Objective: To establish an LC-MS/MS method for determining the concentrations of imipenem and cilastatin in human plasma, for monitoring clinical therapeutic drug concentrations, and to investigate the effects of adding stabilizers during the sample pretreatment on mass spectrometry signal intensity. Methods: After protein precipitation, the sample was subjected to gradient elution using an Agilent TC-C18 (2) (150 mm×4.6 mm, 5 µm) column with a mobile phase system of 0.15% formic acid in water and methanol. The electrospray ionization (ESI) mass spectrometer was operated in positive ion mode using multiple reaction monitoring (MRM): m/z 300.1 → 141.9 (imipenem),m/z 359.7 → 97.0 (cilastatin) and m/z 384.1 → 141.1 (meropenem, internal standard). The samples containing and without 3-(N-morpholino) propane sulfonic acid (MOPS) as stabilizers were pretreated and continuously analyzed to compare the changes in mass spectrometry signal intensity. Results: Both imipenem and cilastatin showed good linearities in the concentration ranges of 0.1-100.0 μg · mL-1 (r>0.99). The intra-day and inter-day accuracy ranges from 95.3% to 108.5%, the precision (RSDs) were less than 9.3%, the extraction recovery rate ranges from 77.4% to 84.3%, and the matrix effect ranges from 97.1% to 111.2%. Imipenem in plasma samples was stable at room temperature for 3 h, at 4 ℃ for 6 h, and at -80 ℃ for 12 d, while it was significantly degraded at -20 ℃ for 12 d. Cilastatin was stable under a variety of conditions. The method was robust to changing conditions of column temperature ±5 ℃, flow rate ±0.1 mL · min-1, formic acid concentration in the aqueous phase ±0.025%, and ion source temperature ±50 ℃. The samples containing stabilizers exhibited significant ion inhibition on mass spectrometry after continuous injection, while samples without stabilizers had no significant effect on the signal intensity of mass spectrometry. Conclusion: The method is simple and accurate and can be used for clinical drug monitoring of imipenem and cilastatin. Nonvolatile salt stabilizers such as MOPS can reduce mass spectrometry sensitivity, and the absence of such stabilizers is more suitable for long-term analysis by LC-MS/MS.
[1] ZHANEL GG,WIEBE R,DILAY L,et al.Comparative review of the carbapenems[J].Drugs,2007,67(7):1027
[2] GUILHAUMOU R,BENABOUD S,BENNIS Y,et al.Optimization of the treatment with beta-lactam antibiotics in critically ill patients-guidelines from the French Society of Pharmacology and Therapeutics(Société Francaise de Pharmacologie et Thérapeutique-SFPT)and the French Society of Anaesthesia and Intensive Care Medicine(Société Francaise d’Anesthésie et Réanimation-SFAR)[J].Crit Care,2019,23(1):104
[3] BELZBERG H,ZHU J,CORNWELL EE,et al.Imipenem levels are not predictable in the critically ill patient[J].J Trauma,2004,56(1):111
[4] RODLOFF AC,GOLDSTEIN EJ,TORRES A.Two decades of imipenem therapy[J].J Antimicrob Chemother,2006,58(5):916
[5] SHAYAN M,ELYASI S.Cilastatin as a protective agent against drug-induced nephrotoxicity:a literature review[J].Expert Opin Drug Saf,2020,19(8):999
[6] GONZÁLEZ-NICOLÁS MÁ,LÁZARO A.Cilastatin,a new therapeutic promise for acute kidney injury[J].Kidney Int,2024,106(4):560
[7] 邓阳,徐兵,李昕,等.基于亚胺培南稳定性考察的治疗药物监测临床采样流程建立[J].中国临床药理学杂志,2018,34(18):2207
DENG Y,XU B,LI X,et al.Stablishing the clinical sampling process of therapeutic drug monitoring based on stability of imipenem[J].Chin J Clin Pharmacol,2018,34(18):2207
