A green approach to the analysis of co-administered ampicillin/sulbactam and paracetamol in human urine.

The novelty of this work is the simultaneous analysis of sulbactam (SUL), ampicillin (AMP), and paracetamol (PARA) in human urine samples, using the environmentally benign RP-HPLC method. A C18 column was used in chromatographic separation using potassium dihydrogen phosphate (10 mmol L-1, pH 5)/ethanol (90 %, V/V) as the mobile phase; flow rate was 1.00 mL min-1. UV detection at 220 nm was used for quantification. The proposed method showed good linearity in the concentration ranges of 2.20-250.00 µg mL-1 for SUL, 2.50-250.00 µg mL-1 for PARA, and 14.50-250.00 µg mL-1 for AMP. Direct injection of urine samples with no prior extraction was performed. This method was found successful in moving towards greener studies of drugs' urinary excretion, by decreasing hazardous solvent consumption and waste. Moreover, the method was applied to investigate the urinary excretion of the drugs and possible interaction between ampicillin and paracetamol.

Determination of sulbactam in raw bovine milk by isotope dilution-ultra-high-performance liquid chromatography-tandem mass spectrometry.

We developed a sensitive and selective isotope dilution ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for the determination of sulbactam residue in raw bovine milk. Sulbactam and internal standard, sulbactam-d5, were extracted from raw bovine milk via liquid-liquid extraction and enriched with strong anion exchange solid-phase extraction cartridges and finally analyzed by using UPLC-MS/MS with multiple reaction monitoring mode. The method was validated according to European regulations. The calibration curve showed good linearity, with a correlation coefficient of 0.9998. Decision limit and detection capability of sulbactam were determined by matrix calibration curve and were 0.0445 and 0.0517 µg/L, respectively. The recoveries of sulbactam in fortified raw bovine milk ranged from 72.1 to 91.5%, with the intra- and interday relative standard deviations ranging from 3.0 to 18.9%. Furthermore, the developed method was applied to analyzing real raw bovine milk samples collected from dairy farms in Beijing, China. Sulbactam was not determined in all samples. The proposed method could ultimately serve as a methodological foundation for the determination of sulbactam in different types of raw milk and dairy products.

Dual-channel Microchip Electrophoresis with Amperometric Detection System for Rapid Analysis of Cefoperazone and Sulbactam.

A dual-channel microchip electrophoresis (ME) with in-channel amperometric detection was developed for cefoperazone and sulbactam determination simultaneously. In this study, a microelectrode detector was made of gold nanoparticles (GNPs) modified indium tin oxide (ITO)-coated poly-ethylene terephthalate (PET) film. The parameters including detection potential applied on working electrode, buffer concentration and pH value were optimized to improve the detection sensitivity and separation efficiency of cefoperazone and sulbactam. Under the optimal conditions, sensitive detection of cefoperazone and sulbactam was obtained with limits of detection (LODs) (S/N = 3) of 0.52 and 0.75 µg/mL, respectively. The plasma sample, which was from a patient with a brain injury taking Sulperazone, was successfully detected with a simple sample pretreatment process by dual-channel ME amperometric detection. This rapid and sensitive method possesses practical potential in clinical applications, and could provide a guidance for clinical rational drug use.

Ultraviolet spectrophotometry (dual wavelength and chemometric) and high performance liquid chromatography for simultaneous estimation of meropenem and sulbactam sodium in pharmaceutical dosage form.

UV spectrophotometric and high performance liquid chromatography (HPLC) methods were developed for simultaneous determination of meropenem (MERM) and sulbactam sodium (SB) in injection. UV spectrophotometric methods were developed using 0.1N sodium hydroxide as solvent. The Beer's plot for dual wavelength method was linear in the range of 4-24 µg mL(-1) and 2-12 µg mL(-1) for MERM and SB, respectively. The percent recoveries were found to be 98.52±1.23% for MERM and 101.45±1.1% for SB. Chemometrics assisted UV spectrophotometry was performed using Partial Least Square (PLS) analysis model and Principal Component Regression (PCR) analysis model. The % recoveries of the MERM were found to be 100.61±0.06% and 101.31±0.12% using PLS and PCR, respectively. The % recoveries of the SB were found to be 98.29±0.09% and 97.61±0.13% using PLS and PCR, respectively. Chromatography was performed on Hypersil BDS C18 column using methanol:acetonitrile:water (10:20:70 v/v/v) as mobile phase. The retention times of MERM and SB were found to be 2.9 min and 2.25 min, respectively. Developed HPLC method was found to be linear in the range of 50-250 µg mL(-1) and 25-125 µg mL(-1) for MERM and SB, respectively. The % recoveries were found to be 98.85±0.25% and 98.63±0.34% for MERM and SB, respectively. The developed analytical methods did not show any interference of the excipients when applied to pharmaceutical dosage form.

