Evaluation of newly synthesized derivative of cyclodextrin for the capillary electrophoretic separation

Emerging Developments in Separation Techniques and Analysis of Chiral Pharmaceuticals

Chiral separation, the process of isolating enantiomers from a racemic mixture, holds paramount importance in diverse scientific disciplines. Using chiral separation methods like chromatography and electrophoresis, enantiomers can be isolated and characterized. This study emphasizes the significance of chiral separation in drug development, quality control, environmental analysis, and chemical synthesis, facilitating improved therapeutic outcomes, regulatory compliance, and enhanced industrial processes. Capillary electrophoresis (CE) has emerged as a powerful technique for the analysis of chiral drugs. This review also highlights the significance of CE in chiral drug analysis, emphasizing its high separation efficiency, rapid analysis times, and compatibility with other detection techniques. High-performance liquid chromatography (HPLC) has become a vital technique for chiral drugs analysis. Through the utilization of a chiral stationary phase, HPLC separates enantiomers based on their differential interactions, allowing for the quantification of individual enantiomeric concentrations. This study also emphasizes the significance of HPLC in chiral drug analysis, highlighting its excellent resolution, sensitivity, and applicability. The resolution and enantiomeric analysis of nonsteroidal anti-inflammatory drugs (NSAIDs) hold great importance due to their chiral nature and potential variations in pharmacological effects. Several studies have emphasized the significance of resolving and analyzing the enantiomers of NSAIDs. Enantiomeric analysis provides critical insights into the pharmacokinetics, pharmacodynamics, and potential interactions of NSAIDs, aiding in drug design, optimization, and personalized medicine for improved therapeutic outcomes and patient safety. Microfluidics systems have revolutionized chiral separation, offering miniaturization, precise fluid control, and high throughput. Integration of microscale channels and techniques provides a promising platform for on-chip chiral analysis in pharmaceuticals and analytical chemistry. Their applications in techniques such as high-performance liquid chromatography (HPLC) and capillary electrochromatography (CEC) offer improved resolution and faster analysis times, making them valuable tools for enantiomeric analysis in pharmaceutical, environmental, and biomedical research.

Chiral separations by CE employing CDs

This paper summarizes the history of chiral separations done by using electromigration methods with CDs. Several enantioresolution mechanisms and a wide number of chiral selectors have been applied to the separation of optical isomers by CE. Among them inclusion-complexation with CDs or their derivatives played a very important role in CE. Since the beginning our group was involved in studying method optimization for enantiomer resolution by using these chiral selectors. One of our publications was the basis for further development in the field, at least for us. New chiral selectors, development of theory, new methodological approaches and a wide number of practical applications are the main results achieved in the last almost 25 years using CE as an enantioseparative technique.

Recent advances in the methodology, optimisation and application of MEEKC

MEEKC is an electrodriven separation technique. Oil-in-water microemulsions (MEs) and to a lesser extent water-in-oil MEs have been used in MEEKC as BGEs to achieve separation of a diverse range of solutes. The more common (oil-in-water) MEs are composed of nanometre-sized droplets of oil suspended in an aqueous buffer. Interfacial tension between the oil and aqueous phase is reduced close to zero by the presence of a surfactant and a co-surfactant. MEEKC is capable of providing fast and efficient separations for a wide range of acidic, basic and neutral, water-soluble and -insoluble compounds. This review details the advances in MEEKC-based separations from the period 2006 to 2008. Areas covered include online sample concentration, chiral separation, suppressed electroosmosis MEEKC, MEEKC-MS, and the use of MEEKC in predicting migration behaviour and solute characteristics. A fundamental introduction to MEEKC, along with the presentation and discussion of recent applications is also included.

Investigation of β-CD-derivatized erythromycin as chiral selector in CE

A novel water-soluble beta-CD-derivatized erythromycin (EM) was synthesized and used as an effective chiral selector for the resolution of chiral compounds in CZE. The purpose of substitution at the primary hydroxyl site of beta-CD with 1-oxygen-2,3-epoxypropane is to produce a compound having functions of both beta-CD and EM. beta-CD-derivatized EM exhibited excellent enantioselectivities compared with single beta-CD and EM for chiral separation in CE. We also investigated the influence of pH and concentration of BGE, concentration of chiral selector, applied potential, and organic modifier on chiral compounds' separation.

