Validation of an HPLC Method for Determination of Cefepime (a Fourth-Generation Cephalosporin). Determination in Human Serum, Cerebrospinal Fluid, and Urine. Pharmacokinetic Profiles

Review on Characterization, Properties, and Analytical Methods of Cefepime

Infection is one of the most important reasons for the increase in the number of deaths worldwide; it can be a bacterial or viral infection. As a result, there are many effective drugs against this infection, especially bacterial ones. Cefepime (CP) is one of the fourth generations of cephalosporins and is distinguished from others in that it can kill both positive and negative bacteria. Therefore, this study focused on the chemical properties of the drug, its uses, and its stability against bacteria. All analysis methods for this drug in pharmaceutical preparations, blood, or plasma were also presented. One of the important problems in these methods is using toxic solvents, which poses a danger to society and the environment. The presentation of these solvents will allow companies to manufacture and use more effective and less toxic solvents.

Monitoring of cefepime in urine by micellar electrokinetic capillary chromatography with ultraviolet detection and liquid chromatography coupled to mass spectrometry

Cefepime monitoring in urine by micellar electrokinetic capillary chromatography with UV detection and liquid chromatography coupled to mass spectrometry via electrospray ionization is described. For micellar electrokinetic capillary chromatography, sample preparation comprised urine dilution and dodecyl-sulfate protein precipitation at pH 4.5, whereas diluted urines were analyzed in the other assay. Both approaches provided suitable conditions for cefepime analysis in urines of healthy volunteers that were spiked with cefepime. Cefepime monitoring by micellar electrokinetic capillary chromatography in samples from patients taking multiple drugs were prone to interferences, whereas liquid chromatography coupled to mass spectrometry provided clean chromatograms and thus selective detection of cefepime in all samples. The latter assay was used to measure urinary cefepime in a prospective pilot study and to assess cefepime stability in urines at 25, 4, -20 and -70°C. The data suggest that urinary cefepime is stable for at least 72 h at all tested temperatures.

Simultaneous determination of zidebactam and cefepime in dog plasma by LC-MS/MS and its application to pre-clinical pharmacokinetic study

A precise and accurate liquid chromatography-tandem mass spectrometric (LC-MS/MS) bioanalytical method has been developed and validated for the simultaneous quantification of zidebactam (ZID) and cefepime (FEP) in dog plasma. Ceftazidime was used as an internal standard. Protein precipitation method was used as sample preparation approach. The calibration curve obtained was linear (r ≥ 0.99) over the concentration range 0.156-80 μg/mL for ZID and 0.312-160 μg/mL for FEP. The method was validated as per US Food and Drug Administration guidelines and the results met the acceptance criteria. A run time of 3.5 min for each sample made it possible to analyze the maximum number of samples per day. The proposed method was successfully applied for pharmacokinetic study in beagle dogs.

Assays for therapeutic drug monitoring of β-lactam antibiotics: A structured review

In some patient groups, including critically ill patients, the pharmacokinetics of β-lactam antibiotics may be profoundly disturbed due to pathophysiological changes in distribution and elimination. Therapeutic drug monitoring (TDM) is a strategy that may help to optimise dosing. The aim of this review was to identify and analyse the published literature on the methods used for β-lactam quantification in TDM programmes. Sixteen reports described methods for the simultaneous determination of three or more β-lactam antibiotics in plasma/serum. Measurement of these antibiotics, due to low frequency of usage relative to some other tests, is generally limited to in-house chromatographic methods coupled to ultraviolet or mass spectrometric detection. Although many published methods state they are fit for TDM, they are inconvenient because of intensive sample preparation and/or long run times. Ideally, methods used for routine TDM should have a short turnaround time (fast run-time and fast sample preparation), a low limit of quantification and a sufficiently high upper limit of quantification. The published assays included a median of 6 analytes [interquartile range (IQR) 4-10], with meropenem and piperacillin being the most frequently measured β-lactam antibiotics. The median run time was 8 min (IQR 5.9-21.3 min). There is also a growing number of methods measuring free concentrations. An assay that measures antibiotics without any sample preparation would be the next step towards real-time monitoring; no such method is currently available.