Preparation of ZnS:Ni/ZnS quantum dots with core/shell structure and application for detecting cefoperazone-sulbactam.

ZnS:Ni quantum dots (QDs) have been synthesized via a water-soluble route, which were coated by ZnS shell through surface modification to give ZnS:Ni/ZnS QDs. The QDs were characterized by atomic force microscope, X-ray diffraction, infrared spectrometry and fluorescent spectrometry. Then, a novel method for the determination of cefoperazone-sulbactam (CPZ-SBT) in aqueous solutions has been developed based on the enhancement of fluorescence of ZnS:Ni/ZnS QDs in the presence of CPZ-SBT. Under the optimal conditions, the enhanced fluorescence intensity (ΔF) was proportional to CPZ-SBT concentration in the range of 8.0×10(-6)-1.0×10(-4) g/L with a detection limit of 1.0×10(-7) g/L. The method was employed for the determination of CPZ-SBT in sample to give satisfactory result. Compared with others, this method was more sensitive, fast and simple with low limit detection.

[Experimental study on concentrations and pharmacokinetics of antibiotics in bile and evaluation of their microbicidal potential].

OBJECTIVE: To study the concentrations and pharmacokinetics of 6 different kinds of antibiotics in rabbit bile, and evaluate their microbicidal potential. METHODS: Thirty-six health rabbits were randomly divided into 6 groups, and each group was 6 rabbits. After anaesthesia, the common bile duct of rabbit was isolated and cumulated with a silicone tube. The rabbits were administered intravenously with the equal-effect dose of antibiotics. Bile (1.5 ml) was collected at different time points after administration, and the concentration of antibiotics of bile was assayed by high performance liquid chromatography. The bile drug concentration-time data were processed by software to figure out the pharmacokinetic parameters such as maximum concentration (C(max)), peak time (T(max)), half-life time (T(1/2)), clearance (CL) and apparent volume of distribution (VD). The bile antibiotics concentration contrasted to the minimum inhibitory concentration (MIC), and attained the bactericidal index (C(max)/MIC) and the time when the drug concentration exceeded the MIC (T(>MIC)). RESULTS: The C(max) and T1/2 of each antibiotic were as the followings: piperacillin (7 950 ± 3 023) mg/L and (1.97 ± 1.23) h, ceftriaxone (1 104 ± 248) mg/L and (3.14 ± 0.57) h, cefoperazone (5 215 ± 2 225) mg/L and (0.89 ± 0.13) h, meropenem (31.97 ± 12.44) mg/L and (0.36 ± 0.11) h, levofloxacin (66.3 ± 36.9) mg/L and (3.32 ± 2.57) h, metronidazole (28.2 ± 10.2) mg/L and (0.81 ± 0.33) h, respectively. Piperacillin/tazobactam and cefoperazone/sulbactam had the largest bactericidal index and the longest T(>MIC), and their bactericidal indexes were (62.1 ± 23.6) - (993.8 ± 377.9) and (164.8 ± 69.0) - (659.3 ± 275.9), their T(>MIC) were (6.00 ± 2.53) - (8.00 ± 0.00) h and (6.33 ± 1.97) - (8.00 ± 0.00) h. The bactericidal index and T(>MIC) of levofloxacin were the smallest, which were (2.1 ± 1.2) - (8.3 ± 4.6) and (0.54 ± 0.25) - (2.67 ± 1.03) h . Ceftriaxone and meropenem were as the medium, and their bactericidal indexes and T(>MIC) were (4.3 ± 1.0) - (69.2 ± 15.5) , (1.42 ± 0.65) - (8.00 ± 0.00) h and (2.0 ± 0.8) - (1 031.3 ± 401.4) , (0.29 ± 0.10) - (1.83 ± 0.26) h. The bactericidal index of metronidazole to anaerobic ranged from 7.4 to 294.9, and the T(>MIC) ranged from 1.88 to 5.00 h. CONCLUSIONS: The bile concentrations of six antibiotics all exceed their effective bactericidal concentrations. The concentration-time curves of piperacillin, cefoperazone, meropenem and metronidazole conformed to one-compartment model, and ceftriaxone and levofloxacin are conformed to two-compartment model. Piperacillin/tazobactam and cefoperazone/sulbactam have the largest bactericidal index and the longest T(>MIC), so they can be chosen as the first choice for the therapy of hepatobiliary infection.For the anaerobic, the microbicidal potential of metronidazole is high.

