Enantiomeric determination of econazole and sulconazole by electrokinetic chromatography using hydroxypropyl-b-cyclodextrin combined with ionic liquids based on L-lysine and Ly-glutamic acid

Two analytical methodologies based on the combined use of hydroxypropyl-beta-cyclodextrin and two different amino acid-based chiral ionic liquids (tetrabutylammonium-L-lysine or tetrabutylammonium-L-glutamic acid) in electrokinetic chromatography were developed in this work to perform the enantios-elective determination of econazole and sulconazole in pharmaceutical formulations. The influence of different experimental variables such as buffer concentration, applied voltage, nature and concentration of the ionic liquid, temperature and injection time, on the enantiomeric separation was investigated. The combination of hydroxypropyl-beta-cyclodextrin and tetrabutylammonium-L-lysine under the optimized conditions enabled to achieve the enantiomeric determination of both drugs with high enantiomeric resolution (3.5 for econazole and 2.4 for sulconazole). The analytical characteristics of the developed methodologies were evaluated in terms of linearity, precision, LOD, LOQ and recovery showing good performance for the determination of both drugs which were successfully quantitated in pharmaceutical formulations. This work reports the first analytical methodology enabling the enantiomeric determination of sulconazole in pharmaceutical formulations

A chiral electrokinetic chromatography method for the separation and quantitation of licarbazepine and licarbazepine acetate in pharmaceutical formulations and urine samples

S-Licarbazepine acetate is a new antiepileptic that is quickly metabolized to S-licarbazepine which is the active principle. In this study, an enantioselective methoddology enabling the simultaneous separation of licarbazepine acetate and licarbazepine by Electrokinetic Chromatography has been developed for the first time. After evaluating the potential of different chiral selectors, including bile salts and cyclodextrins, and selecting carboxymethyl-?-cyclodextrin as the most appropriate, a Box-Behnken experimental design was effectively applied for the optimization of the experimental separation conditions. Employing the best conditions, the four enantiomers were simultaneously separated (resolution values > 2.4) in less than 7 min. The evaluation of the figures of merit of the developed methodology showed to be suitable to determine both compounds. Finally, the EKC method was successfully applied in three different studies: (i) the quality control of the enantiopure pharmaceutical formulation, (ii) the monitoring of the stability and gastrointestinal digestion of the pharmaceutical formulation through a hydrolysis study, and (iii) the determination of licOH enantiomers in urine samples

Advances in the determination of non-protein amino acids in foods and biological samples by capillary electrophoresis

There are hundreds of non-protein amino acids whose importance in food and biological matrices is still unknown. Many of these compounds mainly exist in food as products formed during food processing, as metabolic intermediates or as additives to increase nutritional and functional properties of food. Moreover, they have also demonstrated to play an important role in the pharmaceutical and clinical fields since they may be used therapeutically in the treatment of some pathologies and their levels may be related with some diseases. For this reason, the analysis of non-protein amino acids may provide relevant information in the food and biological fields. This article reviews the most recent advances in the development of analytical methodologies employing capillary electrophoresis for the achiral and chiral analysis of non-protein amino acids in food and biological samples. With this aim, the most relevant information concerning the separation and detection of these compounds by capillary electrophoresis is discussed and detailed experimental conditions under which their determination was achieved in food and biological samples are given covering the period of time from 2015 to 2018

Amino acid chiral ionic liquids combined with hydroxypropyl-beta-cyclodextrin for drug enantioseparation by capillary electrophoresis

Four amino acid chiral ionic liquids were evaluated in dual systems with hydroxypropyl-beta-cyclodextrin to investigate the enantioseparation by CE of a group of seven drugs as model compounds (duloxetine, verapamil, terbutaline, econazole, sulconazole, metoprolol, and nadolol). The use of two of these chiral ionic liquids (tetramethylammonium L-Lysine ([TMA][L-Lys]) and tetramethylammonium L-glutamic acid ([TMA][L-Glu]) as modifiers in CE is reported for the first time in this work whereas tetrabutylammonium L-lysine [TBA][L-Lys]) and tetrabutylammonium L-glutamic acid ([TBA][L-Glu]) were employed previously in CE although very scarcely. The effect of the nature and the concentration of each ionic liquid added to the separation buffer containing the neutral cyclodextrin on the enantiomeric resolution and the migration time obtained for each drug, was investigated. A synergistic effect was observed when combining each chiral ionic liquid with hydroxypropyl-beta-cyclodextrin in the case of the five compounds for which the cyclodextrin showed enantiomeric discrimination power when used as sole chiral selector (duloxetine, verapamil, terbutaline, econazole, sulconazole). Buffer concentration and pH, temperature and separation voltage were varied in order to optimize the enantiomeric separation of these five compounds using dual systems giving rise to resolutions ranging from 1.1 to 6.6. (C) 2019 Elsevier B.V. All rights reserved