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A micellar electrokinetic chromatography method for simultaneous assay of ticarcillin and clavulanic acid in Timentin i.v. injection preparation was developed. This method ensures excellent separation of both components of Timentin preparation. The validation of the method was performed, and specificity, reproducibility, precision and accuracy were confirmed. The detection and quantitative limits for Timentin were established in the concentrations 0.04 and 0.08 mg/ml, respectively. The elaborated technique was compared with two methods routinely used-UV and high performance liquid chromatography (HPLC). The obtained results and their statistical analysis proved the same precision of all methods, however, no significant differences were observed between CE and HPLC. [Copyright &y& Elsevier]

Abstract: Ertapenem, a Group 1 carbapenem, is most recently introduced into the market. It is a β-lactam antibiotic that possesses a broad antibacterial spectrum including common community-acquired Gram-positive and Gram-negative aerobic and anaerobic pathogens, but low activity against some nosocomial pathogens such as Pseudomonas aeruginosa, Acinetobacter spp., enterococci and methicillin-resistant staphylococci. The elaborated method of micellar electrokinetic chromatography (MEKC) of ertapenem separation from its impurities was successfully performed using normal stacking mode (NSM) and stacking with reverse migrating micelles (SRMM), followed by UV absorption detection at 214nm. The best results were obtained with 60mM sodium dihydrogen phosphate and 20mM boric acid buffer pH 6.0, as background electrolyte. Uncoated fused-silica capillary and neutral-coated capillary with normal and reverse polarity, and voltage values of +18 and −12kV, respectively, were used throughout the investigation. Sodium dodecyl sulfate was employed as the pseudostationary phase. A comparison of applied techniques, including sensitivity enhancement factors and limits of detection (LOD), is presented. The optimized method was validated in terms of linearity, accuracy and precision. Comparable LOD was obtained using both stacking methods (0.3μg/mL) but better efficiency of ertapenem peak was obtained using NSM. Under the optimum stacking conditions, about 183–4.75-fold and 1289–4.07-fold improvements in peak areas were obtained for NSM and SRMM, respectively, compared to the usual hydrodynamic sample injection (10s). The reproducibility, expressed by relative standard deviations (RSD) of the migration times, for NSM was about 0.96–1.25 and for SRMM was 0.32–0.45. The RSD of corrected peak areas, for NSM was about 1.07–8.14 and for SRMM was 0.74–8.12. The difference in separation time between the two techniques was not obvious. Satisfactory separation was possible after less than 11min of electrophoresis. The evaluated MEKC method was applied in the analysis of medicinal product containing ertapenem: Invanz—ertapenem for injection. [Copyright &y& Elsevier]

Abstract: Linezolid is the first compound of a truly new class of antibiotics—the oxazolidinones. The elaborated method of capillary electrophoresis (CE) of linezolid separation from its achiral impurities was successfully performed using sweeping preconcentration, followed by UV absorption detection at 254nm. The best results were obtained with 125mM Tris buffer, pH 2.0, with addition of 20% (v/v) methanol as background electrolyte. Sodium dodecyl sulfate (150mM) was added to the electrolyte in the inlet vial as the sweeping agent. The separation was carried out at negative polarity. Then, the optimized method was validated in terms of linearity, accuracy and precision. Sweeping preconcentration of linezolid provides detection limit at 0.05μg/ml level. The evaluated CE method was applied in the analysis of medicinal product containing linezolid–linezolid solution for infusion. [Copyright &y& Elsevier]

Abstract: A method for the enantioseparation of linezolid, the first compound of a truly new class of antibiotics—the oxazolidinones, was developed. The elaborated method of linezolid enantiomers separation was successfully performed using an anionic single-isomer cyclodextrin—heptakis-(2,3-diacetyl-6-sulfato)-β-cyclodextrin (HDAS-β-CD) as a resolving agent with the help of the charged resolving agent migration model (CHARM model). The best results were obtained with 27.5mM HDAS-β-CD dissolved in 50mM borate buffer, pH 9.0, 15°C, normal polarity. The facile strategies for the reversal of the enantiomers elution order are also described. Afterwards, the optimized method was validated in terms of sensitivity, linearity, accuracy and precision. [Copyright &y& Elsevier]

Abstract: The application of capillary electrophoresis for separation of penicillin V and its impurities was investigated. The phosphate–borate buffer supplemented with sodium dodecyl sulfate (SDS) 20.0g/L (69mM) and pentanesulfonic acid sodium salt (PS) 2.2g/L (12.5mM) adjusted to pH 6.3, and current voltage 15kV seem to provide optimal conditions for this aim. The resolution between penicillin V and each impurity was very good. The statistical analysis of phenoxymethylpenicillin V assay showed no significant differences between the results obtained by CE and HPLC methods. [Copyright &y& Elsevier]

