). To understand the operating characteristics for the models with and without categorical time effects, simulations were conducted under various scenarios considering oncology early phase studies. When the C-QTc relationship is linear, models without categorical time effects provided biased estimates for model parameters and inflated or decreased false negative rates (FNRs) depending on the pattern of diurnal variations in QTc intervals, whereas models with categorical time effects caused no biases and controlled the FNRs. For non-linear C-QTc relationships, ΔΔQTc estimations made using the model with categorical time effects were not robust. Thus, for single arm studies where only pre-dose baselines are available, we recommend collecting QTc measurements at 24 h and estimating ΔQTc at a concentration of interest at 24 h using the C-QTc model with categorical time effects.

To investigate the effect of simulated weightlessness on the pharmacokinetics of orally administered moxifloxacin and the antacid Maalox or the antidiarrheal Pepto-Bismol using a tail-suspended (TS) rat model of microgravity. Fasted control and TS, jugular-vein-cannulated, male Sprague-Dawley rats received either a single 5 mg/kg intravenous dose or a single 10 mg/kg oral dose of moxifloxacin alone or with a 0.625 mL/kg oral dose of Maalox or a 1.43 mL/kg oral dose of Pepto-Bismol. Plasma concentrations of moxifloxacin were measured by HPLC. Pharmacokinetic data were analyzed using WinNonlin. Simulated weightlessness had no effect on moxifloxacin disposition after intravenous administration but significantly decreased the extent of moxifloxacin oral absorption. The coadministration of moxifloxacin with Maalox to either control or TS rats caused significant reductions in the rate and extent of moxifloxacin absorption. In contrast, the coadministration of moxifloxacin with Pepto-Bismol to TS rats had no significant effect on either the rate or the extent of moxifloxacin absorption. These interactions showed dose staggering when oral administrations of Pepto-Bismol and moxifloxacin were separated by 60 min in control rats but not in TS rats. Dose staggering was more apparent after the coadministration of Maalox and moxifloxacin in TS rats.

This study evaluated the effect of 3 doses of a trazodone hydrochloride 6% oral drops solution on the QT interval of healthy volunteers. Subjects were randomly assigned to receive a single dose of trazodone 20 mg, 60 mg, and 140 mg, moxifloxacin 400 mg, and trazodone-matched placebo in 5 periods separated by 7-day washouts, according to a double-blind, crossover study design. Subjects were monitored continuously, and triplicate ECGs were extracted from baseline (predose) until 24 hours postdose. Blood samples for trazodone and moxifloxacin analyses were collected at the same time points. The concentration-QTc relationship assessed on placebo-adjusted change from baseline for Fridericia-corrected QT (ΔΔQTcF) was the primary end point. ΔΔQTcF values of 4.5, 12.3, and 19.8 ms for the 20-, 60-, and 140-mg doses were observed at the corresponding trazodone peak plasma concentrations. The upper bound of the 90%CI exceeded 10 ms for the 60- and the 140-mg doses. Time-matched analysis results were in line with these findings. No significant trazodone effect on heart rate or PR or QRS intervals and no clinically significant new morphological changes were present. In this moxifloxacin-validated ECG trial, trazodone had a modest, dose-dependent effect on cardiac repolarization, with no QTc prolongation observed with the 20-mg dose and an effect exceeding the values set in E14 guideline with the 60- and 140-mg doses. The effect on cardiac repolarization is unlikely to represent a clinical risk for ventricular proarrhythmia, but caution should be used with concomitant use of other medications that prolong QT or increase trazodone exposure., (© 2020 The Authors. The Journal of Clinical Pharmacology published by Wiley Periodicals LLC on behalf of American College of Clinical Pharmacology.)

Purpose: To elucidate the relationship between antofloxacin (AT) plasma concentration and QT interval prolongation, compare the effects of different correction and analytical methods on conclusions, and estimate the possible false-positive rate in thorough QT (TQT) studies., Methods: Twenty-four healthy Chinese volunteers from a four-period crossover TQT study orally received 200 mg/d AT, 400 mg/d AT, 400 mg/d moxifloxacin, and a placebo in a random order for 5 d for each. QT interval samples were collected on d 1 and d 5. Population models were established describing the relationship between QT and AT concentration. The yardstick from ICH E14 guidelines was used to measure the effect of drugs on QT prolongation both in biostatistical and modeling analyses. A possible false-positive rate was estimated by constructing a 1000-time bootstrap to obtain the rate-of-difference values between d 1 and d 5 over 5 ms in the placebo period., Results: In the modeling analysis, the QT prolongation estimate at the mean maximal concentration of AT (4.51 μg/mL) was 3.84 ms, and its upper bound of the one-sided 95 % CI was 7.04 ms, which showed a negative effect on QT interval prolongation. The estimation for the false-positive rate was 31 % in this study., Conclusion: The effect of AT on QT interval prolongation may not have been significant at the dosage of 400 mg. Baseline and placebo adjustments were necessary in TQT studies. Population modeling has demonstrated clear superiority in making full use of data to accurately analyze the relationship between drugs and QT intervals., (Copyright © 2020 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

A female infant underwent myelomeningocele repair and developed persistent ventricular dilatation. Cerebrospinal fluid (CSF) indices demonstrated meningitis with cultures growing Mycoplasma hominis. The infant was treated with multiple antibiotics including moxifloxacin. Moxifloxacin CSF levels were obtained for pharmacokinetic analysis. This case report adds the importance of understanding the pharmacokinetics of CSF moxifloxacin levels among infants.

