Rapid high-performance liquid chromatographic determination of cefepime in human plasma

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.

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.

Compatibility of cefepime and vancomycin during simulated Y-site administration of prolonged infusion

PURPOSE

The physical and chemical compatibility of cefepime and vancomycin at concentrations typically used in prolonged-infusion cefepime infusions was assessed.

METHODS

Samples from a typical Y-site configuration of standard-infusion vancomycin and prolonged-infusion cefepime were collected at various time points during the simulated 4-hour infusion. Samples were analyzed by visual inspection, spectrophotometry, and high-performance liquid chromatography (HPLC). Infusion antibiotics were reconstituted in pairwise combinations of 0.9% sodium chloride injection and 5% dextrose injection to determine the effects of solvent selection on stability. Infusion simulations were performed in triplicate without light protection under fluorescent lighting at room temperature (22.5 °C). Experimental replicates were not run simultaneously but on sequential days due to the considerable time (~12 hours) required to analyze samples obtained from a single infusion simulation and the known time-dependent instability of reconstituted cefepime beyond 24 hours. Physical stability was assessed visually for evidence of particulate formation, haze, precipitation, color change, and gas evolution. Samples were also assessed spectrophotometrically at 600 nm at the time of collection and 24 hours after collection.

RESULTS

Cefepime was compatible with vancomycin at the concentrations tested. The solvent selected (0.9% sodium chloride or 5% dextrose) to reconstitute either antibiotic had no impact on compatibility. Solutions were indistinguishable from positive and negative controls (heat-degraded cefepime and freshly reconstituted cefepime, respectively) at all time points assessed in terms of visual clarity, spectrophotometric absorbance, and HPLC recovery.

CONCLUSION

Cefepime and vancomycin were physically and chemically compatible during simulated Y-site administration of prolonged-infusion cefepime.

A degradation study of cefepime hydrochloride in solutions under various stress conditions by TLC-densitometry

A rapid, accurate and sensitive thin-layer chromatography (TLC) method with densitometric detection has been developed and validated for the determination of cefepime in pharmaceuticals. Chromatographic separation was achieved on a silica gel TLC F254 plates with a mobile phase consisting of ethanol-2-propanol-glacial acetic acid 99.5%-water (4:4:1:3, v/v). Densitometric detection was carried out at wavelength of 266 nm in reflectance/absorbance mode. The validation of the method was found to be satisfactory with high accuracy (from 99.24 to 101.37%) and precision (RSD from 0.06 to 0.36%). Additionally, the stability of cefepime in solution was investigated, including the effect of pH, temperature and incubation time. Favorable retention parameters (Rf , Rs, α) were obtained under the developed conditions, which guaranteed good separation of the studied components. The degradation process of cefepime hydrochloride was described by kinetic and thermodynamic parameters (k, t0.1 , t0.5 and Ea ). Moreover, the chemical properties of degradation products were characterized by the Rf values, absorption spectra, HPLC-MS/MS and TLC-densitometry analysis. As the method could effectively separate the active substance from its main degradation product (1-methylpyrrolidine), it can be employed as a method to indicate the stability of this drug.

Simultaneous determination of cefepime, vancomycin and imipenem in human plasma of burn patients by high-performance liquid chromatography

A liquid chromatographic method with UV detection for simultaneous determination of cefepime, vancomycin and imipenem has been developed. Cefuroxime was used as internal standard. After the clean up of samples by plasma protein precipitation, 5 microl of the extract were injected into the chromatograph and peaks were eluted from the Sulpelcosil LC-18 column using a mobile phase consisting of 0.075 M acetate buffer:acetonitrile (92:8, v/v), pH 5.0 at low rate (0.8 ml/min). The detection wavelength was 230 nm. The limit of detection was 0.4 microg/ml for cefepime and 0.2 microg/ml for vancomycin and imipenem. The method was applied to plasma samples of burn patients, and only small volumes of plasma were required for the simultaneous determination of those antimicrobial agents.

Simultaneous determination of cefepime and vancomycin in plasma and cerebrospinal fluid by MEKC with direct sample injection and application for bacterial meningitis

A simple MEKC with UV detection at 214 nm for simultaneous analysis of cefepime and vancomycin in plasma and in cerebrospinal fluid (CSF) by direct injection without any sample pretreatment is described. The separation of cefepime and vancomycin from biological matrices was performed at 25 degrees C using a BGE consisting of a Tris buffer with SDS and methanol as the electrolyte solution. Under optimal MEKC conditions for biological samples, good separations with high efficiency and short analysis time are achieved. Several parameters affecting the separation of the drugs from biological matrices were studied, including methanol, pH, and concentrations of the Tris buffer and SDS. The linear ranges of the method for the determination of cefepime and vancomycin in plasma and in CSF using imidazole or cefazolin as an internal standard, respectively, were all over the range of 1-30 microg/mL; the detection limits of cefepime and vancomycin in biological matrices (injection 10 kV, 15 s) were 0.3 and 0.5 microg/mL, respectively. The applicability of the proposed method for the determination of cefepime and vancomycin in plasma and CSF collected after intravenous administration of the drugs in patients with meningitis was demonstrated.

Analysis of cephalosporin antibiotics

A comprehensive review with 276 references for the analysis of members of an important class of drugs, cephalosporin antibiotics, is presented. The review covers most of the methods described for the analysis of these drugs in pure forms, in different pharmaceutical dosage forms and in biological fluids.

