Monitoring of amoxicilline and ceftazidime in the microdialysate of diabetic foot and serum by capillary electrophoresis with contactless conductivity detection

A quality by design HPLC method for cephalosporin analysis in pharmaceuticals and water samples with environmental impact assessment

The present study applied a combined analytical quality-by-design and green analytical chemistry approach to develop an HPLC method for the determination of four cephalosporin pharmaceuticals in both their formulations and water samples. These drugs include ceftriaxone, cefotaxime, ceftazidime and cefoperazone. A Box-Behnken experimental design was employed to optimize three chromatographic parameters: mobile phase composition, flow rate and buffer pH. The predicted optimal conditions involved using a mobile phase of acetonitrile and 0.04 M phosphate buffer at pH 6 in a 7:93 (v/v) ratio, pumped at 1.3 mL/min through a Nucleosil C18 (4.6 × 250 mm, 5 μm) column with UV detection at 240 nm. Under these optimum conditions, the developed HPLC method successfully separated the four drugs with good resolution in less than 6 min. Linearity was established across the concentration ranges of 5-300 µg/mL for ceftriaxone and cefotaxime, 5-400 µg/mL for ceftazidime and 5-100 µg/mL for cefoperazone. Furthermore, full validation of the method in terms of accuracy, precision, specificity and robustness was carried out as per ICH guidelines. The greenness profile of the optimized HPLC method was also evaluated using the Analytical GREEnness (AGREE) tool and found to be environmentally friendly with AGREE score of 0.75, making it a greener alternative for quality control and routine analysis of the investigated cephalosporins in their pharmaceutical formulations and tap water samples. Furthermore, the blueness assessment of the proposed HPLC method using the blue applicability grade index (BAGI) tool yielded a value of 77.5, indicating its high analytical practicality and substantial potential for routine analysis applications.

Contactless Conductivity Detection for Capillary Electrophoresis-Developments From 2020 to 2024

The review covering the development of capillary electrophoresis with capacitively coupled contactless conductivity detection from 2020 to 2024 is the latest in a series going back to 2004. The article considers applications employing conventional capillaries and planar lab-on-chip devices as well as fundamental and technical developments of the detector and complete electrophoresis instrumentation.

Artificial Intelligence to Close the Gap between Pharmacokinetic/Pharmacodynamic Targets and Clinical Outcomes in Critically Ill Patients: A Narrative Review on Beta Lactams

Antimicrobial dosing can be a complex challenge. Although a solid rationale exists for a link between antibiotic exposure and outcome, conflicting data suggest a poor correlation between pharmacokinetic/pharmacodynamic targets and infection control. Different reasons may lead to this discrepancy: poor tissue penetration by β-lactams due to inflammation and inadequate tissue perfusion; different bacterial response to antibiotics and biofilms; heterogeneity of the host's immune response and drug metabolism; bacterial tolerance and acquisition of resistance during therapy. Consequently, either a fixed dose of antibiotics or a fixed target concentration may be doomed to fail. The role of biomarkers in understanding and monitoring host response to infection is also incompletely defined. Nowadays, with the ever-growing stream of data collected in hospitals, utilizing the most efficient analytical tools may lead to better personalization of therapy. The rise of artificial intelligence and machine learning has allowed large amounts of data to be rapidly accessed and analyzed. These unsupervised learning models can apprehend the data structure and identify homogeneous subgroups, facilitating the individualization of medical interventions. This review aims to discuss the challenges of β-lactam dosing, focusing on its pharmacodynamics and the new challenges and opportunities arising from integrating machine learning algorithms to personalize patient treatment.

