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1.
A simple, rapid and validated capillary electrophoretic method has been developed for the separation and determination of ofloxacin and ornidazole in pharmaceutical formulations with detection at 230 nm. Optimal conditions for the quantitative separations were investigated. Analysis times shorter than 4 min were obtained using a background electrolyte solution consisting of 25 mmol/L phosphoric acid adjusted with 1 m Tris buffer to pH 8.5, with hydrodynamic injection of 5 s and 20 kV separation voltage. The validation criteria for accuracy, precision, linearity and limits of detection and quantitation were examined and discussed. An excellent linearity was obtained in concentration range 25–250 µg/mL. The detection limits for ofloxacin and ornidazole were 1.03 ± 0.11 and 1.80 ± 0.06 µg/mL, respectively. The proposed method has been applied for the analysis of ofloxacin and ornidazole both individually and in a combined dosage tablet formulation. The proposed validated method showed recoveries between 96.16 and 105.23% of the nominal contents. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

2.
A capillary electrophoretic method coupled to a diode array detector (CE-DAD) was developed and validated for the simultaneous determination of metformin hydrochloride (MET), the dipeptidyl peptidase-4 (DPP-4) inhibitor saxagliptin hydrochloride (SAX), and the sodium glucose co-transporter (SGLT 2) inhibitor dapagliflozin (DAP). The proposed method was used for the determination of these drugs in binary antidiabetic combinations namely, SAX/MET, combination I, DAP/MET, combination II, and SAX/DAP, combination III. CE separation was performed on a fused silica capillary with background electrolyte consisting of 30?mM phosphate buffer (pH 6.0) with a high voltage of 30?kV, a pressure of 20 mbar, and an injection time of 40?s. The compounds were detected at 203?nm for SAX/DAP and 250?nm for MET. The method was linear in the concentration range of 10–200?µ?g/mL (SAX), 1.25–50?µ?g/mL (DAP), and 7.5–1000?µ?g/mL (MET). Full validation of the proposed method was performed as per the ICH guidelines. The obtained errors and deviation values did not exceed 2% assessing good accuracy and precision, respectively. The stability-indicating potential of the proposed method was proved under different stress-degradation conditions. The proposed method was successfully applied to the analysis of the three binary combinations in their tablets.  相似文献   

3.
A green, novel, rapid, accurate and reliable capillary zone electrophoresis method was developed and validated for the simultaneous determination of piperacillin, tazobactam and cefepime in pharmaceutical preparations. Separation was carried out using fused silica capillary (50 µm i.d. × 48.6 cm and 40.2 cm detection length) and applied potential of 20 kV (positive polarity) and a running buffer containing 15 m m sodium borate buffer adjusted to pH 9.3 with UV detection at 215 nm. Amoxicillin was used as an internal standard. The method was suitably validated according to International Conference on Harmonization guidelines. The method showed good linearity in the ranges of 10–100, 20–400 and 10–400 µg/mL with limits of quantitation of 1.87, 3.17 and 6.97 µg/mL and limits of detection of 0.56, 0.95 and 2.09 µg/mL for tazobactam, piperacillin and cefepime, respectively. The proposed method was successfully applied for the analysis of these drugs in their synthetic mixtures and co‐formulated injection vials. The method was extended to the in vitro determination of the two drugs in spiked human plasma. It is considered a ‘green’ method as it consumes no organic solvents. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

4.
A rapid, accurate, precise, and optimized capillary zone electrophoresis assay was established and validated for the simultaneous quantification of metformin and vildagliptin in tablets. The electrophoretic separation was achieved on an untreated bonded silica capillary with a background electrolyte comprising 25 mM of borate buffer at pH 7.5 at 207 nm. The concentration of the buffer and the pH of BGE were optimized using the multivariate optimization method for determining the retention time and peak area. Furthermore, the sample injection time, capillary oven temperature, and applied voltage were optimized. The capillary zone electrophoresis technique was validated for all required parameters as per the International Conference on Harmonization recommendations. The linearity ranged in the concentrations of 5–500 µg/mL and 5–100 µg/mL with the limit of detections of 0.22 µg/mL and 0.40 µg/mL for metformin and vildagliptin, respectively. In addition, the percent relative standard error for repeatability and inter-day precision was within the acceptable range. The mean recoveries determined by the capillary zone electrophoresis method were 99.2% and 100.4% for metformin and vildagliptin, respectively. Finally, the capillary zone electrophoresis process was effectively used for the assays of metformin and vildagliptin in their solid dosage form, and statistical outcomes were in agreement with the outcomes of the previously validated RP-HPLC method.  相似文献   