We analyzed the effects of intravenously as well as orally administered moxifloxacin on the pharmacokinetic and electrocardiographic variables along with its torsadogenic action using the chronic atrioventricular block cynomolgus monkeys with a cross-over design. Initially, moxifloxacin was intravenously administered in doses of 60 mg/kg/2 h, 60 mg/kg/1 h and 105 mg/kg/1.75 h with an interval of >1 week (n = 3), which provided C max of 19.7, 25.4 and 37.8 μg/mL, and induced torsade de pointes in 1, 0 and 3 out of 3 animals, respectively. Next, moxifloxacin was orally administered in doses of 10, 30 and 100 mg/kg with an interval of >1 week (n = 6), which provided C max of 1.8, 4.2 and 8.9 μg/mL, and induced torsade de pointes in 0, 0 and 2 out of 6 animals, respectively. A close analysis of pharmacokinetic and electrocardiographic variables indicates that torsade de pointes was induced in animals that had experienced larger systemic exposure of moxifloxacin and/or greater peak QTcF, although C max by itself did not necessarily reflect the incidence of torsade de pointes when its administration route was different. These findings may provide a basic guide how to use moxifloxacin in safe for patients with labile repolarization process., Competing Interests: Declaration of Competing Interest The authors indicated no potential conflict of interest except for Mr. Kengo Sakamoto who was employee of Ina Research Inc., (Copyright © 2020 The Authors. Production and hosting by Elsevier B.V. All rights reserved.)

In this study, the pharmacokinetics of moxifloxacin (5 mg/kg) was determined following a single intravenous administration of moxifloxacin alone and co-administration with diclofenac (2.5 mg/kg) or flunixin meglumine (2.2 mg/kg) in sheep. Six healthy Akkaraman sheep (2 ± 0.3 years and 53.5 ± 5 kg of body weight) were used. A longitudinal design with a 15-day washout period was used in three periods. In the first period, moxifloxacin was administered by an intravenous (IV) injection. In the second and third periods, moxifloxacin was co-administered with IV administration of diclofenac and flunixin meglumine, respectively. The plasma concentration of moxifloxacin was assayed by high-performance liquid chromatography. The pharmacokinetic parameters were calculated using a two-compartment open pharmacokinetic model. Following IV administration of moxifloxacin alone, the mean elimination half-life (t 1/2β ), total body clearance (Cl T ), volume of distribution at steady state (V dss ) and area under the curve (AUC) of moxifloxacin were 2.27 hr, 0.56 L h -1  kg -1 , 1.66 L/kg and 8.91 hr*µg/ml, respectively. While diclofenac and flunixin meglumine significantly increased the t 1/2β and AUC of moxifloxacin, they significantly reduced the Cl T and V dss . These results suggest that anti-inflammatory drugs could increase the therapeutic efficacy of moxifloxacin by altering its pharmacokinetics., (© 2020 John Wiley & Sons Ltd.)

Background: Bacterial conjunctivitis is a serious ocular infection if left untreated. It is caused by several species of bacteria like Pseudomonas, Staphylococcus and Mycobacterium., Objective: The present investigation explores the development and characterization of moxifloxacin hydrochloride and ketorolac tromethamine combination loaded Eudragit RL 100 nanosuspension for ocular drug delivery in order to overcome the problems associated with conventional dosage forms., Methods: The nanosuspension prepared by nanoprecipitation technique showed successful entrapment of both water-soluble drugs in the polymer matrix indicated by their % entrapment efficiencies., Results: Formulations showed a mean particle size <200 nm with narrow size distribution and positive surface charge due to the presence of quaternary ammonium groups of Eudragit RL100. FTIR study revealed compatibility among the components, while a reduction in the crystallinity of formulation was observed in the PXRD study. The release of both the drugs was found to be sustained in nanosuspension as compared to commercial eyedrops. Ex vivo studies showed increased transcorneal permeation of drugs from nanosuspension, where approximately 2.5-fold and 2-fold increase in the permeation was observed for moxifloxacin hydrochloride and ketorolac tromethamine, respectively. The formulation was stable at 4°C and room temperature., Conclusion: Due to their sustained release, positive surface charge and higher transcorneal permeation, this will be a promising ocular drug delivery., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Clinical studies of new antitubercular drugs are costly and time-consuming. Owing to the extensive tuberculosis (TB) treatment periods, the ability to identify drug candidates based on their predicted clinical efficacy is vital to accelerate the pipeline of new therapies. Recent failures of preclinical models in predicting the activity of fluoroquinolones underline the importance of developing new and more robust predictive tools that will optimize the design of future trials. Here, we used high-content imaging screening and pharmacodynamic intracellular (PDi) modeling to identify and prioritize fluoroquinolones for TB treatment. In a set of studies designed to validate this approach, we show moxifloxacin to be the most effective fluoroquinolone, and PDi modeling-based Monte Carlo simulations accurately predict negative culture conversion (sputum sterilization) rates compared to eight independent clinical trials. In addition, PDi-based simulations were used to predict the risk of relapse. Our analyses show that the duration of treatment following culture conversion can be used to predict the relapse rate. These data further support that PDi-based modeling offers a much-needed decision-making tool for the TB drug development pipeline., (Copyright © 2019 Donnellan et al.)