Simple, fast, and simultaneous determination of orthophosphate, pyrophosphate, and tripolyphosphate by capillary electrophoresis with capacitively coupled contactless conductivity detection

This work describes a novel analytical method using capillary electrophoresis (CE) with capacitively coupled contactless conductivity detection (C4D) for simultaneous, simple, and rapid determination of three inorganic phosphates (orthophosphate, pyrophosphate, and tripolyphosphate) widely used as food additives and in pharmaceutical formulations. A background electrolyte composed of 0.5 mol L-1 acetic acid provided fast separation (around 3.0 min) and good separation efficiency and peak resolution. Linearity in the concentration range of 10-500 mg L-1 was confirmed by the coefficients of determination (R2) higher than 0.99. The limits of detection varied from 0.41 to 0.58 mg L-1. The accuracy of the proposed method was assessed by recovery tests conducted at three concentration levels in tap water samples, food, and personal hygiene products. Recovery values varying from 81% to 118% were achieved, indicating an acceptable accuracy. The proposed CE-C4D successfully determined the three inorganic phosphates in the analyzed samples.

Highly sensitive and selective detection of amoxicillin using molecularly imprinted ratiometric fluorescent nanosensor based on quantum dots

A dual-emission ratiometric fluorescence sensor (CDs@CdTe@MIP) with a self-calibration function was successfully constructed for AMO detection. In the CDs@CdTe@MIP system, non-imprinted polymer-coated CDs and molecule-imprinted polymer-coated CdTe quantum dots were used as the reference signal and response elements, respectively. The added AMO quenched the fluorescence of the CdTe quantum dots, whereas the fluorescence intensity of the CDs remained almost unchanged. The AMO concentration was monitored using the fluorescence intensity ratio (log(I647/I465)0/(I647/I465)) to reduce interference from the testing environment. The sensor with a low detection limit of 0.15 μg/L enabled detection of the AMO concentration within 6 min. The ratiometric fluorescence sensor was used to detect AMO in spiked pork samples; it exhibited a high recovery efficiency and relative standard deviation (RSD) of 97.94-103.70% and 3.77-4.37%, respectively. The proposed highly sensitive and selective platform opens avenues for sensitive, reliable, and rapid determination of pharmaceuticals in the environment and food safety monitoring using ratiometric sensors.

Does PAD and microcirculation status impact the tissue availability of intravenously administered antibiotics in patients with infected diabetic foot? Results of the DFIATIM substudy

Aims/hypothesis

The aim of this substudy (Eudra CT No:2019-001997-27)was to assess ATB availability in patients with infected diabetic foot ulcers(IDFUs)in the context of microcirculation and macrocirculation status.

Methods

For this substudy, we enrolled 23 patients with IDFU. Patients were treated with boluses of amoxicillin/clavulanic acid(AMC)(12patients) or ceftazidime(CTZ)(11patients). After induction of a steady ATB state, microdialysis was performed near the IDFU. Tissue fluid samples from the foot and blood samples from peripheral blood were taken within 6 hours. ATB potential efficacy was assessed by evaluating the maximum serum and tissue ATB concentrations(Cmax and Cmax-tissue)and the percentage of time the unbound drug tissue concentration exceeds the minimum inhibitory concentration (MIC)(≥100% tissue and ≥50%/60% tissue fT>MIC). Vascular status was assessed by triplex ultrasound, ankle-brachial and toe-brachial index tests, occlusive plethysmography comprising two arterial flow phases, and transcutaneous oxygen pressure(TcPO2).

Results

Following bolus administration, the Cmax of AMC was 91.8 ± 52.5 μgmL-1 and the Cmax-tissue of AMC was 7.25 ± 4.5 μgmL-1(P<0.001). The Cmax for CTZ was 186.8 ± 44.1 μgmL-1 and the Cmax-tissue of CTZ was 18.6 ± 7.4 μgmL-1(P<0.0001). Additionally, 67% of patients treated with AMC and 55% of those treated with CTZ achieved tissue fT>MIC levels exceeding 50% and 60%, respectively. We observed positive correlations between both Cmax-tissue and AUCtissue and arterial flow. Specifically, the correlation coefficient for the first phase was r=0.42; (P=0.045), and for the second phase, it was r=0.55(P=0.01)and r=0.5(P=0.021).