Capillary zone electrophoresis (CZE) has been elaborated for separation, identification and determination of ciprofloxacin and its impurities. The separation, phosphate buffer pH 6.0 was supplemented with 0.075 M pentane-1-sulfonic acid sodium salt. The elaborated method was validated. The selectivity, linearity, limits of detection (LOD) and quantification (LOQ), precision, and accuracy of capillary zone electrophoresis were evaluated. The results obtained by CZE were also compared with those obtained by liquid chromatography. Regarding the validation results the CE method fulfils the current European Pharmacopoeia (Eur. Ph.) requirements. The evaluated CE method could be applicable to the analysis of different medicinal products containing ciprofloxacin. [Copyright &y& Elsevier]

The application of capillary electrophoresis for separation of benzylpenicillin, procaine, benzathine and clemizole was investigated. Phosphate–borate buffer supplemented with sodium dodecyl sulphate 14.4 g/l and electrophoresis voltage 18 kV seem to provide optimal conditions for micellar electrokinetic chromatographic assay of penicillin salts. This method is selective and precise. The results obtained from CE method recovery assay (above 98% for all but procaine—97% substances) and from determination of benzylpenicillin by CE compared with HPLC results, confirmed good accuracy. [Copyright &y& Elsevier]

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 tcalculated 0.32 and 1.69 for amoxicillin and clavulanic acid and 0.67 and 1.93 for ampicillin and sulbactam were smaller than ttabulated. [Copyright &y& Elsevier]

Ceftaroline fosamil, the prodrug of ceftaroline, is an advanced-generation cephalosporin antibacterial agent approved for treatment in the European Union in 2012. The drug is dedicated to curing complicated skin and soft tissue infections and community-acquired pneumonia. The developed analytical method of high performance liquid chromatography (HPLC) followed by diode array detector (DAD) set at 243 nm was used to identify and determine degradation products of ceftaroline fosamil. The elaborated method demonstrated good selectivity and linearity [r > 0.998 for the range 0.8–1.2 mg/mL (80–120%) and r > 0.997 for the range 0.005–0.015 mg/mL (0.5–1.5%)]. Limit of detection (LOD) and limit of quantification (LOQ) values were equal to 0.15 μg/mL and 0.5 μg/mL, respectively. The forced decomposition of ceftaroline fosamil carried out under acidic, basic, oxidative, photolytic and thermal conditions revealed the high sensitivity of ceftaroline on photodegradation and thermolysis processes. Representative ceftaroline samples were selected and analysed by LC coupled with electrospray ionisation time-of-flight mass spectrometry (LC-ESI-Q-TOF-MS) to identify the related substances that appeared under stress conditions. The LC-DAD method was transferred without any modification to LC–MS/MS system, allowing it to correlate results back to the LC-DAD method. Eight unknown signals were detected in the photolytic and thermal stress solutions for ceftaroline fosamil. The evaluated method was applied to the analysis of a medicinal product containing ceftaroline fosamil − Zinforo™, 600 mg, powder for concentrate for solution for infusion. Moreover, the optimised conditions allowed for the successful separation of eight cephalosporin antibiotics possessing a molecular structure similar to ceftaroline (cefepime, cefapirin, ceftazidime, cefpirome, cefalonium, cefotaxime, cefquinome, cefalotin). [ABSTRACT FROM AUTHOR]

Abstract: The elaborated method of micellar electrokinetic chromatography (MEKC) used to separate biapenem from its related substances was successfully implemented using sweeping under an enhanced electric field, followed by UV absorption detection at 200nm. The best results were obtained with formic buffer (22.5mM) pH 4.3 and sodium dodecyl sulfate (150mM) added to the electrolyte as the sweeping agent. Neutral capillary (60/50cm; 50μm ID) with reverse polarity and voltage values of 22kV, were used throughout the investigation. The optimized method of biapenem determination, validated in terms of linearity, accuracy and precision, provides a detection limit of 0.5μg/mL at S/N=3 for biapenem. The repeatability of the CE system, expressed by relative standard deviations (RSD) in the migration times, for biapenem and its degradation products varied from 0.14 to 1.48%, whereas for the corrected peak areas RSD were about 0.68–8.43%. Satisfactory separation was achieved within 20min of electrophoresis; moreover all carbapenems (imipenem, meropenem, ertapenem, doripenem and biapenem) were separated from each other during analysis. The evaluated MEKC method was applied to the analysis of a medicinal product containing biapenem – Omegacin® 0.3g for intravenous drip infusion. [Copyright &y& Elsevier]