Purpose: Celecoxib is a selective cyclooxygenase-2 inhibitor widely used in patients with osteoarthritis and rheumatoid arthritis. Recently, nonclinical data on the inhibition of human ether-à-go-go-related gene potassium channels by celecoxib were reported, but there is no compelling evidence for this finding in humans. The aim of this study was to assess the potential effects of celecoxib on cardiac repolarization by conducting a thorough QT study, which was designed in compliance with the related guidelines., Methods: This randomized, open-label, positive- and negative-controlled, crossover clinical study was conducted in healthy male and female subjects. Each subject received, in 1 of 4 randomly assigned sequences, all of the following 3 interventions: celecoxib 400 mg once daily for 6 days; a single dose of moxifloxacin 400 mg, which served as a positive control to assess the assay sensitivity; and water without any drug, which served as a negative control. Serial 12-lead ECG and blood samples for pharmacokinetic analysis were collected periodically over 24 h. Individually RR-corrected QT intervals (QTcI) and Fridericia method-corrected QT intervals (QTcF) were calculated and evaluated., Findings: Twenty-eight subjects were allocated to 1 of the 4 intervention sequences. The largest time-matched mean effects of celecoxib on the QTcI and QTcF were <5 ms, and the upper bounds of the 1-sided 95% CIs of those values did not exceed 10 ms. Moreover, none of the subjects had an absolute QTcI value of >450 ms or a change from baseline in QTcI of >60 ms after multiple administrations of celecoxib. The QTcI did not show a positive correlation with celecoxib concentrations in the range up to ~2700 μg/L. The overall effects of moxifloxacin on the QTcI and QTcF were enough to establish assay sensitivity. No serious adverse events were reported, with a total of 11 AEs reported in 8 subjects., Implications: Celecoxib caused no clinically relevant increase in the QT/QTc interval at the maximum dose level used in current practice settings. ClinicalTrials.gov identifier: NCT03822520., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Purpose: To create a model of the abatement profiles of the three most commonly employed endophthalmitis prophylaxis intracameral (IC) antibiotics-cefuroxime, vancomycin, and moxifloxacin-to enable comparison of their durations of efficacy against common endophthalmitis pathogens., Settings: Humber River Hospital and The Eye Foundation of Canada, Toronto, Ontario, the University of Toronto, Ontario, and McGill University, Montreal, Quebec, Canada., Design: Literature review, as well as review of our clinical experience with 4797 consecutive cases with IC vancomycin, followed by 9185 consecutive cases with IC moxifloxacin., Methods: A detailed review of the prophylactic antibiotic literature was performed. Exponential decay models of the selected IC antibiotics were updated from previous work by the study authors with decay constants adjusted to agree with the available published objective data., Results: The graphs generated by the study data demonstrate the relative duration of IC bactericidal activity of moxifloxacin, cefuroxime, and vancomycin. They suggest that at present, IC moxifloxacin, when administered in appropriate doses, is the most effective agent in preventing postoperative endophthalmitis. Unlike vancomycin and cefuroxime, bacterial resistance to moxifloxacin is dose-dependent, and it is overcome in the vast majority of cases with doses that can safely be achieved intracamerally. The graphs can serve as a useful tool to assess the expected efficacy of each antibiotic in reference to local pathogen resistances., Conclusion: The model shows IC moxifloxacin, cefuroxime, and vancomycin durations of bactericidal efficacy post-cataract surgery, which correlate well with the published objective data., (Copyright © 2019 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.)

Background: Immunocompromised individuals and those with lung dysfunction readily acquire pulmonary bacterial infections, which may cause serious diseases and carry a heavy economic burden. Maintaining adequate antibiotic concentrations in the infected tissues is necessary to eradicate resident bacteria. To specifically deliver therapeutics to the infected pulmonary tissues and enable controlled release of payloads at the infection site, a ROS-responsive material, i.e. 4-(hydroxymethyl) phenylboronic acid pinacol ester-modified α-cyclodextrin (Oxi-αCD), was employed to encapsulate moxifloxacin (MXF), generating ROS-responsive MXF-containing nanoparticles (MXF/Oxi-αCD NPs)., Results: MXF/Oxi-αCD NPs were coated with DSPE-PEG and DSPE-PEG-folic acid, facilitating penetration of the sputum secreted by the infected lung and enabling the active targeting of macrophages in the inflammatory tissues. In vitro drug release experiments indicated that MXF release from Oxi-αCD NPs was accelerated in the presence of 0.5 mM H 2 O 2 . In vitro assay with Pseudomonas aeruginosa demonstrated that MXF/Oxi-αCD NPs exhibited higher antibacterial activity than MXF. In vitro cellular study also indicated that folic acid-modified MXF/Oxi-αCD NPs could be effectively internalized by bacteria-infected macrophages, thereby significantly eradicating resident bacteria in macrophages compared to non-targeted MXF/Oxi-αCD NPs. In a mouse model of pulmonary P. aeruginosa infection, folic acid-modified MXF/Oxi-αCD NPs showed better antibacterial efficacy than MXF and non-targeted MXF/Oxi-αCD NPs. Meanwhile, the survival time of mice was prolonged by treatment with targeting MXF/Oxi-αCD NPs., Conclusions: Our work provides a strategy to overcome the mucus barrier, control drug release, and improve the targeting capability of NPs for the treatment of pulmonary bacterial infections.

Postoperative local infection is a major complication after pancreatic surgery. The aim of this prospective clinical trial was to assess the potential of moxifloxacin (MXF) to treat pancreatic infections from a pharmacokinetic (PK)/pharmacodynamic (PD) perspective. The PK of MXF in serum and pancreatic juice, via an inserted tube in the pancreatic duct, was determined in 19 patients up to day 7 after pancreatoduodenectomy. PK data in both specimens was analyzed with NONMEM 7.3. Intraoperative swipes were performed for microbiological examination. PK/PD target attainment was assessed in both matrices using unbound area under the plasma concentration-time curve/minimum inhibitory concentration (MIC) targets of ≥30 and ≥100, for gram-positive and gram-negative pathogens, respectively. A 2-compartment population PK model in which the measurements in pancreatic juice were assigned to a scaled peripheral compartment best described the PK in both specimens simultaneously. Median (10th-90th percentile) area under the plasma concentration-time curve values after the third dose were 28.9 mg · h/L (18.6-42.0) in serum and 55.8 mg · h/L (23.7-81.4) in pancreatic juice. Target attainment rate for the intraoperatively isolated bacterial strains was ≥0.88 after the third MXF dose. For gram-negatives, high probability of target attainment ≥0.84 was observed in serum for MIC ≤ 0.125 mg/L and in pancreatic juice for MIC ≤ 0.25 mg/L. For gram-positives, the probability of target attainment was 0.84-1 in serum for MIC ≤ 0.5 mg/L and in pancreatic juice for MIC ≤ 1 mg/L. In conclusion, penetration of MXF into pancreatic juice was substantial. The PK/PD analysis indicated that treatment of pancreatic infections by isolates with MIC ≤ 0.25 mg/L (gram-negative) and ≤1 mg/L (gram-positive) should be evaluated in further studies., (© 2019, The American College of Clinical Pharmacology.)