UV spectrophotometric simultaneous determination of cefoperazone and sulbactam in pharmaceutical formulations by derivative, Fourier and wavelet transforms.

Signal processing methods based on the use of derivative, Fourier and wavelet transforms were proposed for the spectrophotometric simultaneous determination of cefoperazone and sulbactam in powders for injection. These transforms were successfully applied to UV spectra and ratio spectra to find suitable working wavelengths. Wavelet signal processing was proved to have distinct advantages (i.e. higher peak intensity obtained, additional smooth function and scaling factor process eliminated) over derivative and Fourier transforms. Especially, a better resolution of spectral overlapping bands was obtained by the use of double signal transform in the sequences such as (i) spectra pre-processed by Fractional Wavelet Transform and subsequently subjected to Continuous Wavelet Transform or Discrete Wavelet Transform, and (ii) derivative - wavelet transforms combined. Calibration graphs for cefoperazone and sulbactam were recorded for the range 10-35 mg/L. Good accuracy and precision were reported for all proposed methods by analyzing synthetic mixtures of cefoperazone and sulbactam. Furthermore, these methods were statistically comparable to RP-HPLC.

Development and validation of a reversed-phase column liquid chromatographic method for the determination of five cephalosporins in pharmaceutical preparations.

A new, simple, rapid, and precise RP-HPLC method has been developed and validated for the determination of five cephalosporins, namely, cefalexin, cefoperazone, ceftriaxone, ceftazidime, and cefepime. The method has been applied successfully for simultaneous determination of cefalexin in a binary mixture with sodium benzoate in a suspension, and cefoperazone in a binary mixture with sulbactam in vials. Chromatographic separation was achieved on a Waters microBondapak C18 column (250 x 4.6 mm id, 10 pm particle size) using the mobile phase monobasic potassium phosphate (50 mM, pH 4.6)-acetonitrile (80 + 20, v/v) with UV detection. A flow rate of 1 mL/min was applied. Linearity, accuracy, and precision were found to be acceptable over the concentration range of 30-300, 3-30, and 15-120 microg/mL for the studied cephalosporins, sodium benzoate, and sulbactam, respectively. The optimized method proved to be specific, robust, and accurate for QC of the cited drugs in their pharmaceutical preparations.

Identification, isolation and characterization of a new degradation product in sultamicillin drug substance.

A new degradant of sultamicillin drug substance was found during the gradient reverse phase HPLC analysis of stability storage samples. The level of this degradant impurity was observed up to 1.0%. The impurity (formaldehyde adduct with 5-oxo-4-phenylimidazolidin-1-yl moiety) was identified by LC/MS and was characterized by ((1)H NMR, (13)C NMR, 2D-NMR ((1)H-(1)H COSY, NOESY, HSQC and HMBC), LC/MS/MS, MS/TOF, elemental analysis and IR. This impurity was prepared by isolation and co-injected into HPLC system to confirm the retention time.

Simultaneous determination of ampicillin, cefoperazone, and sulbactam in pharmaceutical formulations by HPLC with beta-cyclodextrin stationary phase.

An accurate and reproducible method for the simultaneous determination of ampicillin (AMP), sulbactam (SUL), and cefoperazone (CFP) in pharmaceutical formulations by using HPLC with beta-CD stationary phase was developed. It involved the use of the added tetraethylammonium acetate (TEAA) reagent, pH, and methanol as the significant parameters to find the optimum separation condition. A high resolution and selectivity of analytes was obtained by running the mobile phase in methanol-5 mM TEAA buffer = 35:65 (v/v, pH 4.5) at 280 nm. The mean recoveries ranged from 96.6 to 103.3% for AMP in the synthetic mixture, 97.6 to 103.0% for SUL, and 97.0 to 104.0% for CFP. The low LOD (<1.8 microg/mL) and low CV (<0.9%) assured that this method was sensitive and reproducible. The assay of analytes in commercial products exhibited that it was convenient and reproducible for routine analyses of these components in sterilized H(2)O, saline, or 5% dextrose injection solutions.

