Optimization of HPLC method for determination of cefixime using 2-thiophenecarboxaldehyde as derivatizing reagent: A new approach

Development, validation and greenness assessment of a new electro-driven separation method for simultaneous analysis of cefixime trihydrate and linezolid in their fixed dose combination

The establishment and validation of a straightforward, accurate, and eco-friendly capillary zone electrophoretic-diode array detection (CZE-DAD) procedure has been presented for concurrent measurement of two common antibiotics, namely, linezolid (LIN) and cefixime trihydrate (CEF), in their binary mixture or combined dosage form. The selected fused silica capillary has total and effective lengths equal to 58.5 cm and 50 cm, respectively, with a 50 µm internal diameter. Injections were performed utilizing 100 mM borate buffer at pH 10.2 as the background electrolyte (BGE) with a 15.0 s injection time. The finally utilized voltage was 30 kV. DAD was programmed to measure LIN at 250 nm and CEF at 285 nm. In less than 6 min, the two cited drugs were resolved at 2.51 and 5.47 min for LIN and CEF respectively. The introduced procedure had a linear response in the concentration range of 5-50 μg/mL for both analytes with correlation coefficients > 0.9999. Detection and quantification limits were 1.213 and 4.042 μg/mL, respectively, for LIN and 0.301 and 1.004 μg/mL, respectively, for CEF. Validation was conducted according to the International Council for Harmonization (ICH), concerning linearity, detection and quantitation limits, range, accuracy, precision, selectivity, and robustness. Precision was found acceptable due to the low relative standard deviation (RSD%) values that did not exceed 1.86% either for repeatability or for intermediate precision. Additionally, the adequately recovered concentrations and the low values of percentage relative error (Er%) provide evidence of the accuracy of the proposed method. On the other hand, the robustness of the introduced method was affirmed by the acceptable RSD% values that did not exceed 0.6% after deliberate changes in the following procedure parameters: buffer concentration, buffer pH, and wavelength. Finally, the ability of the presented method to quantify the two tested drugs in laboratory-prepared tablets was confirmed by the adequate recoveries (≥ 99%) utilizing the standard-addition procedure, along with the absence of any significant difference between the proposed method and the reference method as proven by the student's t-test and the variance-ratio F-test values that did not exceed the theoretical ones. The analytical Eco-Scale and the analytical GREEness metric (AGREE) were the tools utilized for greenness assessment. This CZE procedure is the first electro-driven separation method that was utilized for the analysis of both antibiotics in their combined laboratory-prepared tablets with no interference from the co-formulated adjuvants.

A Validated RP-HPLC Method for Simultaneous Determination of Cefixime and Clavulanic Acid Powder in Pediatric Oral Suspension

A new reverse phase high-performance liquid chromatography (RP-HPLC) method was developed and validated for the simultaneous estimation of pediatric oral powder formulation containing cefixime (CFX) and clavulanic acid (CVA). In this research, an analytical C18 (4.6 mm × 25 cm), 5 μm column was used for chromatographic separation with a mixture of methanol and water containing disodium hydrogen phosphate in ratio of 20 : 80 v/v as the mobile phase (pH 5.5 adjusted with orthophosphoric acid) at a flow rate of 1.0 mL/min. The detecting wavelength and run time were 220 nm and 15 min, respectively. Moreover, the column temperature was maintained at 30°C. The analytical method was validated prior to meeting the conditions specified by International Conference on Harmonization (ICH) and the parameters were specificity, linearity, limit of detection (LOD), limit of quantification (LOQ), accuracy, precision, robustness, and solution stability. The calibration curve was found to be linear between the concentration ranges of 0.024–0.036 mg/mL and 0.032–0.048 mg/mL for CFX and CVA, respectively. Furthermore, the LOD and LOQ of CFX were 0.0008 and 0.0025 μg/mL, respectively. Accordingly, LOD and LOQ of CVA were 0.0021 and 0.0065 μg/mL, respectively. The accuracy of the optimized method was examined by recovery studies and the mean recovery was observed to be 98.96% and 99.05% for CFX and CVA, respectively, at 100% spiked level. The repeatability testing for both standard and sample solutions revealed that the method is precise within the acceptable range and the %RSD of the precision was <2%. In addition, the findings of specificity, linearity, accuracy, precision, robustness, LOD, LOQ, and solution stability studies of both CFX and CVA were within the criteria of acceptable limit as well.