Conclusions

Bactericidal activity proved satisfactory in only half to two-thirds of patients with IDFUs, an outcome that appears to correlate primarily with arterial flow.

Development and Validation of a Capillary Zone Electrophoresis-Tandem Mass Spectrometry Method for Simultaneous Quantification of Eight β-Lactam Antibiotics and Two β-Lactamase Inhibitors in Plasma Samples

Monitoring plasma concentrations of β-lactam antibiotics is crucial, particularly in critically ill patients, where variations in concentrations can lead to treatment failure or adverse events. Standardized antimicrobial regimens may not be effective for all patients, especially in special groups with altered physiological parameters. Pharmacokinetic/pharmacodynamic (PK/PD) studies highlight the time-dependent antibacterial activity of these antibiotics, emphasizing the need for personalized dosing. Therapeutic drug monitoring (TDM) is essential, requiring rapid and accurate analytical methods for precise determination of drugs in biological material (typically plasma or serum). This study presents a novel capillary zone electrophoresis-tandem mass spectrometry (CZE-MS/MS) method designed for the simultaneous quantification of five penicillin antibiotics, two cephalosporins, one carbapenem, and two β-lactamase inhibitors in a single run. The method involves a simple sample pretreatment-precipitation with organic solvent-and has a run time of 20 min. Optimization of CZE separation conditions revealed that 20 mM ammonium hydrogen carbonate (NH4HCO3) serves as the optimal background electrolyte (BGE). Positive electrospray ionization (ESI) mode, with isopropyl alcohol (IP)/10 mM ammonium formate water solution (50/50, v/v) as the sheath liquid, was identified as the optimal condition for MS detection. Method validation according to the Food and Drug Administration (FDA) guideline for development of bioanalytical methods demonstrated satisfactory selectivity, linearity, recovery, robustness, and stability. The method's practicality was evaluated using the Blue Applicability Grade Index (BAGI), yielding a score of 77.5. Moreover, the greenness of the proposed method was evaluated by two commonly used metric tools-Analytical GREEnness (AGREE) and Green Analytical Procedure Index (GAPI). The developed CZE-MS/MS method offers a practical and reliable approach for quantifying a broad spectrum of β-lactam antibiotics in plasma. Its ability to simultaneously quantify multiple analytes in a single run, coupled with a straightforward sample pretreatment, positions it as a valuable and prospective tool for TDM in critically ill patients.

Strategies for capillary electrophoresis: Method development and validation for pharmaceutical and biological applications-Updated and completely revised edition

This review is in support of the development of selective, precise, fast, and validated capillary electrophoresis (CE) methods. It follows up a similar article from 1998, Wätzig H, Degenhardt M, Kunkel A. "Strategies for capillary electrophoresis: method development and validation for pharmaceutical and biological applications," pointing out which fundamentals are still valid and at the same time showing the enormous achievements in the last 25 years. The structures of both reviews are widely similar, in order to facilitate their simultaneous use. Focusing on pharmaceutical and biological applications, the successful use of CE is now demonstrated by more than 600 carefully selected references. Many of those are recent reviews; therefore, a significant overview about the field is provided. There are extra sections about sample pretreatment related to CE and microchip CE, and a completely revised section about method development for protein analytes and biomolecules in general. The general strategies for method development are summed up with regard to selectivity, efficiency, precision, analysis time, limit of detection, sample pretreatment requirements, and validation.

Ultrasensitive determination of 10 phenothiazine derivatives and their enantiomers in biological fluids by capillary electrophoresis with contactless conductivity detection