[8] ZOU L,MENG F,HU L,et al.A novel reversed-phase high-performance liquid chromatographic assay for the simultaneous determination of imipenem and meropenem in human plasma and its application in TDM[J].J Pharm Biomed Anal,2019,169:142
[9] DAILLY E,BOUQUIÉ R,DESLANDES G,et al.A liquid chromatography assay for a quantification of doripenem,ertapenem,imipenem,meropenem concentrations in human plasma:application to a clinical pharmacokinetic study[J].J Chromatogr B Analyt Technol Biomed Life Sci,2011,879(15-16):1137
[10] LÓPEZ KJ,BERTOLUCI DF,VICENTE KM,et al.Simultaneous determination of cefepime,vancomycin and imipenem in human plasma of burn patients by high-performance liquid chromatography[J].J Chromatogr B Analyt Technol Biomed Life Sci,2007,860(2):241
[11] 冯章英,邢冬,李斌,等.UPLC-MS/MS法测定人血浆中亚胺培南浓度[J].药物分析杂志,2017,37(11):2076
FENG ZY,XING D,LI B,et al.Determination of imipenem in human plasma by UPLC-MS/MS method[J].Chin J Pharm Anal,2017,37(11):2076
[12] 王晓雪,陈文清,孔旭东,等.人血浆中亚胺培南和美罗培南的UPLC-MS/MS分析方法建立及治疗药物监测[J].中国药学杂志,2018,53(3):218
WANG XX,CHEN WQ,KONG XD,et al.Quantification of imipenem and meropenem in human plasma by UPLC-MS /MS and its application in therapeutic drug monitoring[J].Chin Pharm J,2018,53(3):218
[13] REHM S,RENTSCH KM.HILIC LC-MS/MS method for the quantification of cefepime,imipenem and meropenem[J].J Pharm Biomed Anal,2020,186:113289
[14] HU ZY,BOUCHER BA,LAIZURE SC,et al.Nonvolatile salt-free stabilizer for the quantification of polar imipenem and cilastatin in human plasma using hydrophilic interaction chromatography/quadrupole mass spectrometry with contamination sensitive off-axis electrospray[J].J Mass Spectrom,2013,48(8):945
[15] ABDULLA A,BAHMANY S,WIJMA RA,et al.Simultaneous determination of nine beta-lactam antibiotics in human plasma by an ultrafast hydrophilic-interaction chromatography-tandem mass spectrometry[J].J Chromatogr B Analyt Technol Biomed Life Sci,2017,1060:138
[16] XU Y,XIE W,MILLER-STEIN CM,et al.Hydrophilic interaction chromatography/tandem mass spectrometry for the simultaneous determination of three polar non-structurally related compounds,imipenem,cilastatin and an investigational beta-lactamase inhibitor,MK-4698,in biological matrices[J].Rapid Commun Mass Spectrom,2009,23(14):2195
[17] BAHMANY S,ABDULLA A,EWOLDT TMJ,et al.High-throughput analysis for the simultaneous quantification of nine beta-lactam antibiotics in human plasma by UPC 2-MS/MS:method development,validation,and clinical application[J].J Pharm Biomed Anal,2022,219:114904
[18] DE SOUZA BARBOSA F,CAPRA PEZZI L,TSAO M,et al.Stability and degradation products of imipenem applying high-resolution mass spectrometry:an analytical study focused on solutions for infusion[J].Biomed Chromatogr,2019,33(4):e4471
[19] LEFEUVRE S,BOIS-MAUBLANC J,HOCQUELOUX L,et al.A simple ultra-high-performance liquid chromatography-high resolution mass spectrometry assay for the simultaneous quantification of 15 antibiotics in plasma[J].J Chromatogr B Analyt Technol Biomed Life Sci,2017,1065-1066:50
[20] FISH DN,TEITELBAUM I,ABRAHAM E.Pharmacokinetics and pharmacodynamics of imipenem during continuous renal replacement therapy in critically ill patients[J].Antimicrob Agents Chemother,2005,49(6):2421
[21] LI Z,BAI J,WEN A,et al.Pharmacokinetic and pharmacodynamic analysis of critically ill patients undergoing continuous renal replacement therapy with imipenem[J].Clin Ther,2020,42(8):1564
[22] COTTON A,FRANKLIN BD,BRETT S,et al.Using imipenem and cilastatin during continuous renal replacement therapy[J].Pharm World Sci,2005,27(5):371