5.
A capillary zone electrophoresis method was developed for the simultaneous determination of seven phenolic acids, including protocatechuic aldehyde ( 1 ), salvianolic acid C ( 2 ), rosmarinic acid ( 3 ), salvianolic acid A ( 4 ), danshensu ( 5 ), salvianolic acid B ( 6 ), and protocatechuic acid ( 7 ), in Danshen and related medicinal plants. A running buffer composed of 20 mM sodium tetraborate adjusted to pH 9.0, and containing 12 mM β‐cyclodextrin as modifier. Baseline separation was achieved within 17 min running at the voltage of 20 kV, temperature of 25°C and detection wavelength of 280 nm. The relative standard deviations of migration time ranged from 0.2 to 0.7% and the peak area ranged from 1.5 to 3.7% for the seven analytes, indicating the good repeatability of the proposed method. The method was extensively validated by evaluating the linearity (R2 ≥ 0.9992), limits of detection (0.14–0.36 μg/mL), limits of quantification (0.47–1.19 μg/mL), and recovery (96.0–102.6%). Under the optimum conditions, samples of Danshen and related medicinal plants were analyzed using the developed method with high separation efficiency.  相似文献   

6.
The applicability of CZE with mass spectrometric detection for the determination of four chlorine species, namely chloride and three stable chlorine oxyanions, was studied. The main aspects of the proper selection of BGE and sheath liquid for the CE‐MS determinations of anions with high mobility were demonstrated, pointing out the importance of pH and the mobility of the anion in the BGE. The possibility of using uncoated fused silica capillary and common electrolytes for the separation was shown and the advantage of using extra pressure at the inlet capillary end was also presented. The linear range was found to be 1–100 µg/mL for ClO3? and ClO4?, 5–500 µg/mL for ClO2?, and 25–500 µg/mL for Cl?, but the sensitivity can be greatly improved if larger sample volume is injected and electrostacking effect is utilized. The LOD for ClO3? in drinking water was 6 ng/mL, when very large sample volume was injected (10 000 mbar·s was applied).  相似文献   

7.
《Analytical letters》2012,45(3):569-578
Abstract

Applying capillary zone electrophoresis (CZE) to separate the components of Cephradine for Injection: cephradine, and L‐arginine, as well as cephalexin, which is the degradation product of cephradine was studied. The best results were achieved with background electrolyte consisting of 50 mM disodium hydrogen phosphate buffer at pH 6.5 and an applied voltage of 20 kV in a bare fused‐silica capillary. The samples were injected at 50 mbar for 4 s. The capillary temperature was 25°C and the UV detection was performed at a wavelength of 195 nm. Histidine was used as internal standard (IS) to ensure acceptable precision data. The linear ranges of cephradine, L‐arginine, and cephalexin were 93.8–6255.6 µg/mL, 47.9–3195.2 µg/mL, and 6.1–405.4 µg/mL, respectively. Quantitative parameters such as accuracy, precision, limit of detection (LOD), and limit of quantitation(LOQ) were all established in CZE mode.  相似文献   