Concentration-QTc modeling was applied to pretomanid, a new nitroimidazooxazine antituberculosis drug. Data came from eight phase 2 and phase 3 studies. Besides pretomanid alone, various combinations with bedaquiline, linezolid, moxifloxacin, and pyrazinamide were considered; special attention was given to the bedaquiline-pretomanid-linezolid (BPaL) regimen that has demonstrated efficacy in the Nix-TB study in subjects with extensively drug-resistant or treatment-intolerant or nonresponsive multidrug-resistant tuberculosis. Three heart rate corrections to QT were considered: Fridericia's QTcF, Bazett's QTcB, and a population-specific correction, QTcN. QTc increased with the plasma concentrations of pretomanid, bedaquiline's M2 metabolite, and moxifloxacin in a manner described by a linear model in which the three slope coefficients were constant across studies, visits within study, and times postdose within visit but where the intercept varied across those dimensions. The intercepts tended to increase on treatment to a plateau after several weeks, a pattern termed the secular trend. The slope terms were similar for the three QTc corrections, but the secular trends differed, suggesting that at least some of the secular trend was due to the elevated heart rates of tuberculosis patients decreasing to normal levels on treatment. For pretomanid 200 mg once a day (QD) alone, a typical steady-state maximum concentration of drug in plasma ( C max ) resulted in a mean change from baseline of QTcN of 9.1 ms, with an upper 90% confidence interval (CI) limit of 10.2 ms. For the BPaL regimen, due to the additional impact of the bedaquiline M2 metabolite, the corresponding values were 13.6 ms and 15.0 ms. The contribution to these values from the secular trend was 4.0 ms., (Copyright © 2019 Li et al.)

Background: For an effective antimicrobial treatment, it is crucial that antibiotics reach sufficient concentrations in plasma and tissue. Currently no data exist regarding moxifloxacin plasma concentrations and exposure levels in tissue under septic conditions., Objectives: To determine the pharmacokinetics of moxifloxacin in plasma and interstitial space fluid over a prolonged period., Patients and Methods: Ten septic patients were treated with 400 mg of moxifloxacin once a day; on days 1, 3 and 5 of treatment plasma sampling and microdialysis in the subcutis and muscle of the upper thigh were performed to determine concentrations of moxifloxacin in different compartments. This trial was registered in the German Clinical Trials Register (DRKS, register number DRKS00012985)., Results: Mean unbound fraction of moxifloxacin in plasma was 85.5±3.4%. On day 1, Cmax in subcutis and muscle was 2.8±1.8 and 2.5±1.3 mg/L, respectively, AUC was 24.8±15.1 and 21.3±10.5 mg·h/L, respectively, and fAUC0-24/MIC was 100.9±62.9 and 86.5±38.3 h, respectively. Cmax for unbound moxifloxacin in plasma was 3.5±0.9 mg/L, AUC was 23.5±7.5 mg·h/L and fAUC0-24/MIC was 91.6±24.8 h. Key pharmacokinetic parameters on days 3 and 5 showed no significant differences. Clearance was higher than in healthy adults, but tissue concentrations were comparable, most likely due to a lower protein binding., Conclusions: Surprisingly, the first dose already achieved exposure comparable to steady-state conditions. The approved daily dose of 400 mg was adequate in our patient population. Thus, it seems that in septic patients a loading dose on the first day of treatment with moxifloxacin is not required., (© The Author(s) 2019. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

The study was designed to fabricate the moxifloxacin nanostructured lipid carriers (MOX-NLCs) loaded in situ gel for opthalmic application to improve the corneal permeation and retention and also subside the toxic effect associated with intracameral injection of moxifloxacin in endophthalmitis treatment. Initially, Box-Behnken design was used to optimize the various factors significantly affecting the final formulation attributes. MOX-NLCs with particle size 232.1 ± 9.2 nm, polydispersity index 0.247 ± 0.031, zeta potential -16.3 ± 1.6 mV, entrapment efficiency 63.1 ± 2.4%, and spherical shape was achieved. The optimized MOX-NLCs demonstrated the Higuchi release kinetics with highest regression coefficient. Besides this, FTIR, differential scanning calorimetry, and X-ray diffraction results suggested that MOX had excellent compatibility with excipients. Furthermore, the results of ex-vivo permeation study demonstrated 2-fold higher permeation (208.7 ± 17.6 μg), retention (37.26 ± 2.83 μg), and flux (9.57 ± 0.73 μg/cm 2 h) compared with free MOX in situ gel. In addition, MOX-NLCs exhibited normal corneal hydration and did not show any sign of structural damage to the corneal tissue as confirmed by histology. Therefore, the findings strongly suggest that MOX-NLCs in situ gel with higher permeation and retention can be a better alternative strategy to prevent and treat the endophthalmitis infection., (Copyright © 2019 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.)

