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Barone R, Conti M, Giorgi B, Gatti M, Cojutti PG, Viale P, Pea F. Fast and Sensitive Analysis of Fosfomycin in Human Plasma Microsamples Using Liquid Chromatography-Tandem Mass Spectrometry for Therapeutic Drug Monitoring. Ther Drug Monit 2024; 46:384-390. [PMID: 38018880 DOI: 10.1097/ftd.0000000000001158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Accepted: 08/09/2023] [Indexed: 11/30/2023]
Abstract
BACKGROUND Fosfomycin is an antibiotic recently repurposed as a potential combination treatment for difficult-to-treat Gram-negative bacterial infections. The pharmacokinetic features of fosfomycin have demonstrated that different pathophysiologic alterations may affect its exposure. Therapeutic drug monitoring may improve real-time management of fosfomycin therapy in different clinical scenarios. OBJECTIVES To develop and validate a fast and sensitive liquid chromatography - tandem mass spectrometry method for measuring fosfomycin in human plasma microsamples (3 µL). METHODS Analysis was preceded by a user-friendly pre-analytical single-step process performed via a rapid chromatographic run of 2.5 minutes, followed by negative electrospray ionization and detection on a high-sensitivity triple quadrupole tandem mass spectrometer operated in the multiple reaction monitoring mode. European Medicines Agency guidelines were used to validate the specificity, sensitivity, linearity, precision, accuracy, matrix effects, extraction recovery, limits of quantification, and stability of the analytical method. RESULTS The new assay produced accurate (BIAS%: 0.9-9.1) and precise (coefficient of variation [CV]%: 8.1-9.5) measurements of fosfomycin over a concentration range of 1-1000 mg/L. Overall, analyte recovery was consistent (mean values: 91.2%-97.2%) at all tested concentration levels. The analyte was also stable in human plasma and the final extract under various storage conditions. The clinical applicability of the assay was confirmed through quantitation of plasma samples obtained from patients. CONCLUSIONS A sensitive liquid chromatography - tandem mass spectrometry method for measuring fosfomycin in plasma was developed and validated according to the European Medicines Agency criteria. Quantitation of fosfomycin in clinical plasma samples confirmed that the assay is suitable for therapeutic drug monitoring in clinical scenarios.
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Affiliation(s)
- Rossella Barone
- Department of Medical and Surgical Sciences, Alma Mater Studiorum, University of Bologna, Bologna, Italy
| | - Matteo Conti
- Clinical Pharmacology Unit, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Bologna, Italy; and
| | - Beatrice Giorgi
- Clinical Pharmacology Unit, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Bologna, Italy; and
| | - Milo Gatti
- Department of Medical and Surgical Sciences, Alma Mater Studiorum, University of Bologna, Bologna, Italy
- Clinical Pharmacology Unit, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Bologna, Italy; and
| | - Pier Giorgio Cojutti
- Department of Medical and Surgical Sciences, Alma Mater Studiorum, University of Bologna, Bologna, Italy
- Clinical Pharmacology Unit, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Bologna, Italy; and
| | - Pierluigi Viale
- Department of Medical and Surgical Sciences, Alma Mater Studiorum, University of Bologna, Bologna, Italy
- Infectious Diseases Unit, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
| | - Federico Pea
- Department of Medical and Surgical Sciences, Alma Mater Studiorum, University of Bologna, Bologna, Italy
- Clinical Pharmacology Unit, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Bologna, Italy; and
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Optimizations of the Conditions for Ceftobiprole Determination in a Complex Matrix. Processes (Basel) 2022. [DOI: 10.3390/pr10112196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
A quick and accurate chromatographic–densitometric method for the determination of ceftobiprole in biological material (whole blood and urine) was developed. Preparation of the test sample required extraction of the drug from the matrix and was carried out by testing methanol or acetone as extracting agents, which were successfully used to isolate ceftobiprole from biological material. Under optimization of the procedure, various stationary and mobile phases were tested. Lastly, HPTLC cellulose plates and a mixture containing ethanol, 2-propanol, glacial acetic acid, and water in the ratio 4:4:1:3 (v/v/v/v) were chosen. Densitometric detection was made at a maximum absorbance of 316 nm. The developed method was validated; a linear function of the ceftobiprole concentration was obtained in the range of 2.4–72 µg/mL (r > 0.99) for both methanol and acetone solutions. The average accuracy of the devised method was measured at nearly 100%; nevertheless, the limit of the quantification was at 8.92 for methanol and 9.14 µg/mL for acetone solution. Therefore, the above method can be successfully used to ceftobiprole in biological material.