8.
《Electrophoresis》2018,39(19):2425-2430
Determination of natural preservatives using electrophoretic or chromatographic techniques in fermented milk products is a complex task due to the following reasons: (i) the concentrations of the analytes can be below the detection limits, (ii) complex matrix and comigrating/coeluting compounds in the sample can interfere with the analytes of the interest, (iii) low recovery of the analytes, and (iv) the necessity of complex sample preparation. The aim of this study was to apply capillary zone electrophoresis coupled with contactless conductivity detection for the separation and determination of nisin in fermented milk products. In this work, separation and determination of natural preservative–nisin in fermented milk products is described. Optimized conditions using capillary zone electrophoresis coupled with capacitance‐to‐digital technology based contactless conductivity detector and data conditioning, which filter the noise of the electropherogram adaptively to the peak migration time, allowed precise, accurate, sensitive (limit of quantification: 0.02 μg/mL), and most importantly requiring very minute sample preparation, determination of nisin. Sample preparation includes following steps: (i) extraction/dilution and (ii) centrifugation. This method was applied for the determination of nisin in real samples, i.e. fermented milk products. The values of different nisin forms were ranging from 0.056 ± 0.003 μg/mL to 9.307 ± 0.437 μg/g.  相似文献   

9.
Determination of a widely used antihypertensive combination of atenolol and hydrochlorothiazide was achieved by rapid and eco-friendly high-performance liquid chromatography method combined with fluorescence detection. The response surface methodology is conducive to the complete separation of the two drugs in a shorter analysis time. The separation of the mixture was achieved using an Inertsil C18 analytical column (150 × 4.6 mm, 5 µ). The mobile phase used was ethanol: potassium dihydrogen phosphate at pH 3 (65:35 v/v) and the flow rate was 0.7 mL/min. The fluorescence detector operated at excitation and emission wavelengths of 230 and 310 nm (atenolol) and 270 and 375 nm (hydrochlorothiazide). The linearity of the developed method covered a concentration of atenolol of 0.05–5 µg/mL and a concentration of hydrochlorothiazide of 0.02–1 µg/mL. The greenness of the developed method was evaluated by analytical eco-scale and the recently reported evaluation method, that is, green analytical procedure index, and it was found to be an excellent, sensitive, and green alternative to the reported methods. The developed method was validated according to the ICH guidelines and compared with the reference method. No significant difference was found in terms of accuracy.  相似文献   

10.
A practical chiral CE method, using sulfated‐β‐CD as chiral selector, was developed for the enantioseparation of glycopyrrolate containing two chiral centers. Several parameters affecting the separation were studied, including the nature and concentration of the chiral selectors, BGE pH, buffer type and concentration, separation voltage, and temperature. The separation was carried out in an uncoated fused‐silica capillary of (effective length 40 cm) × 50 μm id with a separation voltage of 20 kV using 30 mM sodium phosphate buffer (pH 7.0, adjusted with 1 M sodium hydroxide) containing 2.0% w/v sulfated‐β‐CD at 25°C. Finally, the method for determining the enantiomeric impurities of RS‐glycopyrrolate was proposed. The method was further validated with respect to its specificity, linearity range, accuracy and precision, LODs, and quantification in the expected range of occurrence for the isomeric impurities (0.1%).  相似文献   

11.
Based on an efficient sample clean‐up and field‐amplified sample injection online preconcentration technique in capillary electrophoresis with contactless conductivity detection, a new analytical method for the sensitive determination of melamine in milk samples was established. In order to remove the complex matrix interference, which resulted in a serious problem during field‐amplified sample injection, liquid–liquid extraction was utilized. As a result, liquid–liquid extraction provides excellent sample clean‐up efficiency when ethyl acetate was used as organic extraction by adjusting the pH of the sample solution to 9.5. Both inorganic salts and biological macromolecules are effectively removed by liquid–liquid extraction. The sample clean‐up procedure, capillary electrophoresis separation parameters and field‐amplified sample injection conditions are discussed in detail. The capillary electrophoresis separation was achieved within 5 min under the following conditions: an uncoated fused‐silica capillary, 12 mM HAc + 10 mM NaAc (pH = 4.6) as running buffer, separation voltage of +13 kV, electrokinetic injection of +12 kV × 10 s. Preliminary validation of the method performance with spiked melamine provided recoveries >90%, with limits of detection and quantification of 0.015 and 0.050 mg/kg, respectively. The relative standard deviations of intra‐ and inter‐day were below 6%. This newly developed method is sensitive and cost effective, therefore, suitable for screening of melamine contamination in milk products.  相似文献   