Moxifloxacin is a widely used fluoroquinolone for the treatment of complicated intra-abdominal infections. We applied physiologically-based pharmacokinetic (PBPK) and population pharmacokinetic (popPK) modeling to support dose selection in pediatric patients. We scaled an existing adult PBPK model to children based on prior physiological knowledge. The resulting model proposed an age-dependent dosing regimen that was tested in a phase I study. Refined doses were then tested in a phase III study. A popPK analysis of all clinical pediatric data confirmed the PBPK predictions, including the proposed dosing schedule in children, and supported pharmacokinetics-related safety/efficacy questions. The pediatric PBPK model adequately predicted the doses necessary to achieve antimicrobial efficacy while maintaining safety in the phase I and III pediatric studies. Altogether, this study retroactively demonstrated the robustness and utility of modeling to support dose finding and confirmation in pediatric drug development for moxifloxacin., (© 2019 Bayer AG, Leverkusen Germany CPT: Pharmacometrics & Systems Pharmacology published by Wiley Periodicals, Inc. on behalf of the American Society for Clinical Pharmacology and Therapeutics.)

Purpose: Patients with open globe injuries routinely receive fluoroquinolone (FQ) prophylaxis to prevent bacterial infectious endophthalmitis. Owing to the rarity of this infection, there is an absence of clinical trials evaluating optimal prophylactic FQ dosing. To address this knowledge gap, we conducted a Monte Carlo simulation (MCS)-based study to identify the FQ dosing option(s) that optimize pharmacokinetic-pharmacodynamic FQ target attainment against common bacterial pathogens implicated in post-traumatic bacterial infectious endophthalmitis (PTBIE). Methods: Weighted mean pharmacokinetic parameters and standard deviations for ciprofloxacin, levofloxacin, and moxifloxacin were calculated from published studies in healthy volunteers. The incidence and FQ susceptibility profiles for the most common bacteria causing PTBIE were extracted from the literature. MCS was used to determine the cumulative fraction of response (CFR) for 5 FQ dosing options to determine the probability of attaining pathogen-specific target 24-hour area under the curve to minimum inhibitory concentration ratios in the vitreous humor of the eye against the 4 most common causative bacteria seen in PTBIE. Results: Moxifloxacin 400 mg po daily (M400) achieved the highest CFR (72%). Levofloxacin dosing options achieved CFRs between 54% and 63%. Ciprofloxacin dosing options achieved CFRs between 28% and 35%. Conclusion: M400 optimized the likelihood of prophylactic success in the prevention of PTBIE, and based on the study findings, M400 is predicted to optimize the probability of success compared with ciprofloxacin and levofloxacin dosing options currently endorsed by expert opinion.

Therapeutic drug monitoring (TDM) of moxifloxacin is recommended to improve the response to tuberculosis treatment and reduce acquired drug resistance. Limited sampling strategies (LSSs) are able to reduce the burden of TDM by using a small number of appropriately timed samples to estimate the parameter of interest, the area under the concentration-time curve. This study aimed to develop LSSs for moxifloxacin alone (MFX) and together with rifampin (MFX+RIF) in tuberculosis (TB) patients. Population pharmacokinetic (popPK) models were developed for MFX ( n  = 77) and MFX+RIF ( n  = 24). In addition, LSSs using Bayesian approach and multiple linear regression were developed. Jackknife analysis was used for internal validation of the popPK models and multiple linear regression LSSs. Clinically feasible LSSs (one to three samples, 6-h timespan postdose, and 1-h interval) were tested. Moxifloxacin exposure was slightly underestimated in the one-compartment models of MFX (mean -5.1%, standard error [SE] 0.8%) and MFX+RIF (mean -10%, SE 2.5%). The Bayesian LSSs for MFX and MFX+RIF (both 0 and 6 h) slightly underestimated drug exposure (MFX mean -4.8%, SE 1.3%; MFX+RIF mean -5.5%, SE 3.1%). The multiple linear regression LSS for MFX (0 and 4 h) and MFX+RIF (1 and 6 h), showed mean overestimations of 0.2% (SE 1.3%) and 0.9% (SE 2.1%), respectively. LSSs were successfully developed using the Bayesian approach (MFX and MFX+RIF; 0 and 6 h) and multiple linear regression (MFX, 0 and 4 h; MFX+RIF, 1 and 6 h). These LSSs can be implemented in clinical practice to facilitate TDM of moxifloxacin in TB patients., (Copyright © 2019 American Society for Microbiology.)

Fluoroquinolones are group A drugs in tuberculosis guidelines. We aim to compare the culture conversion between new-generation (levofloxacin and moxifloxacin) and old-generation (ciprofloxacin and ofloxacin) fluoroquinolones, develop pharmacokinetic models, and calculate target attainment for levofloxacin and moxifloxacin. We included three U.S. tuberculosis centers. Patients admitted between 1984 and 2015, infected with drug-resistant tuberculosis, and who had received fluoroquinolones for ≥28 days were included. Demographics, sputum cultures and susceptibility, treatment regimens, and serum concentrations were collected. A time-to-event analysis was conducted, and Cox proportional hazards model was used to compare the time to culture conversion. Using additional data from ongoing studies, pharmacokinetic modelling and Monte Carlo simulations were performed to assess target attainment for different doses. Overall, 124 patients received fluoroquinolones. The median age was 40 years, and the median weight was 60 kg. Fifty-six patients (45%) received old-generation fluoroquinolones. New-generation fluoroquinolones showed a faster time to culture conversion (median 16 versus 40 weeks, P  = 0.012). After adjusting for isoniazid and clofazimine treatment, patients treated with new-generation fluoroquinolones were more likely to have culture conversion (adjusted hazards ratio, 2.16 [95% confidence interval, 1.28 to 3.64]). We included 178 patients in the pharmacokinetic models. Levofloxacin and moxifloxacin were best described by a one-compartment model with first-order absorption and elimination. At least 1,500 to 1,750 mg levofloxacin and 800 mg moxifloxacin may be needed for maximum kill at the current epidemiologic cutoff values. In summary, new-generation fluoroquinolones showed faster time to culture conversion compared to the old generation. For optimal target attainment at the current MIC values, higher doses of levofloxacin and moxifloxacin may be needed., (Copyright © 2019 Al-Shaer et al.)