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Concepts for New Rapid Simple HPLC Method for Quantification of Fosfomycin Trometamol in Pharmaceutical Dosage Forms with Direct UV Detection. Sci Pharm 2022. [DOI: 10.3390/scipharm90020035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Two different concepts for developing direct HPLC-UV methods for quantifying fosfomycin trometamol were developed without any derivatization and modification of the analyte. In the first concept, without the use of alkylamines as ion-pairs in the mobile phase, by using cyanopropyl CN and a strong anion-exchanger column, we investigated the possibility of their highly polar and anion-exchanging forces and mechanisms to retain, separate and detect trometamol without the help of additional agents or modifiers. In the second concept, the most frequent reversed-phase C18 columns with different characteristics and vendors were tested in combination with different length-based alkylamines with 3–10 C atoms in their chains. In our research, we found that the ion-pairing of fosfomycin with 6–10 C-atom-based alkyl-length of aliphatic chains manifested the most appropriate strength of interactions between alkyl-paired trometamol molecules and octadecylsilane or C18 bonded RP column to achieve optimal retention, selectivity and peak shape on chromatograms, with the possibility for the fine-tuning of elution time. The simplicity of our method concept omits the need for expensive and sophisticated columns like HILIC, C30 graphite carbon, and mixed-mode-based columns for easier retaining, separation, and determination of fosfomycin, and for its quantification purposes, especially in high-throughput analyses in regular quality-control laboratories.
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High-Dosage Fosfomycin Results in Adequate Plasma and Target-Site Exposure in Morbidly Obese and Nonobese Nonhyperfiltration Patients. Antimicrob Agents Chemother 2022; 66:e0230221. [PMID: 35603536 DOI: 10.1128/aac.02302-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The objectives of this study were the identification in (morbidly) obese and nonobese patients of (i) the most appropriate body size descriptor for fosfomycin dose adjustments and (ii) adequacy of the currently employed dosing regimens. Plasma and target site (interstitial fluid of subcutaneous adipose tissue) concentrations after fosfomycin administration (8 g) to 30 surgery patients (15 obese/15 nonobese) were obtained from a prospective clinical trial. After characterization of plasma and microdialysis-derived target site pharmacokinetics via population analysis, short-term infusions of fosfomycin 3 to 4 times daily were simulated. The adequacy of therapy was assessed by probability of pharmacokinetic/pharmacodynamic target attainment (PTA) analysis based on the unbound drug-related targets of an %fT>MIC (the fraction of time that unbound fosfomycin concentrations exceed the MIC during 24 h) of 70 and an fAUC0-24h/MIC (the area under the concentration-time curve from 0 to 24 h for the unbound fraction of fosfomycin relative to the MIC) of 40.8 to 83.3. Lean body weight, fat mass, and creatinine clearance calculated via adjusted body weight (ABW) (CLCRCG_ABW) of all patients (body mass index [BMI] = 20.1 to 52.0 kg/m2) explained a considerable proportion of between-patient pharmacokinetic variability (up to 31.0% relative reduction). The steady-state unbound target site/plasma concentration ratio was 26.3% lower in (morbidly) obese than nonobese patients. For infections with fosfomycin-susceptible pathogens (MIC ≤ 16 mg/L), intermittent "high-dosage" intravenous (i.v.) fosfomycin (8 g, three times daily) was sufficient to treat patients with a CLCRCG_ABW of <130 mL/min, irrespective of the pharmacokinetic/pharmacodynamic indices considered. For infections by Pseudomonas aeruginosa with a MIC of 32 mg/L, when the index fAUC0-24h/MIC is applied, fosfomycin might represent a promising treatment option in obese and nonobese patients, especially in combination therapy to complement β-lactams, in which carbapenem-resistant P. aeruginosa is critical. In conclusion, fosfomycin showed excellent target site penetration in obese and nonobese patients. Dosing should be guided by renal function rather than obesity status. (This study has been registered in the EU Clinical Trials Register under EudraCT no. 2012-004383-22.).
