Determination of artemether and lumefantrine in anti-malarial fixed-dose combination tablets by microemulsion electrokinetic chromatography with short-end injection procedure.

Background: Artemether-lumefantrine (AL) combination therapy is now the most used anti-malarial treatment in the world. Quality control of AL formulations is still a major challenge in developing countries. Until now, only liquid chromatographic methods have been reported in the literature for their analysis.

Capillary electrophoresis methods for the analysis of antimalarials. Part II. Achiral separative methods.

An exhaustive review of applications of achiral capillary electrophoresis methods to the analysis of antimalarials is presented. It covers quality control of formulations, analysis in biological fluids and food, determination of physico-chemical properties (pKa, partition coefficient and interaction studies). Miscellaneous applications are also considered.

Capillary electrophoresis methods for the analysis of antimalarials. Part I. Chiral separation methods.

This paper presents an overview on the current status of enantiomeric and diastereomeric separations of chiral antimalarials and derivatives by capillary electrophoresis (CE). The wide variety of chiral selectors which have been employed to resolve successfully antimalarial enantiomers: oligosaccharides (cyclodextrins, oligomaltodextrins), neutral (amylose, dextrin and dextran) and charged (chondroitin sulfate, heparin, dextran sulfate) polysaccharides and proteins are reviewed. Cyclodextrins were the most employed.

Capillary electrophoresis for the assay of fixed-dose combination tablets of artesunate and amodiaquine.

Background: Quality control of drugs in formulations is still a major challenge in developing countries. For the quality control of artesunate and amodiaquine tablets in fixed-dose combination, only liquid chromatographic methods have been proposed in the literature. There are no capillary electrophoretic methods reported for the determination of these active substances, although this technique presents several advantages over liquid chromatography (long lifetime, low price of the capillary, low volumes of electrolyte consumption) in addition to simplicity.

Capillary zone electrophoresis as a potential technique for the simultaneous determination of sulfadoxine and pyrimethamine in tablet formulations.

A novel, simple and rapid capillary zone electrophoresis method with UV detection has been developed for the simultaneous determination of pyrimethamine and sulfadoxine in tablet formulations. The compounds are separated in 6 min in a fused silica capillary, 30 cm long (20 cm to detector)× 50 μm using a 100 mM phosphate buffer pH 7.2 as background electrolyte, a 330 V cm(-1) electric field and a detection wavelength of 214 nm.

Stability of capillaries coated with highly charged polyelectrolyte monolayers and multilayers under various analytical conditions--application to protein analysis.

The stability of capillaries coated with highly charged polyelectrolytes under various analytical conditions was studied, as well as their performance for the analysis of proteins by Capillary Electrophoreis (CE) over a wide range of pH (2.5-9.3).

Use of coated capillaries for the electrophoretic separation of stereoisomers of a growth hormone secretagogue.

The diastereoisomeric separation of peptidomimetics of hexarelin, a strong growth hormone secretagogue, in CE has been studied. Highly sulfated-gamma-CD was found to be an appropriate selector for the separation of the stereoisomers. However, non-repeatable analyses were obtained on bare fused silica capillary due to the progressive adsorption of the analytes on the capillary wall.

Influence of polyelectrolyte capillary coating conditions on protein analysis in CE.

CE of biomolecules is limited by analyte adsorption on the capillary wall. To prevent this, monolayer or successive multiple ionic-polymer layers (SMILs) of highly charged polyelectrolytes can be physically adsorbed on the inner capillary surface. Although these coatings have become commonly used in CE, no systematic investigation of their performance under different coating conditions has been carried out so far.

Influence of polyelectrolyte coating conditions on capillary coating stability and separation efficiency in capillary electrophoresis.

Polyelectrolytes are widely used in capillary electrophoresis as coating agents of silica capillaries to prevent adsorption phenomena and improve the repeatability of peptide and protein analysis. A systematic study of the coating experimental conditions has been carried out to optimize coating stability and performance. The main experimental parameters studied were the type and concentration of polyelectrolytes used in several monolayer and multilayer coatings, the ionic strength of coating and stabilizing solutions, and the procedures used for coating and capillary storage.

LIF detection of peptides and proteins in CE.

CE- and microchip-based separations coupled with LIF are powerful tools for the separation, detection and determination of biomolecules. CE with certain configurations has the potential to detect a small number of molecules or even a single molecule, thanks to the high spatial coherence of the laser source which permits the excitation of very small sample volumes with high efficiency. This review article discusses the use of LIF detection for the analysis of peptides and proteins in CE.

Precision study on capillary electrophoresis methods for metacycline.

A CE method for metacycline (MTC) determination was investigated in an inter-laboratory experiment. Many problems were encountered in this study, most of which were related to the transfer of the method to different CE equipment. The reported problems could be classified into different categories: problems related to the precision, to the parameters in the protocol, and to the MTC peak shape.

Separation of 3'-azido-2',3'-dideoxythymidine pronucleotide diastereoisomers in biological samples by CZE with cyclodextrin addition.

The possibility of using capillary electrophoresis as an alternative technique to HPLC for the separation of pronucleotide diastereoisomers of AZT was investigated. In the pH range 6.2-7.

Robustness testing of chiral separations by capillary electrophoresis using highly-sulfated cyclodextrins.

The robustness of a generic method for chiral separation in capillary electrophoresis using highly-sulfated cyclodextrins in a low pH phosphate buffer and the "short-end injection technique" was studied. In this study, we focused on the robustness of the separations and not of the quantitative analysis of the enantiomers. The robustness was evaluated for the enantiomeric separation of a basic (propranolol), a neutral (praziquantel) and an acidic (warfarin) compound.

Influence of peak measurement parameters on the quality of chiral electrophoretic separations.

The effect of nine peak measurement/analysis parameters on chiral capillary electrophoresis (CE), followed by UV detection, was studied. The parameters pertained UV-detection (detection wavelength, reference wavelength, and wavelength bandwidths), signal processing (data acquisition rate, type and amount of filtering) and peak detection (detection threshold and peak width). The influence of these factors on the chiral separation of dimethindene enantiomers was studied at two different concentrations (i.