The pharmacokinetics, safety, and tolerability of a single dose of moxifloxacin were characterized in 31 pediatric patients already receiving antibiotics for a suspected or proven infection in an open-label phase 1 study. A dosing strategy for each age cohort (Cohort 1: ≥6 years to ≤14 years; Cohort 2: ≥2 years to <6 years; Cohort 3: >3 month to <2 years) was developed using physiology-based pharmacokinetic modeling combined with a stepwise dosing scheme to obtain a similar exposure to adults receiving 400 mg of moxifloxacin. Doses, adjusted to body weight and age, were gradually escalated from 5 mg/kg in Cohort 1 to 10 mg/kg in Cohort 3 based on interim analysis of the pharmacokinetic and safety data. Plasma and urine samples before and after the 60-minute infusion were collected for the analysis of moxifloxacin and its metabolites using a validated high-pressure liquid chromatography assay with tandem mass spectrometry. Moxifloxacin and metabolite concentrations in plasma were within the ranges observed in adults; however, clearance of all analytes was lower in pediatric patients compared with adults. Population pharmacokinetic analyses using the achieved exposure levels in the 3 age cohorts (with known body weight and clearance) predicted similar efficacy and safety profiles to adults. Moxifloxacin was well tolerated in all pediatric age cohorts. Adverse events related to moxifloxacin were mild or moderate in intensity and showed no correlation with increased weight-adjusted doses. Our findings guided the selection of age-appropriate clinical doses for a subsequent phase 3 clinical trial in pediatric patients with complicated intra-abdominal infections., (© 2019, The American College of Clinical Pharmacology.)

In this study, we evaluated a new aspect of negative pressure wound therapy (NPWT) as an analytical tool for pharmacokinetic studies. Twenty-one patients with soft tissue defects scheduled to receive NPWT were included in this study. Concomitant to NPWT, all patients received intravenous moxifloxacin (MX). At different time intervals, blood plasma levels of MX were sampled and compared with synchronous concentrations of MX in the exudate obtained from the NPWT drainage system. Serial measurements were performed upon initiation of the therapy as well as in the steady state (after 5 days). At steady state, wound tissue was obtained intraoperatively. High-performance liquid-chromatography (HPLC) was used for analysis. At 1 hour post-administration, the exudate/plasma levels (mg/L) were 1.92/3.07; at 12 hours, 0.80/1.14; at 24 hours, 0.26/0.43; and at 120 hours (steady state), 0.42/0.47. There was a correlation between exudate and plasma levels reaching approximately 0.75. Until now, methods for pharmacokinetic studies concerning interstitial fluid are difficult to apply in the clinical context. The presented method showed limitations, but we believe that, after methodological improvements, measurements of substances in the interstitial fluid by means of NPWT are feasible., (© 2019 Medicalhelplines.com Inc and John Wiley & Sons Ltd.)

This study aimed to evaluate the pharmacokinetic profile of moxifloxacin (MXF) in serum and sputum/bronchial secretions of 22 patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) hospitalized in the ward and intensive care unit (ICU). The data showed that ICU patients had lower concentrations in secretions ( P = 0.01). However, no other statistically significant differences were observed in pharmacokinetic parameters and penetration in secretions between ward and ICU patients. MXF showed a favorable pharmacokinetic profile, and the pharmacodynamic targets for common pathogens for AECOPD were achieved., (Copyright © 2019 American Society for Microbiology.)

Francisella tularensis causes a serious and often fatal infection, tularemia. We compared the efficacy of moxifloxacin formulated as free drug vs disulfide snap-top mesoporous silica nanoparticles (MSNs) in a mouse model of pneumonic tularemia. We found that MSN-formulated moxifloxacin was more effective than free drug and that the intramuscular and subcutaneous routes were markedly more effective than the intravenous route. Measurement of tissue silica levels and fluorescent flow cytometry assessment of colocalization of MSNs with infected cells revealed that the enhanced efficacy of MSNs and the intramuscular route of delivery was not due to better delivery of MSNs to infected tissues or cells. However, moxifloxacin blood levels demonstrated that the nanoparticle formulation and intramuscular route provided the longest half-life and longest time above the minimal inhibitory concentration. Thus, improved pharmacokinetics are responsible for the greater efficacy of nanoparticle formulation and intramuscular delivery compared with free drug and intravenous delivery.

A concurrent positive control should be included in a thorough QTc clinical trial to validate the study according to ICH E14 guidance. Some pharmaceutical companies have started to use "hybrid TQT" study to meet ICH E14 regulatory requirements since the release of ICH E14 Q&A (R3). The "hybrid TQT" study includes the same treatment arms (therapeutic and/or supratherapeutic dose of investigational drug, placebo, and positive control) with sample size less than traditional TQT studies, but use concentration-QTc (C-QTc) analysis as primary analysis and assay sensitivity analysis. To better understand the statistical characteristics of assay sensitivity with a commonly used positive control - Moxifloxacin - in "hybrid TQT" studies, we examined the original and subsampled moxifloxacin and placebo data from more than a hundred of TQT studies submitted to FDA. The assay sensitivity results are quite consistent between classical E14 analysis and C-QTc analysis using the original datasets. Performance of assay sensitivity in "hybrid TQT" studies using subsampled data depends on number of moxifloxacin subjects, study design (crossover design and parallel design), and C-QTc model. The results presented here can aid the design of future "hybrid TQT" studies.