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Goh KKK, Toh WGH, Hee DKH, Ting EZW, Chua NGS, Zulkifli FIB, Sin LJ, Tan TT, Kwa ALH, Lim TP. Quantification of Fosfomycin in Combination with Nine Antibiotics in Human Plasma and Cation-Adjusted Mueller-Hinton II Broth via LCMS. Antibiotics (Basel) 2022; 11:antibiotics11010054. [PMID: 35052932 PMCID: PMC8772704 DOI: 10.3390/antibiotics11010054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 12/28/2021] [Accepted: 12/29/2021] [Indexed: 02/05/2023] Open
Abstract
Fosfomycin-based combination therapy has emerged as an attractive option in our armamentarium due to its synergistic activity against carbapenem-resistant Gram-negative bacteria (CRGNB). The ability to simultaneously measure fosfomycin and other antibiotic drug levels will support in vitro and clinical investigations to develop rational antibiotic combination dosing regimens against CRGNB infections. We developed an analytical assay to measure fosfomycin with nine important antibiotics in human plasma and cation-adjusted Mueller–Hinton II broth (CAMHB). We employed a liquid-chromatography tandem mass spectrometry method and validated the method based on accuracy, precision, matrix effect, limit-of-detection, limit-of-quantification, specificity, carryover, and short-term and long-term stability on U.S. Food & Drug Administration (FDA) guidelines. Assay feasibility was assessed in a pilot clinical study in four patients on antibiotic combination therapy. Simultaneous quantification of fosfomycin, levofloxacin, meropenem, doripenem, aztreonam, piperacillin/tazobactam, ceftolozane/tazobactam, ceftazidime/avibactam, cefepime, and tigecycline in plasma and CAMHB were achieved within 4.5 min. Precision, accuracy, specificity, and carryover were within FDA guidelines. Fosfomycin combined with any of the nine antibiotics were stable in plasma and CAMHB up to 4 weeks at −80 °C. The assay identified and quantified the respective antibiotics administered in the four subjects. Our assay can be a valuable tool for in vitro and clinical applications.
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Affiliation(s)
- Kelvin Kau-Kiat Goh
- Department of Pharmacy, Singapore General Hospital, Outram Road, Singapore 169608, Singapore; (K.K.-K.G.); (W.G.-H.T.); (N.G.S.C.); (F.I.B.Z.); (L.-J.S.)
- SingHealth Duke-NUS Pathology Academic Clinical Programme, 8 College Road, Singapore 169857, Singapore
| | - Wilson Ghim-Hon Toh
- Department of Pharmacy, Singapore General Hospital, Outram Road, Singapore 169608, Singapore; (K.K.-K.G.); (W.G.-H.T.); (N.G.S.C.); (F.I.B.Z.); (L.-J.S.)
| | - Daryl Kim-Hor Hee
- Shimadzu (Asia Pacific) Pte Ltd., 79 Science Park Dr, #02-01/08 Cintech IV, Singapore 118264, Singapore; (E.Z.-W.T.); (D.K.-H.H.)