A new fractional wavelet approach for the simultaneous determination of ampicillin sodium and sulbactam sodium in a binary mixture.

A new application of the fractional wavelet transform (FWT) was proposed for the simultaneous determination of ampicillin (AP) and sulbactam (SB) in a pharmaceutical combination for injection. FWT approach is a new powerful tool for removing noise and irrelevant information from the absorption spectra. Cardinal information having higher peak amplitude, eliminated noise, sharp peaks with shrinking width of spectral range was obtained by the application of FWT procedure to the original absorption spectra. In this paper, FWT approach was subjected to the data vector of the UV-signals obtained from AP and SB in the wavelength range of 211.5-313.8 nm. Derivative transform was applied to the original absorption signal together with its FWT generalization. The calibration graphs for AP and SB were obtained by measuring the FWT and usual derivative amplitudes at zero-crossing points. The method validation was carried out by using the synthetic mixture analysis. Our proposed FWT approach was compared with the usual derivative spectrophotometry and chemometric methods (CLS, PCR and PLS) and a good agreement was reported.

Application of 2-acetylbutyrolactone to spectrofluorimetry: fluorescence properties of Schiff bases derived from 2-acetylbutyrolactone and spectrofluorimetric determination of primary amine-containing compounds.

2-Acetylbutyrolactone (ABL) has been characterized for use as a fluorogenic reagent for the spectrofluorimetric determination of primary amines. The reagent forms strongly fluorescent Schiff bases upon the reaction with primary amines in acid-catalized aqueous solutions or in dimethylformamide (DMF). Sulfamethoxazole (SMX) and ampicillin sodium (AMP Na) were used as model amines of type ArNH(2) and RNH(2), respectively. The reaction conditions, fluorescence spectral properties and the stability of the derivatives have been investigated. The chemistry and the pathway of the reaction have been discussed. Calibration data, accuracy, precision, limits of detection, limits of quantification and other aspects of analytical merit were presented in the text. The utility of ABL for the analysis of the model drugs in pharmaceutical preparations was demonstrated. The results indicated that the proposed methods are equally accurate and precise as the official or other reported methods.

A liquid chromatographic method for simultaneous determination of amoxicillin sodium and sulbactam sodium in a combination formulation.

An isocratic liquid chromatographic method with UV detection at 210nm is described for simultaneous determination of amoxicillin sodium and sulbactam sodium in a new combination formulation. Chromatographic separation of the two drugs was achieved on a Hypersil C(18) column using a mobile phase consisting of a binary mixture of methanol and 0.01mol/l sodium acetate (5:95, v/v). The commonly used paired-ion aqueous mobile phase for the determination of penicillins was avoided in this study. The developed LC method offers symmetric peak shape, good resolution and reasonable retention time for both drugs. Linearity, accuracy and precision were found to be acceptable over the concentration ranges of 155.3-1553.0microg/ml for amoxicillin sodium and 45.0-450.0microg/ml for sulbactam sodium. The proposed LC method can be used for the quality control of formulated products containing these two drugs.

HPLC for in-process control in the production of sultamicillin.

A high-performance liquid chromatographic assay coupled with UV detection (215 nm) was developed for the determination of sultamicillin and its synthesis precursors. The separation of the analytes was performed on a Kromasil C(18) column (15 cm x 4.6 mm i.d., 5 microm) at 20 degrees C. The mobile phase (25 mM phosphate buffer, pH 7.0 and acetonitrile 48%) was pumped at a flow rate of 1.0 ml min(-1). This method is sensitive (limits of detection ranged between 0.4 and 1.2 mg l(-1)) and selective for the determination of sultamicillin and could be used for monitoring different synthetic routes.

Application of micellar electrokinetic chromatography to the determination of sultamicillin in oral pharmaceutical preparations.

A micellar electrokinetic capillary electrophoretic method for determination of sultamicillin in Unasyn oral preparations--tablets and suspension--was evaluated. Phosphate-borate buffer at pH 7.0 containing 1.0% sodium dodecylsulfate was used as a mobile phase. The elaborated method ensures separation of sultamicillin from p-toluenesulfonic acid and the impurities, ampicillin, sulbactam and penicillamine. The method was validated for specificity, reproducibility, precision, accuracy and assay linearity (in a concentration range of sultamicillin of 0.05-1.5 mg/ml). Statistical analysis by Student's t-test showed no significant differences between the results obtained by micellar electrokinetic chromatography and HPLC, t(calculated) 0.519 for suspension assays and 0.284 for tablets assays were smaller then t(tabulated).