Background: Children are often neglected during early development of antituberculosis agents, and most receive treatment after it is first tested in adults. However, very young children have tuberculosis that differs in many respects from adult cavitary pneumonia and could have different toxicity profiles to drugs. Linezolid is effective against intracellular tuberculosis, a common manifestation in young children. However, linezolid has considerable toxicity due to inhibition of mitochondrial enzymes. Tedizolid could be a replacement if it shows equal efficacy and reduced toxicity., Methods: We performed tedizolid dose-effect studies in the hollow fiber system model of intracellular tuberculosis. We measured linezolid concentrations, colony-forming units (CFU), time-to-positivity, and monocyte viability and performed RNA sequencing on infected cells collected from repetitive sampling of each system. We also compared efficacy of tedizolid vs linezolid and vs tedizolid-moxifloxacin combination., Results: There was no downregulation of mitochondrial enzyme genes, with a tedizolid 0-24 hour area under the concentration-time curve (AUC0-24) of up to 90 mg*h/L. Instead, high exposures led to increased mitochondrial gene expression and monocyte survival. The AUC0-24 to minimum inhibitory concentration ratio associated with 80% of maximal bacterial kill (EC80) was 184 by CFU/mL (r2 = 0.96) and 189 by time-to-positivity (r2 = 0.99). Tedizolid EC80 killed 4.0 log10 CFU/mL higher than linezolid EC80. The tedizolid-moxifloxacin combination had a bacterial burden elimination rate constant of 0.27 ± 0.05 per day., Conclusions: Tedizolid demonstrated better efficacy than linezolid, without the mitochondrial toxicity gene or cytotoxicity signatures encountered with linezolid. Tedizolid-moxifloxacin combination had a high bacterial elimination rate.

Chinfloxacin hydrochloride is a novel tricyclic fluorinated quinolone in development for treatment of conventional and biothreat infections. This first-in-human randomized study in Chinese healthy subjects was divided into 5 parts. Part A was a single-ascending-dose study to assess safety and tolerability of chinfloxacin. The single-dose pharmacokinetic study, a food effect study, and a multiple-dose pharmacokinetics study were conducted in parts B, C, and D, respectively. Part E was a randomized, placebo-controlled and positive-control single-dose, crossover study to evaluate the effect of chinfloxacin on thorough electrocardiographic QT/corrected QT (QTc) interval. The results suggest that single and multiple oral administrations of chinfloxacin were well tolerated. The observed adverse events (AEs) were dizziness, nausea, weakness, photosensitive dermatitis, and increased frequency of defecation. All AEs were mild and were resolved spontaneously without any treatment. The time to peak plasma concentration ( T max and C max , respectively) was about 2 h, and the half-life was 14 to 16 h. Food slightly affected the drug's rate and extent of absorption, increasing the T max from 1.60 to 2.59 h and reducing the C max by 13.6% and area under the concentration-time curve by 8.95%. Chinfloxacin at 400 mg had no effect on prolongation of QT/QTc intervals. Although 600 mg chinfloxacin had a mild effect on the prolongation of the QT/QTc interval, the effect was less pronounced than that of the positive control, 400 mg moxifloxacin. The pharmacokinetics and safety profiles of chinfloxacin in healthy Chinese volunteers support its once-daily dosing in future clinical investigations. (This study has been registered at www.ChiCTR.org.cn under identifiers ChiCTR-TRC-10001619 for parts A to D and ChiCTR1800015906 for part E.)., (Copyright © 2018 American Society for Microbiology.)

A major goal for improving tuberculosis therapy is to identify drug regimens with improved efficacy and shorter treatment durations. Shorter therapies improve patient adherence to the antibiotic regimens, which, in turn, decreases resistance emergence. Mycobacterium tuberculosis exists in multiple metabolic states. At the initiation of therapy, the bulk of the population is in log-phase growth. Consequently, it is logical to focus initial therapy on those organisms. Moxifloxacin has good early bactericidal activity against log-phase bacteria and is a logical component of initial therapy. It would be optimal if this agent also possessed activity against acid-phase and nonreplicative-persister (NRP) phenotype organisms. In our hollow-fiber infection model, we studied multiple exposures to moxifloxacin (equivalent to 200 mg to 800 mg daily) against strain H37Rv in the acid phase and against strain 18b in streptomycin starvation, which is a model for NRP-phase organisms. Moxifloxacin possesses good activity against acid-phase organisms, generating cell killing of 3.75 log 10 (CFU/ml) (200 mg daily) to 5.16 log 10 (CFU/ml) (800 mg daily) over the 28 days of the experiment. Moxifloxacin also has activity against streptomycin-starved strain 18b. The 400- to 800-mg daily regimens achieved extinction at day 28, while the no-treatment control still had 1.96 log 10 (CFU/ml) culturable. The lowest dose (200 mg daily) still had 0.7 log 10 (CFU/ml) measurable at day 28, a net kill of 1.26 log 10 (CFU/ml). Moxifloxacin is an attractive agent for early therapy, because it possesses activity against three metabolic states of M. tuberculosis ., (Copyright © 2018 American Society for Microbiology.)