| | - Edwin Zhi-Wei Ting
- Shimadzu (Asia Pacific) Pte Ltd., 79 Science Park Dr, #02-01/08 Cintech IV, Singapore 118264, Singapore; (E.Z.-W.T.); (D.K.-H.H.)
| | - Nathalie Grace Sy Chua
- Department of Pharmacy, Singapore General Hospital, Outram Road, Singapore 169608, Singapore; (K.K.-K.G.); (W.G.-H.T.); (N.G.S.C.); (F.I.B.Z.); (L.-J.S.)
| | - Farah Iffah Binte Zulkifli
- Department of Pharmacy, Singapore General Hospital, Outram Road, Singapore 169608, Singapore; (K.K.-K.G.); (W.G.-H.T.); (N.G.S.C.); (F.I.B.Z.); (L.-J.S.)
| | - Li-Jiao Sin
- Department of Pharmacy, Singapore General Hospital, Outram Road, Singapore 169608, Singapore; (K.K.-K.G.); (W.G.-H.T.); (N.G.S.C.); (F.I.B.Z.); (L.-J.S.)
| | - Thuan-Tong Tan
- SingHealth Duke-NUS Medicine Academic Clinical Programme, 8 College Road, Singapore 169857, Singapore;
- Department of Infectious Diseases, Singapore General Hospital, Outram Road, Singapore 169608, Singapore
| | - Andrea Lay-Hoon Kwa
- Department of Pharmacy, Singapore General Hospital, Outram Road, Singapore 169608, Singapore; (K.K.-K.G.); (W.G.-H.T.); (N.G.S.C.); (F.I.B.Z.); (L.-J.S.)
- SingHealth Duke-NUS Medicine Academic Clinical Programme, 8 College Road, Singapore 169857, Singapore;
- Emerging Infectious Diseases Program, Duke-NUS Medical School, 8 College Road, Singapore 169857, Singapore
- Correspondence: (A.L.-H.K.); (T.-P.L.); Tel.: +65-6321-3401 (A.L.-H.K.); +65-6326-6959 (T.-P.L.)
| | - Tze-Peng Lim
- Department of Pharmacy, Singapore General Hospital, Outram Road, Singapore 169608, Singapore; (K.K.-K.G.); (W.G.-H.T.); (N.G.S.C.); (F.I.B.Z.); (L.-J.S.)
- SingHealth Duke-NUS Pathology Academic Clinical Programme, 8 College Road, Singapore 169857, Singapore
- SingHealth Duke-NUS Medicine Academic Clinical Programme, 8 College Road, Singapore 169857, Singapore;
- Correspondence: (A.L.-H.K.); (T.-P.L.); Tel.: +65-6321-3401 (A.L.-H.K.); +65-6326-6959 (T.-P.L.)
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Baldelli S, Cerea M, Mangioni D, Alagna L, Muscatello A, Bandera A, Cattaneo D. Fosfomycin therapeutic drug monitoring in real-life: development and validation of a LC-MS/MS method on plasma samples. J Chemother 2021; 34:25-34. [PMID: 34410896 DOI: 10.1080/1120009x.2021.1963617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Individualization of fosfomycin dosing based on therapeutic drug monitoring (TDM) of plasma concentrations could reduce drug-related adverse events and improve clinical outcome in complex clinical conditions. Quantification of fosfomycin in plasma samples was performed by a rapid ultraperformance liquid chromatography mass spectrometry method. Sample preparation involved protein precipitation with [13C3]-fosfomycin benzylamine salt as internal standard. The calibration curve ranged from 2 to 800 mg/L. Within- and between-day precision and accuracy, sensitivity, selectivity, dilution integrity, recovery were investigated and the results met the acceptance criteria. In patients, multiple drug dosing (every 6 or 8 hours) or in continuous administration were adopted, resulting in a large interpatient variability in drug concentrations (from 7.4 mg/L and 644.6 mg/L; CV: 91.1%). In critical care patient setting TDM can represent an important tool to identify the best fosfomycin dosing in single patients, taking into consideration clinical characteristics, infection sites and susceptibility of the treated pathogens.