12.
A micellar electrokinetic chromatography (MEKC) method for the simultaneous determination of the antiviral drugs acyclovir and valacyclovir and their major impurity, guanine, was developed. The influences of several factors (surfactant and buffer concentration, pH, applied voltage, capillary temperature and injection time) were studied. Using tyramine hydrochloride as internal standard, the analytes were all separated in about 4 min. The separation was carried out in reversed polarity mode at 28°C, 25 kV and using hydrodynamic injection (15 s). The separation was effected in a fused‐silica capillary 100 μm × 56 cm and a background electrolyte of 20 mM citric acid–1 M Tris solution (pH 2.75), containing 125 mM sodium dodecyl sulphate and detection at 254 nm. The method was validated with respect to linearity, limit of detection and quantification, accuracy, precision and selectivity. Calibration curves were linear over the range 0.1–1 μg/mL (guanine) and from 0.1 to 120 μg/mL for both valacyclovir and acyclovir. The relative standard deviations of intra‐ and inter‐day migration times and corrected peak areas were less than 5.0%. The proposed method was successfully applied to the determination of the analytes in tablets and creams. From the previous study it is concluded that the stability‐indicating method developed for acyclovir and valacyclovir can be used for analysis of the drug in various stability samples. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

13.
In this study, the capillary electrophoresis-photodiode array detector was employed for the analysis of four iridoid compounds in Gentiana macrophylla Radix (RGM), and the method was optimized based on the concept of analytical quality by design (AQbD). The peak areas relative standard deviation (n = 3) and resolution of the four analytes were selected as critical method attributes. Fractional factorial design test combined with Pareto analysis were employed to screen critical method parameters (buffer concentration, pH, sodium dodecyl sulfate [SDS] micelle concentration, temperature, and voltage). Subsequently, three main factors (buffer concentration, buffer pH, and SDS concentration) were selected by central composite design test for constructing the design space. The optimal separation conditions as follows: capillary column (50.2 cm × 50 µm, detection length 40 cm). Working background electrolyte consisted of 51 mmol/L borax solution (pH = 9.47) and 40 mmol/L SDS. The samples were injected by pressure (5 s at 0.5 psi) and the detection was performed at 254 nm. Applied voltage was 20 kV and column temperature was 23°C. The developed method is rapid and reliable for the quantitative analysis of four iridoid compounds in RGM, providing a reference for the application of AQbD concept in the analysis of natural products.  相似文献   

14.
A simple and rapid method has been developed for the analysis of anthracycline antibiotics doxorubicin (DOX) and daunorubicin (DAU) in human serum using mirochip-based capillary electrophoresis (CE) with laser-induced fluorescence (LIF) detection. In this study, method development included studies of the effect of buffer pH, buffer concentration, organic solvents and separation voltage on sensitivity and separation efficiencies for the CE separation of DOX and DAU. Acetonitrile was found to have significantly improved the sensitivity and separation efficiency. The method was validated with regard to reproducibilities, linearity and limit of detection (LOD). The optimum electrophoretic separation conditions were 10 mM sodium tetraborate buffer at pH 9.5 with 40% acetonitrile (V/V) and a separation voltage of 2.1 kV. DOX and DAU were separated in 60 s under the optimum separation conditions. Linear relationships were obtained between the concentration and peak area (or peak height) in the 1–75 µg mL− 1 range and with the detection limits of 0.3 and 0.2 μg mL− 1 for DOX and DAU, respectively. The stability of both migration time and peak height of the analytes showed relative standard deviations of less than 5% (n = 9). The potential of this method was verified by spiking a human serum sample with the two drugs and analyzing the recovery ratios.  相似文献   