Simultaneous determination of cefepime and L-arginine by micellar electrokinetic chromato- graphy and applications to commercial injections

A simple micellar electrokinetic chromatography (MEKC) with UV detection is described for simultaneous analysis of cefepime and L-arginine. The determination of cefepime and L-arginine in pharmaceutical preparations was performed at 25degreesC using a background electrolyte consisting of Tris buffer with sodium dodecyl sulfate (SDS) as the electrolyte solution. Several parameters affecting the separation of the drugs were studied, including the pH and concentrations of the Tris buffer and SDS. Under optimal MEKC conditions, good separation with high efficiency and short analysis times is achieved. Using cefazolin as an internal standard, the linear ranges of the method for the determination of cefepime and L-arginine were over 5-100 microg/mL; the detection limits of cefepime (signal to noise ratio = 3; injection 3.45 kPa, 3 s) and L-arginine (signal to noise ratio = 3; injection 3.45 kPa, 3 s) were 2 microg/mL and 4 microg/ mL, respectively. Applicability of the proposed method for the determination of cefepime and L-arginine in commercial injections was demonstrated.

Determination of ceftazidime and cefepime in plasma and dialysate-ultrafiltrate from patients undergoing continuous veno-venous hemodiafiltration by HPLC

We have developed and validated a new, rapid and reproducible HPLC method for the determination of cefepime and ceftazidime in plasma and dialysate-ultrafiltrate samples obtained from intensive care unit (ICU) patients undergoing continuous veno-venous hemodiafiltration (CVVHDF). The method for plasma samples involved protein precipitation with acetonitrile, followed by washing with dichloromethane to remove apolar lipophilic compounds. Dialysate-ultrafiltrate samples did not require any preparation. Separation was performed on a muBondapak C18 (30 cm x 3.9 mm x 10 microm) with UV detection. The mobile phase contained acetate buffer: ACN and was delivered at 2 ml/min. The coefficients of determination of the calibration curves were always > or = 0.998 and R.S.D.% of the response factors <10%. The intra and inter-assay precision and accuracy of the quality controls (QC) and limit of quantification (LOQ) were satisfactory in all cases. Plasma and dialysate-ultrafiltrate samples were stable at -20 and -80 degrees C for 2 months and also after three freeze/thaw cycles. Dialysate-ultrafiltrate samples were stable in the chromatographic rack for 24h at room temperature, but we recommend storing processed plasma samples at 4 degrees C until the analysis. The described method has proved to be useful to give accurate measurements of ceftazidime and cefepime in samples obtained from patients undergoing CVVHDF.

Relationship between pharmacokinetics and pharmacodynamics of beta-lactams and outcome

The in-vitro susceptibility of an organism and the pharmacokinetics of an antimicrobial agent are two basic factors on which the choice of standardised treatment regimens is based. However, the inter-individual variability of these factors, which modifies the exposure of bacteria to an antibiotic in terms of time and quantity, is not usually taken into account. In 87 patients treated with beta-lactams (ceftriaxone, cefepime or piperacillin), the probability of failure was greater when the infectious process was located in tissues with barriers to the distribution of beta-lactams. Mean MICs of piperacillin and cefepime, but not ceftriaxone, were below the breakpoints in cases of both recovery and failure, but organisms isolated from patients with a poor outcome had higher MICs. Therefore, the use of breakpoints to determine the susceptibility of microorganisms was not satisfactory in predicting the outcome for a large number of patients. If MICs are determined and plasma concentrations are monitored, dosages can be adjusted according to these parameters, thereby allowing antibiotic treatment to be individualised.

Voltammetric behavior of cefixime and cefpodoxime proxetil and determination in pharmaceutical formulations and urine

Electrochemical reduction behavior of cephalosporins, Cefixime (CF) and Cefpodoxime Proxetil (CP) have been studied by using different voltammetric techniques in Britton-Robinson buffer system. Two well defined cathodic waves are observed for both the compounds in the entire pH range. Number of electrons transferred in the reduction process was calculated and the reduction mechanism is proposed. The results indicate that the process of both the compounds is irreversible and diffusion-controlled. The peak currents for CF and CP are found to be linear over the range of concentration 6.0 x 10(-8) to 1.2 x 10(-5) mol l(-1) and 8.8 x 10(-8) to 1.1 x 10(-5) mol l(-1), respectively. The lower detection limits are found to be 4.6 x 10(-8) and 8.52 x 10(-8) mol l(-1) for the two compounds. A differential pulse voltammetric method has been developed for the determination of these drugs in pharmaceutical formulations and urine samples.

High-performance liquid chromatographic determination of cefepime in human plasma and in urine and dialysis fluid using a column-switching technique

A high-performance liquid chromatographic method with UV absorbance was developed for the analysis of cefepime in human plasma and urine, and in dialysis fluid. Detection was performed at 280 nm. The assay procedure for cefepime in plasma involves the addition of an internal standard (cefpirome) followed by treatment of the samples with trichloracetic acid, acetonitrile and dichloromethane. To quantify cefepime in diluted urine (1:20) and in the dialysis fluid, samples spiked with the internal standard (cefpirome) were analysed using a column-switching technique. The HPLC column, Nucleosil C18, was equilibrated with an eluent mixture composed of acetonitrile-ammonium acetate (pH 4). Linear detector responses were observed for the calibration curve standards in the range 0.5 to 100 microg/ml, which spans what is currently thought to be the clinically relevant range for cefepime concentrations in body fluids. The limit of quantification was 0.5 microg/ml in the three matrices. Extraction recoveries proved to be more than 84%. Precision, expressed as %RSD, was in the range 1.5 to 9%. Accuracy ranged from 93 to 105%. This method was used to follow the time course of the concentration of cefepime in plasma, urine and dialysate outlet samples after a 10-min infusion period of 2 g of this drug in patients with acute renal failure undergoing hemodiafiltration.