A rapid HPLC–DAD method for quantification of amikacin in pharmaceuticals and biological samples using pre-column derivatization with Hantzsch reagent

Amikacin (AMK) is an important member of aminoglycoside class, and its determination has therapeutic importance due to its matchless potency against gram –ve pathogens. Due to narrow therapeutic window, its monitoring in clinical samples is inevitable. Direct determination of AMK using HPLC with UV–visible detection is not possible because of its limited absorbance. Herein, Hantzsch reagent (mixture of acetylacetone, formaldehyde and acetate buffer) was used as pre-column derivatization for AMK. UV–visible detection was performed at 340 nm. Separation and identification of derivatized drug (amikacin) were carried out using C-18 column Kromasil 100 (15 cm × 0.46 mm, 5 μm) with isocratic mobile phase elution of pH 5 (acetate buffer 0.01 M):acetonitrile (30:70 v/v) with flow rate of 1 ml/min. The procedure was able to resolve AMK from endogenous compounds and from cephalosporin drug (most prescribed combination) with run time of 10 min. Under optimized conditions; calibration curve was linear in the range 0.10–25.0 µg/mL with LOD and LOQ values of 0.024 and 0.071 µg/mL. Method was also validated for reproducibility, ruggedness and accuracy. The procedure was found sensitive, robust and precise for the comprehensive analysis (qualitative and quantitative) that was applied for determination of AMK in pharmaceuticals, urine and blood samples.

Determination of cefixime in pure form, in pharmaceutical products and biological samples through fluorescence quenching of eosin Y

A simple, economic and validated spectrofluorimetric method was developed to assay cefixime (CFX). The technique relies on the quenching effect of CFX on the fluorescence intensity of eosin Y in the presence of acetate buffer pH 3.4 to produce an ion-pair complex that is measured at 549 nm using an excitation wavelength of 300 nm. Reaction-influencing factors were carefully investigated and optimized. The fluorescence quenching value was linear to the CFX concentration in the range 0.2-40 μg/ml with a correlation coefficient of 0.992. The calculated limit of detection and limit of quantification were found to be 0.00242 and 0.0080 μg ml^-1 , respectively. The selectivity of the method was confirmed by studying the effects of excipients and no interference was distinguished. The developed method was used to determine CFX in marketable products and in biological samples. To validate the method, directives of the International Conference on Harmonization were applied and per cent recoveries obtained ranged from 95.30 to 102.50% for pharmaceutical products and from 97.00 to 103.00% for biological fluids.

Surface plasmon resonance of gold nanoparticles as a colorimetric sensor for indirect detection of Cefixime

This study reports a colorimetric sensor with excellent sensitivity to detect Cefixime base on gold nanoparticles. Cefixime is an antibiotic which has a wide range of applications in medicine. Cefixime did not change the surface plasmon resonance bond in gold nanoparticles solution; therefore, there was no change in the color solution of gold nanoparticles. The presence of Alizarin Red S in the system was necessary for the degradation of Cefixime, resulting in the aggregation of gold nanoparticles and a color change from red to blue. As a result of aggregation, the localized surface plasmon resonance band of gold nanoparticles decreased to around 525 nm and a new red-shifted band at 640 nm appeared which increases gradually as the function of Cefixime concentration. A unique detection limit (2.5 ng mL^-1) was achieved for Cefixime in comparison with other colorimetric methods. Relative standard deviations (RSD) for 40.0 and 140.0 ng mL^-1 of Cefixime were 2.6 and 1.8% for intra-day respectively. A possible mechanism was discussed for the surface plasmon resonance changes of AuNPs in the presence of Cefixime. The proposed method was applied to detect Cefixime in pharmaceutical samples with satisfactory results. This system is low-cost and is highly sensitive with no need for any preconcentration steps or using any expensive or sophisticated instrumentation.

Determination of cefixime using a novel electrochemical sensor produced with gold nanowires/graphene oxide/electropolymerized molecular imprinted polymer

Quantitative analysis of antibiotics is very important because these drugs are widely used to prevent or treat various diseases. Cefixime (CEF, a semi-synthetic antibiotic and the third generation of cephalosporin) is a bactericidal medicine that prevents formation of cell walls in bacteria as well as their growth and proliferation. It, thus, causes the death of bacteria. Antibiotics such as CEF are generally determined by chromatography and spectroscopy techniques. Electrochemical sensors are one of the fast, convenient and low-cost tools for measuring this type of compounds. In this research, an electrochemical sensor was constructed by modifying a glassy carbon electrode (GCE) with expanded graphene oxide and gold nanowires, and then its surface was electropolymerized with a molecular imprinted polymeric layer of polyaniline. The morphological characterization of the obtained film was carried out by scanning and transmission electron microscopy (SEM and TEM). The proposed sensor was analytically characterized on the purpose of comparing it to other modified GCEs. The sensor could work linearly for the concentration range of 20.0-950.0 nM and with a limit of detection of 7.1 nM. It was successfully applied to determine CEF traces in biological samples (i.e. serum and urine) with excellent recovery percentages.