In this study, a simple, rapid, and ultrasensitive technique was developed to identify five pairs of phenothiazine drugs by using ultrasound-enhanced and surfactant-assisted dispersive liquid-liquid microextraction (UESA-DLLME), field-amplified sample injection with capillary electrophoresis (FASI-CE), and capacitively coupled capacitively coupled contactless conductivity detection (C4D). During the CE separation process, UESA-DLLME was used for sample clean-up and offline concentration, and FASI-CE was used for the online concentration of phenothiazine enantiomers. At baseline, the five pairs of phenothiazine enantiomer drugs required 18 min for separation. UESA-DLLME was then used to extract 0.01 mM Tween 80 at pH 10 from a sample solution (extraction solvent, 100 mL of dichloromethane). Subsequently, FASI was used to stack the sample solution (buffer, 30 mM 2-(N-morpholino)ethanesulfonic acid/aspartic acid, additive 4 mM hydroxypropyl-γ-cyclodextrin, pH 2.5), and C4D was used for signal detection (amplitude, 2 Vpp; frequency, 400 kHz). The results indicated that the linear range for quantifying all analyte enantiomers was 1.0-150 nM, with a coefficient of determination exceeding 0.99. In addition, the relative standard deviations in the migration time and peak areas for the 10 analytes were less than 3.2% and 7.2%, respectively. The proposed system has a limit of detection (LOD) for the 10 analytes at a signal-to-noise ratio of 3, ranging from 0.24 to 0.28 nM. The sensitivity enhancement, which compares the LOD0 (limit of detection in the normal method) to LOD1 (limit of detection achieved using the proposed UESA-DLLME-FASI-CE-C4D method), varies between approximately 1200 and 2000 for the 10 analytes. Analysis of the 10 separated analytes spiked in urine and serum samples revealed recovery rates of 88%-106% and 89%-105%, respectively. Therefore, this highly sensitive advanced technique was successfully used to analyze phenothiazine enantiomers in urine and serum samples.

On-line preconcentration and determination of sulfadiazine in food samples using surface molecularly imprinted polymer coating by capillary electrophoresis

In this study, on-line preconcentration and selective determination of the trace sulfadiazine (SDZ) existing in milk and hen egg white samples were realized by the capillary electrophoresis using molecularly imprinted polymer (MIP) coated capillary. The capillary coated with MIP was firstly prepared through the surface imprinted techniques, using SDZ as template molecule and dopamine as function monomer and crosslinker, and then amine-terminated poly(2-methyl-2-oxazoline) (PMOXA-NH₂) was introduced onto polydopamine layer to reduce the non-specific adsorption. Successful preparation of SDZ-MIP-PMOXA coating was verified by zeta potential, as well as water contact angle. The SDZ-MIP-PMOXA coated capillary performed well on-line preconcentration of SDZ and the obtained peak area of SDZ was 46 times higher than that one obtained in bare capillary using the same procedure. Then the proposed on-line preconcentration method was fully validated and displayed good linear behavior in the concentration from 5.0 to 100.0 ng/mL, with the limit of detection was low to 1.5 ng/mL; and this method presented excellent accuracy and robustness. The prepared SDZ-MIP-PMOXA coated capillary also showed high selectivity with the imprinting factor of 5.85 and good repeatability during five consecutive runs with the relative standard deviation value of peak area was 1.6%. At last, the application of the prepared SDZ-MIP-PMOXA coated capillary in the detection of SDZ in spiked food samples was investigated, and good recoveries of 98.7-109.3% were obtained.

Microdialysis as a tool for antibiotic assessment in patients with diabetic foot: a review

Diabetic foot is a serious late complication frequently caused by infection and ischaemia. Both require prompt and aggressive treatment to avoid lower limb amputation. The effectiveness of peripheral arterial disease therapy can be easily verified using triplex ultrasound, ankle-brachial/toe-brachial index examination, or transcutaneous oxygen pressure. However, the success of infection treatment is difficult to establish in patients with diabetic foot. Intravenous systemic antibiotics are recommended for the treatment of infectious complications in patients with moderate or serious stages of infection. Antibiotic therapy should be initiated promptly and aggressively to achieve sufficient serum and peripheral antibiotic concentrations. Antibiotic serum levels are easily evaluated by pharmacokinetic assessment. However, antibiotic concentrations in peripheral tissues, especially in diabetic foot, are not routinely detectable. This review describes microdialysis techniques that have shown promise in determining antibiotic levels in the surroundings of diabetic foot lesions.