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Affiliation(s)
- Sara Baldelli
- Unit of Clinical Pharmacology, L. Sacco University Hospital, Milano, Italy
| | - Matteo Cerea
- Department of Pharmaceutical Sciences, Università degli Studi di Milano, Milan, Italy
| | - Davide Mangioni
- Infectious Diseases Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.,Department of Medical Biotechnology and Translational Medicine, Università di Milano, Milan, Italy
| | - Laura Alagna
- Infectious Diseases Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Antonio Muscatello
- Infectious Diseases Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Alessandra Bandera
- Infectious Diseases Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.,Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Milan, Italy
| | - Dario Cattaneo
- Unit of Clinical Pharmacology, L. Sacco University Hospital, Milano, Italy
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Plasma and tissue pharmacokinetics of fosfomycin in morbidly obese and non-obese surgical patients: a controlled clinical trial. J Antimicrob Chemother 2019; 74:2335-2340. [DOI: 10.1093/jac/dkz203] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 04/04/2019] [Accepted: 04/09/2019] [Indexed: 01/10/2023] Open
Abstract
Abstract
Objectives
To assess the pharmacokinetics and tissue penetration of fosfomycin in obese and non-obese surgical patients.
Methods
Fifteen obese patients undergoing bariatric surgery and 15 non-obese patients undergoing major intra-abdominal surgery received an intravenous single short infusion of 8 g of fosfomycin. Fosfomycin concentrations were determined by LC-MS/MS in plasma and microdialysate from subcutaneous tissue up to 8 h after dosing. The pharmacokinetic analysis was performed in plasma and interstitial fluid (ISF) by non-compartmental methods.
Results
Thirteen obese patients (BMI 38–50 kg/m2) and 14 non-obese patients (BMI 0–29 kg/m2) were evaluable. The pharmacokinetics of fosfomycin in obese versus non-obese patients were characterized by lower peak plasma concentrations (468 ± 139 versus 594 ± 149 mg/L, P = 0.040) and higher V (24.4 ± 6.4 versus 19.0 ± 3.1 L, P = 0.010). The differences in AUC∞ were not significant (1275 ± 477 versus 1515 ± 352 mg·h/L, P = 0.16). The peak concentrations in subcutaneous tissue were reached rapidly and declined in parallel with the plasma concentrations. The drug exposure in tissue was nearly halved in obese compared with non-obese patients (AUC∞ 1052 ± 394 versus 1929 ± 725 mg·h/L, P = 0.0010). The tissue/plasma ratio (AUCISF/AUCplasma) was 0.86 ± 0.32 versus 1.27 ± 0.34 (P = 0.0047).
Conclusions
Whereas the pharmacokinetics of fosfomycin in plasma of surgical patients were only marginally different between obese and non-obese patients, the drug exposure in subcutaneous tissue was significantly lower in the obese patients.
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Hösl J, Gessner A, El-Najjar N. Liquid chromatography-tandem mass spectrometry for the quantification of moxifloxacin, ciprofloxacin, daptomycin, caspofungin, and isavuconazole in human plasma. J Pharm Biomed Anal 2018; 157:92-99. [PMID: 29777985 DOI: 10.1016/j.jpba.2018.05.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Revised: 05/04/2018] [Accepted: 05/11/2018] [Indexed: 01/20/2023]
Abstract
A simple and precise ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed for the simultaneous analysis of five anti-infective agents used to treat severe infections [three antibiotics (daptomycin, moxifloxacin, ciprofloxacin) and two antifungals (isavuconazole, caspofungin)] in human plasma. Sample preparation was based on protein precipitation with ice cold methanol. All five agents were analyzed with the corresponding isotopically labeled internal standards. All analytes were detected in multiple reactions monitoring (MRM) using API 4000 triple-quadrupole mass spectrometer with electrospray (ESI) source operating in positive mode. The calibration curves were linear over the selected ranges (r > 0.99). The method is precise and accurate with a total run time of 5.5 min. Accuracy of all target analytes ranged between 95.9-116.6%, measured with an imprecision of less than 10.8%. The lower limit of quantification was 1.25 mg/L for caspofungin, 0.3125 mg/L for isavuconazole, 3.125 mg/L for daptomycin, 0.075 mg/L for ciprofloxacin, and 0.1875 mg/L for moxifloxacin. The successful application of the method in patient samples proved its suitability for the medical surveillance of antimicrobial therapy in intensive care units as well as to other pharmacokinetic studies.