Short-course regimens for multidrug-resistant tuberculosis (MDR-TB) are urgently needed. Limited data suggest that the new drug bedaquiline (BDQ) may have the potential to shorten MDR-TB treatment to less than 6 months when used in conjunction with standard anti-TB drugs. However, the feasibility of BDQ in shortening MDR-TB treatment duration remains to be established. Mathematical modeling provides a platform to investigate different treatment regimens and predict their efficacy. We developed a mathematical model to capture the immune response to TB inside a human host environment. This model was then combined with a pharmacokinetic-pharmacodynamic model to simulate various short-course BDQ-containing regimens. Our modeling suggests that BDQ could reduce MDR-TB treatment duration to just 18 weeks (4 months) while still maintaining a very high treatment success rate (100% for daily BDQ for 2 weeks, or 95% for daily BDQ for 1 week during the intensive phase). The estimated time to bacterial clearance of these regimens ranges from 27 to 33 days. Our findings provide the justification for empirical evaluation of short-course BDQ-containing regimens. If short-course BDQ-containing regimens are found to improve outcomes, then we anticipate clear cost savings and a subsequent improvement in the efficiency of national TB programs., (Copyright © 2018 American Society for Microbiology.)

Purpose: To determine the release profile of moxifloxacin encapsulated in liposomes in the aqueous humor as a controlled release system for intracameral application., Methods: Liposomes containing moxifloxacin were obtained using the lipid film hydration method and were characterized by particle size and encapsulation efficiency. Female rabbits were used for the in vivo profile release study. Liposomes containing moxifloxacin was injected into the anterior chamber of the right eye of each animal. The rabbits were divided into five groups, and a sample of aqueous humor was collected 2, 4, 8, 24, and 48 h after administration of liposomes containing moxifloxacin administration. Moxifloxacin concentrations in the aqueous humor were analyzed using high-performance liquid chromatography., Results: The average size of the liposomes containing moxifloxacin was 60.5 ± 0.72 nm with a particle size distribution of 0.307. The encapsulation efficiency of moxifloxacin in liposomes was 92.24 ± 0.24%. The results of an in vivo release study of liposomes containing moxifloxacin, showed that the maximum moxifloxacin concentration was achieved within the first 2 h after administration (5.27 ± 1.09 mg/mL) and was followed by a decrease in intracameral concentration (0.35 ± 0.05 mg/mL) until the 24 h mark., Conclusions: The in vivo experiments resulted in liposomes containing moxifloxacin that were homogenous in size and exhibited high drug encapsulation efficiency. The results indicate that liposomes containing moxifloxacin offers a satisfactory aqueous humor release profile after intracameral application.

Antimicrobial electrospun nonwoven Eudragit L-100 nanofibrous mats containing Moxifloxacin hydrochloride (MOX-HCL) were fabricated for fast dissolving drug delivery systems (DDSs) associated with wound infection. The morphological characterization of nanofibers using ESEM revealed that the average diameter of non-woven nanofibrous mats ranges 200-600 nm. The nanofiber showed cylindrical shape with crack on the surface. Differential scanning calorimetric (DSC) and Wide Angle X-ray diffraction (WAXRD) demonstrate that the drug exists in an amorphous state in the nanofibers. Nanofibrous mats were also tested for mechanical strength, contact angle, swelling assay, haemolysis and disintegration test. In vitro disintegration tests demonstrated that the dissolution of Eudragit L-100 fiber mats was within 25 s which was higher compared to the pure drug. The Eudragit nanofibers showed pH-dependent drug release profiles, with slow release at pH 1.2 and burst release (around 30 s) at pH 6.8. The in-vitro quantitative and qualitative antimicrobial assay showed that the developed Eudragit L-100 nanofibrous mats with MOX-HCL concentration of 1%, 5% and 15 wt% exhibited antibacterial activities against both gram positive (Staphylococcus aureus) and gram negative (Escherichia coli) bacteria. The in-vitro cytotoxicity assay using mouse fibroblast NIH/3T3 cells demonstrated significant biocompatibility of nanofiber mats. As per the results of biological evaluation, Eudragit L-100 nanofibrous mats with 1wt% MOX-HCL could be a suitable substrate for biomedical applications. Eudragit L-100 nanofibrous mats containing Moxifloxacin hydrochloride (MOX-HCL) showed immediate DDSs for localized drug release in the wound infection at slightly acidic or alkaline conditions where faster drug release rate is required for wound healing., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Objectives: To investigate the diffusion of moxifloxacin through bandage contact lenses (BCLs) versus corneal collagen shields (CSs), the relative ability of BCLs and CSs to release moxifloxacin, and the potential of release of moxifloxacin from CSs in the clinical setting., Methods: Using an in vitro model, the diffusion of 5% moxifloxacin across BCLs and CSs was compared. Next, the amount of drug release from BCLs and CSs soaked in 0.5% moxifloxacin was measured. Finally, based on a clinical model, CSs were soaked in Vigamox (commercial moxifloxacin) and the total concentration released was detected. Collagen shields remained intact after 24 hr; therefore, enzymatic digestion and mechanical grinding of the CS were performed to determine whether further drug could be released. The concentration of moxifloxacin was measured using a spectrophotometer at set time points up to 24 hr., Results: In the diffusion assay, 35.7±10.5% diffused through the BCLs and 36.2±11.8% diffused through the CSs (P=0.77). The absorption assay demonstrated at 120 min, a total of 33.3±6.77 μg/mL was released from BCLs compared with 45.8±5.2 μg/mL from the CSs (P=0.0008). In vitro experiments to simulate clinical application of Vigamox-soaked CS found the concentration of moxifloxacin released of 127.7±7.25 μg/mL in 2 mL of phosphate-buffered saline over 24 hr., Conclusions: Moxifloxacin diffuses through BCLs and CSs at similar rates; however, CSs have greater capacity to absorb and release moxifloxacin compared with BCLs. Vigamox-soaked CSs released 250 μg of moxifloxacin and may be a useful method to prevent endophthalmitis.