Application of Savitzky-Golay differentiation filters and Fourier functions to simultaneous determination of cefepime and the co-administered drug, levofloxacin, in spiked human plasma

The present work is concerned with simultaneous determination of cefepime (CEF) and the co-administered drug, levofloxacin (LEV), in spiked human plasma by applying a new approach, Savitzky-Golay differentiation filters, and combined trigonometric Fourier functions to their ratio spectra. The different parameters associated with the calculation of Savitzky-Golay and Fourier coefficients were optimized. The proposed methods were validated and applied for determination of the two drugs in laboratory prepared mixtures and spiked human plasma. The results were statistically compared with reported HPLC methods and were found accurate and precise.

Quantification and stress degradation studies of cefepime/tazobactam in dry injection form by an RP-HPLC method

A simple, specific, precise, accurate, linear, rapid, economic and validated stability indicating an RP-HPLC method for the simultaneous quantification of cefepime and tazobactam in a dry injection dosage form has been developed. Separation was performed on a 5 µm ACE C18column with phosphate buffer, pH adjusted to 4.5 with phosphoric acid: methanol (70:30) at a flow rate of 1 mL/min and at a temperature of 25 °C. Regression analysis showed linearity at a detector wavelength of 290 nm in the range of 200-600 μg/mL for cefepime and 25-75 μg/mL for tazobactam. All of the analytes were adequately resolved with acceptable tailing. The percentage content found for cefepime was 99.98% and of tazobactam was 99.49% in the parenteral formulation. The method was validated in terms of linearity, precision, accuracy, specificity, robustness and system suitability according to ICH guidelines. Stress degradation studies were performed on the placebo and drug products, drugs of interest were well resolved from the degradation products. The developed method was effectively applied for the simultaneous quantification of cefepime and tazobactam in a dry injection formulation.

Clinical pharmacokinetics of antibacterials in cerebrospinal fluid

In the past 20 years, an increased discrepancy between new available antibacterials and the emergence of multidrug-resistant strains has been observed. This condition concerns physicians involved in the treatment of central nervous system (CNS) infections, for which clinical and microbiological success depends on the rapid achievement of bactericidal concentrations. In order to accomplish this aim, the choice of drugs is based on their disposition toward the cerebrospinal fluid (CSF), which is influenced by the physicochemical characteristics of antibacterials. A reduced distribution into CSF has been documented for beta-lactams, especially cephalosporins and carbapenems, on the basis of their hydrophilic nature. However, they represent a cornerstone of the majority of combined therapeutic schemes for their ability to achieve bactericidal concentrations, especially in the presence of inflamed meninges. The good tolerability of beta-lactams makes possible high daily dose intensities, which may be associated with increased probability of cure. Furthermore, the adoption of continuous infusion seems to be a fruitful option. Fluoroquinolones, namely moxifloxacin, and antituberculosis drugs, together with the agents such as linezolid, reach the highest CSF/plasma concentration ratio, which is greater than 0.8, and for most of these drugs it is near 1. For all drugs that are currently used for the treatment of CNS infections, the evaluation of pharmacokinetic/pharmacodynamic parameters, on the basis of dosing regimens and their time-dependent or concentration-dependent pattern of bacterial killing, remains an important aspect of clinical investigation and medical practice.

On-line coupling of solid-phase extraction and capillary electrophoresis for the determination of cefoperazone and ceftiofur in plasma

We present a method for determining two cephalosporins (cefoperazone and ceftiofur) in plasma by on-line solid-phase extraction (SPE)-capillary zone electrophoresis (CZE) with a T-split interface. Using this interface, a part of the SPE elution plug containing the cephalosporins is injected while the rest of the sample is flushed to waste. SPE was carried out using a C(18) micro-precolumn and the cephalosporins presented good retention properties with breakthrough volumes above 1 ml. Using a desorption volume of 426 nl of acetonitrile, recoveries were 75 and 90%, for cefoperazone and ceftiofur, respectively. The resulting elution volume was about 1.8 microl. A deproteinization step was included prior to SPE for the analysis of plasma samples with recoveries of 90 and 57% for cefoperazone and ceftiofur, respectively. With UV detection at 254 nm, linear relationships between the injected concentration and peak area was measured between 10 and 500 ng ml(-1) for standards, and 200 and 1500 ng ml(-1) for plasma samples. Intra-day (n=5) and inter-day (n=5) peak area repeatability were lower than 12% RSD. The detection limits obtained for spiked plasma (100 ng ml(-1) cefoperazone and ceftiofur) are sufficient for applying the method to pharmacokinetic studies.