15.
A simple, rapid, capillary zone electrophoresis method was developed and validated for the analysis of two novel aminoalkanol derivatives ( I ) and ( II ) of 1,7‐diethyl‐8,9‐diphenyl‐4‐azatricyclo[5.2.1.02,6]dec‐8‐ene‐3,5,10‐trione, which were found in earlier studies as potential anticancer drugs. Samples were analyzed to demonstrate the specificity and stability indicating ability of the developed method. The samples were extracted using n‐hexane‐ethyl acetate mixture in the ratio of 90:10. Electrophoretic separation was performed on a eCAP fused silica capillary (37 cm length, 50 µm inside diameter) with a 50 mM tetraborate buffer as a background electrolyte adjusted to pH = 2.5. The separation time of ( I ) and ( II ) was achieved within 7 min. In addition, analysis of the two compounds in the serum was conducted. Limits of detection of ( I ) and ( II ) by UV absorbance at 200 nm were achieved in the range of 87.4–92.1 ng/mL. The sufficient recovery was observed in the range of 90.3–99.8%. The quantification limits for the compounds ( I ) and ( II ) were in the range of 279.71–291.03 ng/mL, respectively. The method has been successfully applied to the analysis of compounds ( I ) and ( II ) in serum samples.  相似文献   

16.
As a novel drug delivery system, liposomes were used to improve pharmacokinetics/pharmacodynamics (PK/PD) characters, minimize toxicity, and enhance drug–target selectivity. However, heterogeneity of drug releasing process and liposome itself challenged traditional pharmaceutical analytical techniques, especially in vivo pharmacokinetic studies. In this study, a novel liposomal doxorubicin (L-DOX) pharmacokinetic analysis strategy was developed with capillary electrophoresis coupled with laser-induced fluorescence (CE-LIF) detector. The background electrolyte (BGE) system was composed of borate and sodium dodecyl sulfate (SDS), which was optimized to successfully achieve simultaneous online separation and quantitative analysis of free DOX and liposome-encapsulated DOX. The method was applied to the in vivo pharmacokinetic study of L-DOX in rats. The results showed that the concentration of total DOX (T-DOX) was gradually decreasing, while the concentration of L-DOX was relatively stable, with a concentration of 31.6 ± 4.8 µg/mL within 24 h. It was the first time to achieve liposomal drugs in vivo analysis with CE-LIF. CE-LIF was proved as potential rapidly real-time analytical methods for liposomal drugs in vivo occurrence monitoring.  相似文献   

17.
《Analytical letters》2012,45(4):651-662
A simple, rapid, and sensitive nonaqueous capillary electrophoresis-electrospray ionization-ion trap-mass spectrometry (NACE-ESI-IT-MS) method was developed for determination of matrine and oxymatrine in Sophora Flavescens and medicinal preparations. The conditions for NACE separation and MS detection were systematically optimized. The optimum NACE buffer contained 30 mM ammonium acetate, 1% acetic acid, and 15% acetonitrile in methanol and the applied voltage on separation capillary was set at 25 kV. Berberine was selected as internal standard. In order to generate a stable electrospray, a sheath liquid (isopropanol/H2O, 2/1, v/v) was used, which could also boost the flow through the ESI needle. The matrine and oxymatrine solutions were introduced into MS detection by a syringe pump for collecting the MSn spectra to investigate the main fragment ions and its possible cleavage pathways. Both matrine and oxymatrine showed good linearity in the concentration ranges from 0.5 to 400 µg/mL, with linear correlation coefficient R > 0.99 and the limit of detections were 37.5 ng/mL for matrine and 50.0 ng/mL for oxymatrine, respectively. The recoveries at different content of Sophora Flavescens were 98.3%–102.9% for MT and 95.3%–100.6% for OMT, which indicates the reliability of this method.  相似文献   