CE versus LC for simultaneous determination of amoxicillin/clavulanic acid and ampicillin/sulbactam in pharmaceutical formulations for injections.

A rapid, capillary electrophoresis method was evaluated for determination of amoxicillin and clavulanic acid in Augmentin as well as ampicillin and sulbactam in Unasyn preparations for injections. Phosphate-borate buffer at pH 8.66 containing 14.4% sodium dodecyl sulfate was used as a mobile phase. The method was validated. Reproducibility, precision, accuracy and assay linearity in concentration of amoxicillin 0.05-3.03 mg/ml and ampicillin 0.05-3.08 mg/ml, as well as clavulanic acid 0.02-2.02 mg/ml and sulbactam 0.05-2.08 mg/ml were established. This new method is fast, inexpensive and limits consumption of organic solvents when compared with alternative high performance liquid chromatography (HPLC) method, used for drug analysis. Statistical analysis by Student's t-test showed no significant differences between the results obtained by the two methods t(calculated) 0.32 and 1.69 for amoxicillin and clavulanic acid and 0.67 and 1.93 for ampicillin and sulbactam were smaller than t(tabulated).

[Simultaneous determination of sulbactam sodium and cefoperazone sodium in sulperazon by high performance liquid chromatography].

A reversed-phase, isocratic high performance liquid chromatographic method with acid mobile phase can separate sulbactam and cafoperazone within 12 minutes. Column packed with Hypersil ODS2(250 mm x 4.6 mm i.d., 5 microns) was manufactured by Dalian Elite Company. Mobile phase is composed of water (adjusted to pH 4.0 with 1% phosphoric acid) and acetonitrile (80:20, V/V). The detection was performed at 210 nm and the injection volume was 2 microL. Cefoperazone and sulbactam have good linearity in the ranges of 100 mg/L to 800 mg/L and 100 mg/L to 1,000 mg/L with the correlation coefficients of 0.9991 and 0.9997 respectively. This method is easily to be operated and can be applied for manufacturing and medicinal study.

UV-spectrophotometric determination of ampicillin sodium and sulbactam sodium in two-component mixtures.

A simple spectrophotometric method is used for the resolution of the binary mixtures of ampicillin sodium and sulbactam sodium. In aqueous solution, zero-order spectra are subject to interference, so first-derivative spectrophotometry was used to enhance the spectral details allowing the determination of ampicillin sodium from the signal at the zero-crossing point for sulbactam sodium at 268 nm. In 0.1 N sodium hydroxide, sulbactam sodium was determined from the absorbance at 260 nm with negligible contribution from ampicillin sodium. Also, sulbactam sodium was determined without interference using first- and second-derivative spectra in 0.1 N sodium hydroxide at 276 nm (peak-height) and 262-284 nm (peak-to-peak), respectively. The method is rapid, simple, does not require a separation step and allows the determination of each drug without interference from the other. The proposed method has been applied successfully to the assay of these drugs in mixtures and in commercial injections.

Synthesis, analysis and in vitro antibacterial activity of new metal complexes of sulbactam.

Complexes of copper(II), nickel(II) and iron(III) with beta-lactamase inhibitor sulbactam have been synthesized, characterized and identified by elemental analysis, IR and 1H NMR spectroscopy. These complexes have been then tested for their in vitro antibacterial activity in combination with ampicillin against various bacterial species.

[Studies on sultamicillin hydrolysis].

Sultamicillin is an oral mutual pro-drug composed of double esters of formaldehyde hydrate in which one of the hydroxyl groups is esterified with ampicillin and the other with sulbactam. It is hydrolyzed fast in neutral or weakly alkaline condition. When hydrolyzed, it forms ampicillin and hydroxylmethyl sulbactam or sulbactam and hydroxylmethyl ampicillin by different routes. Usually, the former has priority as the two ester bonds have different activities. The ratio of ampicillin to sulbactam in the products is about 3:1. Both the hydroxylmethyl sulbactam and the hydroxylmethyl ampicillin can be further catalyzed by esterase to produce formaldehyde.