A new simple HPLC assay for the quantification of ertapenem in human plasma, lung tissue, and broncho-alveolar lavage fluid

HPLC/UV approach method for the first simultaneous estimation of molnupiravir and ertapenem as a binary mixture in human plasma and dosage form as a regimen for COVID-19 treatments

COVID-19 is a serious virus that can have a lot of effects, one of which is a secondary bacterial infection that can be more life-threatening and even lethal than the initial viral infection. Hence a fast and sensitive HPLC/UV method was developed and validated for the first estimation of a binary mixture of molnupiravir (MOL) and ertapenem (ERT) as a co-administrated medicine for the management of COVID-19 in pharmaceutical dosage forms, and human plasma samples. The drug combination was separated within 5 min via RP-ODS column using isocratic elution with a mobile phase of 0.05 M phosphate buffer (pH 3.5): acetonitrile with a 76: 24% ratio v/v. The presented method provided a linear response ranging from 0.03 to 17.0 and 0.05-20 µg mL-1 with LOD values of 0.009 and 0.008 µg mL-1 for MOL and ERT respectively. The good separation and high sensitivity of the HPLC method provide the determination of the cited drugs in human plasma without matrix interference with a percent of recovery ranging from 94.97 ± 2.05 to 98.44 ± 1.92. Based on the results, this method could be utilized to monitor cited drugs in quality control and therapeutic laboratories.

Methods for Determination of Meropenem Concentration in Biological Samples

Measuring the concentration of antibiotics in biological samples allow implementation of therapeutic monitoring of these drugs and contribute to the adjustment of the dosing regimen in patients. This increases the effectiveness of antimicrobial therapy, reduces the toxicity of these drugs and prevents the development of bacterial resistance. This review article summarizes current knowledge on methods for determining concentration of meropenem, an antibiotic drug from the group of carbapenems, in different biological samples. It provides a brief discussion of the chemical structure, physicochemical and pharmacokinetic properties of meropenem, different sample preparation techniques, use of apparatus and equipment, knowledge of the advantages and limitations of available methods, as well as directions in which new methods should be developed. This review should facilitate clinical laboratories to select and apply one of the established methods for measuring of meropenem, as well as to provide them with the necessary knowledge to develop new methods for quantification of meropenem in biological samples according to their needs.

Plasma and intraprostatic concentrations of ertapenem following preoperative single dose administration: a single-centre prospective experience and clinical implications-the ERTAPRO study

The incidence of urinary tract infections caused by extended-spectrum β-lactamase (ESBL)-producing pathogens is increasing. These infections are associated with a long hospital stay in patients undergoing urological procedures. We aimed to demonstrate that significant intraprostatic diffusion of ertapenem is achieved after a single preoperative administration. A referred sample of 19 patients requiring surgery for benign prostatic hyperplasia was prospectively included. Patients received a 1 g intravenous (i.v.) dose of ertapenem 1 h (n = 10, group A) or 12 h (n = 9, group B) before blood and prostatic samples were collected. Plasma and intraprostatic concentrations of ertapenem were measured using LC-MS/MS. Intraprostatic concentrations were considered satisfactory when higher than the MIC90 value of urinary-targeted pathogens perioperatively and for 40% of the dosing interval. The Wilcoxon test and a pharmacokinetic predictive model were used. Median plasma concentrations of ertapenem were 144.3 mg/L (95% CI 126.5-157.9) in group A and 30.7 mg/L (95% CI 22.9-36.4) in group B (P < 0.001); median intraprostatic concentrations were 16.6 mg/L (95% CI 13.3-31.4 mg/L) and 4.2 mg/L (95% CI 3.1-4.9 mg/L), respectively (P < 0.001), which were above the MIC90 values of bacteria, including ESBL-producers, during surgery and for 40% of the dosing interval. The plasma-to-prostate concentration ratio was not significantly different between groups (P = 0.97). Single-dose i.v. ertapenem reached satisfactory intraprostatic concentrations, suggesting that it could be a relevant prophylactic strategy for carriers of ESBL-producing bacteria undergoing prostatic procedures, which needs to be confirmed by further prospective trials.

Quantification and validation of HPLC-UV and LC-MS assays for therapeutic drug monitoring of ertapenem in human plasma

Rapid and simple HPLC-UV and LC-MS methods were developed and validated for the quantification of ertapenem (Invanz™) in human plasma. Ertapenem is a unique drug in that current dosing recommendations call for a 1 g dose for normal renal function patients, despite body weight. These assays, which involve a protein precipitation followed by liquid-liquid extraction, allow for fast therapeutic drug monitoring of ertapenem in patients, which is especially useful in special populations. Both methods were sufficient to baseline resolve meropenem (internal standard) and ertapenem, and were validated over 3 days using a six-point calibration curve (0.5-50 µg/mL). Validation was collected using four different points on the calibrations curve yielding acceptable precision (<15% inter-day and intra-day; <20% for lower limit of quantitation, LLOQ) as well as accuracy (<15% inter-day and intra-day; <20% for LLOQ). The lower limit of detection (LOD) was determined to be 0.1 and 0.05 µg/mL for the HPLC-UV and LC-MS methods, respectively. The developed HPLC-UV and LC-MS methods for ertapenem quantification are fast, accurate and reproducible over the calibration range and can be used to determine ertapenem plasma concentrations for monitoring clinical efficacy.

A liquid chromatography assay for a quantification of doripenem, ertapenem, imipenem, meropenem concentrations in human plasma: application to a clinical pharmacokinetic study

A simple chromatographic assay based on ultra high performance liquid chromatography with ultraviolet detection at 295 nm is proposed to determinate simultaneously human plasma concentrations of imipenem, doripenem, meropenem and ertapenem. After deproteinization by acetonitrile, carbapenems are separated on a PentaFluoroPhenyl column with a binary gradient elution. This method is specific, accurate, precise (the intra-day and inter-day imprecision and inaccuracy are lower than 15%), sensitive (the limit of quantitation is equal to 0.50 mg/L for imipenem, doripenem, ertapenem, meropenem) and not time consuming (run time=7 min). An application of this method to measure ertapenem plasma concentrations in burn patients is presented.

Selective determination of ertapenem in the presence of its degradation product

Stability-indicative determination of ertapenem (ERTM) in the presence of its beta-lactam open-ring degradation product, which is also the metabolite, is investigated. The degradation product has been isolated, via acid-degradation, characterized and elucidated. Selective quantification of ERTM, singly in bulk form, pharmaceutical formulations and/or in the presence of its major degradant is demonstrated. The indication of stability has been undertaken under conditions likely to be expected at normal storage conditions. Among the spectrophotometric methods adopted for quantification are first derivative ((1)D), first derivative of ratio spectra ((1)DD) and bivariate analysis.