18.
A series of 6-(morpholinosulfonyl)quinoxalin-2(1H)-one based hydrazone, hydrazine, and pyrazole moieties were designed, synthesized, and evaluated for their in vitro antimicrobial activity. All the synthesized quinoxaline derivatives were characterized by IR, NMR (1H /13C), and EI MS. The results displayed good to moderate antimicrobial potential against six bacterial, and two fungal standard strains. Among the tested derivatives, six quinoxalin-2(1H)-one derivatives 4a, 7, 8a, 11b, 13, and 16 exhibited a significant antibacterial activity with MIC values (0.97–62.5 µg/mL), and MBC values (1.94–88.8 µg/mL) compared with Tetracycline (MICs = 15.62–62.5 µg/mL, and MBCs = 18.74–93.75 µg/mL), and Amphotericin B (MICs = 12.49–88.8 µg/mL, and MFC = 34.62–65.62 µg/mL). In addition, according to CLSI standards, the most active quinoxalin-2(1H)-one derivatives demonstrated bactericidal and fungicidal behavior. Moreover, the most active quinoxaline derivatives showed a considerable antibacterial activity with bactericidal potential against multi-drug resistance bacteria (MDRB) strains with MIC values ranged between (1.95–15.62 µg/mL), and MBC values (3.31–31.25 µg/mL) near to standard Norfloxacin (MIC = 0.78–3.13 µg/mL, and MBC = 1.4–5.32 µg/mL. Further, in vitro S. aureus DNA gyrase inhibition activity were evaluated for the promising derivatives and displayed potency with IC50 values (10.93 ± 1.81–26.18 ± 1.22 µM) compared with Ciprofloxacin (26.31 ± 1.64 µM). Interestingly, these derivatives revealed as good immunomodulatory agents by a percentage ranging between 82.8 ± 0.37 and 142.4 ± 0.98 %. Finally, some in silico ADME, toxicity prediction, and molecular docking simulation were performed and showed a promising safety profile with good binding mode.  相似文献   

19.
An efficient pressurized capillary electrochromatography (pCEC) method has been successfully developed for the determination of six catechins in tea. The separation was performed on a reversed-phase EP-100-20/45-3-C18 capillary column (total length of 45?cm, effective length of 20?cm, diameter of 100?μm, ODS packing inside for 3?μm). The mobile phase ratio of organic phase, the concentration of phosphate buffer and sodium heptanesulfonate, separation voltage, and other experimental conditions were investigated and optimized. The mobile phase was 15?mM NaH2PO4 and 12?mM sodium heptanesulfonate (pH 3.0)/methanol (64:36) at a flow rate of 0.04?mL/min. Under optimal conditions including applied voltage of ?4?kV and a UV detection wavelength of 230?nm, the six catechins in the tea were well separated. The calibration curves for the analytes had good linearity in the range of 8.02?μg/mL–202.13?μg/mL with a correlation coefficient of 0.9928–0.9997. The limits of detection (LOD) for the six catechins were 4.62?μg/mL–11.63?μg/mL (S/N?=?3). The recoveries of the six catechins were 96.2%–108.4% with a relative standard deviation (RSD) between 0.78% and 4.51%. The method has been used for the determination of six catechins in tea samples with good results.  相似文献   

20.
A systematic Quality by Design approach was employed for developing an isocratic reversed‐phase liquid chromatographic technique for the estimation of ropinirole hydrochloride in bulk drug and pharmaceutical formulations. LiChrospher RP 18‐5 Endcapped column (25 cm × 4.6 mm id) at ambient temperature (25 ± 2°C) was used for the chromatographic separation of the drug. The screening of factors influencing chromatographic separation of the active pharmaceutical ingredient was performed employing fractional factorial design to identify the influential factors. Optimization of the selected factors was carried out using central composite design for selecting the optimum chomatographic conditions. The mobile phase employed was constituted of Solvent A/Solvent B (65:35 v/v) (Solvent A [methanol/0.05 M ammonium acetate buffer, pH 7, 80:20 v/v] and Solvent B [high performance liquid chromatography grade water]) and used at 0.6 mL/min flow rate, while UV detection was performed at 250 nm. Linearity was achieved in the drug concentration range 5–100 µg/mL (R= 0.9998) with limits of detection and quantification of 1.02 and 3.09 µg/mL, respectively. Method validation was performed as per ICH guidelines followed by forced degradation studies, which indicated good specificity of the developed method for detecting ropinirole hydrochloride and its possible degradation products in the bulk drug and pharmaceutical formulations.  相似文献   

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