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Affiliation(s)
- Julian Hösl
- Institute of Clinical Microbiology and Hygiene, University Hospital Regensburg, Regensburg, Germany
| | - André Gessner
- Institute of Clinical Microbiology and Hygiene, University Hospital Regensburg, Regensburg, Germany.
| | - Nahed El-Najjar
- Institute of Clinical Microbiology and Hygiene, University Hospital Regensburg, Regensburg, Germany; Institute of Clinical Chemistry and Laboratory Medicine, University Hospital Regensburg, Regensburg, Germany.
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Gandhi A, Matta M, Garimella N, Zere T, Weaver J. Development and validation of a LC-MS/MS method for quantitation of fosfomycin - Application to in vitro antimicrobial resistance study using hollow-fiber infection model. Biomed Chromatogr 2018; 32:e4214. [PMID: 29461629 DOI: 10.1002/bmc.4214] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 01/31/2018] [Accepted: 02/09/2018] [Indexed: 11/05/2022]
Abstract
Extensive use and misuse of antibiotics over the past 50 years has contributed to the emergence and spread of antibiotic-resistant bacterial strains, rendering them as a global health concern. To address this issue, a dynamic in vitro hollow-fiber system, which mimics the in vivo environment more closely than the static model, was used to study the emergence of bacterial resistance of Escherichia coli against fosfomycin (FOS). To aid in this endeavor we developed and validated a liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay for quantitative analysis of FOS in lysogeny broth. FOS was resolved on a Kinetex HILIC (2.1 × 50 mm, 2.6 μm) column with 2 mm ammonium acetate (pH 4.76) and acetonitrile as mobile phase within 3 min. Multiple reaction monitoring was used to acquire data on a triple quadrupole mass spectrometer. The assay was linear from 1 to 1000 μg/mL. Inter- and intra-assay precision and accuracy were <15% and between ±85 and 115% respectively. No significant matrix effect was observed when corrected with the internal standard. FOS was stable for up to 24 h at room temperature, up to three freeze-thaw cycles and up to 24 h when stored at 4°C in the autosampler. In vitro experimental data were similar to the simulated plasma pharmacokinetic data, further confirming the appropriateness of the experimental design to quantitate antibiotics and study occurrence of antimicrobial resistance in real time. The validated LC-MS/MS assays for quantitative determination of FOS in lysogeny broth will help antimicrobial drug resistance studies.
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Affiliation(s)
- Adarsh Gandhi
- Division of Applied Regulatory Science, Office of Clinical Pharmacology, Food and Drug Administration, Silver Spring, Maryland, USA
| | - Murali Matta
- Division of Applied Regulatory Science, Office of Clinical Pharmacology, Food and Drug Administration, Silver Spring, Maryland, USA
| | - Narayana Garimella
- Division of Applied Regulatory Science, Office of Clinical Pharmacology, Food and Drug Administration, Silver Spring, Maryland, USA
| | - Tesfalem Zere
- Division of Applied Regulatory Science, Office of Clinical Pharmacology, Food and Drug Administration, Silver Spring, Maryland, USA
| | - James Weaver
- Division of Applied Regulatory Science, Office of Clinical Pharmacology, Food and Drug Administration, Silver Spring, Maryland, USA
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