Chiral separations by capillary electrophoresis: Recent developments and applications

This paper provides an overview of the different classes of chiral selectors that are used in CE. The main properties of every class are described, together with the mechanism of enantioseparation. Newly introduced selectors are also discussed. Pharmaceutical and biomedical applications published from January 2004 till March 2005 are summarized.

Recent advances in pharmaceutical applications of chiral capillary electrophoresis

This review article summarizes developments and applications of chiral capillary electrophoresis (CE) in the pharmaceutical field published from January 2004 to June 2005. Due to the tremendous number of publications, this article is aimed to focus on major developments in chiral separations and some selected applications rather than to provide a descriptive overview of all published papers. Valuable information is also collected from several excellent reviews published during this period. Developments are classified according to CE modes, namely capillary zone electrophoresis (CZE), micellar electrokinetic capillary chromatography (MEKC), microemulsion electrokinetic chromatography (MEEKC). In the CZE section, different types of chiral selectors including cyclodextrins, oligo- and polysaccharides, crown ethers, macrocyclic antibiotics, ligand exchange systems and proteins are described. Nonaqueous capillary electrophoresis is also included in this section. Coupling CE to MS is discussed in a separate part, followed by a summary of selected pharmaceutical applications of enantioselective CE. Finally, some conclusions are drawn and prospects of CE in chiral analysis are also drafted.

Capillary zone electrophoretic chiral discrimination using 6-O-(2-hydroxy-3-trimethylammoniopropyl)-β-cyclodextrin as a chiral selector

A charged highly water-soluble CD derivative, 6-O-(2-hydroxy-3-trimethylammoniopropyl)-beta-CD (herein noted as 6-HPTMA-beta-CD) was synthesized and successfully used as a chiral selector for enantiomeric separation of some acidic compounds by CZE in an uncoated capillary. Substitution with 2-hydroxy-3-trimethylammoniopropyl groups at the primary hydroxyl group of the CD was aimed at influencing the magnitude and selectivity of analyte-CD interactions. The behavior of 6-HPTMA-beta-CD was compared with that of the commercially available quaternary ammonium-beta-CD (QA-beta-CD) under the same separating conditions. The experiments were carried out using a BGE consisting of 50 mM phosphate in the pH range of 4-6 by adding a relatively low concentration of chiral selector (less than 10 mM). The effects of the concentration of CD and the pH of the electrolyte on the resolution of these compounds were studied.

Chiral separation of salbutamol and bupivacaine by capillary electrophoresis using dual neutral cyclodextrins as selectors and its application to pharmaceutical preparations and rat blood samples assay

An attempt for the simultaneous separation of salbutamol (Sal) and bupivacaine (Bup) enantiomers was performed by capillary elecytrophoresis with a dual mixture of neutral cyclodextrins as chiral selector. The influence on the separation of several parameters such as buffer composition, pH, the concentration ratio of 2-hydroxypropyl-beta-cyclodextrin (HP-beta-CD) to dimethyl-beta-cyclodextrin (DM-beta-CD) was investigated. A better separation was obtained for Sal and Bup with the CD mixtures compared to the use of HP-beta-CD or DM-beta-CD alone. The best simultaneous separation of Sal and Bup enantiomers was achieved with a 20 mM HP-beta-CD and 20 mM DM-beta-CD at pH 2.5 in a triethanolamine (TEA)/phosphate buffer. This method-utilized chlorphenamine (Chl) as an internal standard was found to be linear in the range 0.5-100 microg/mL and 0.5-150 microg/mL for Sal and Bup enantiomers, respectively. The limits of detection for both enantiomers of Sal and Bup were 0.18 and 0.24 microg/mL, respectively. The proposed method was applied to monitor Sal and Bup enantiomers concentration change in rat blood samples obtained from a male rat after celiac doses administration 0-30 min of Sal and Bup racemate. The method could also be used to determine Sal enantiomers in a pharmaceutical aerosol.

Enantioseparation in capillary electrophoresis using 2-O-(2-hydroxybutyl)-β-CD as a chiral selector

The resolving ability of 2-O-(2-hydroxybutyl)-beta-CD (HB-beta-CD) with different degrees of substitution (DS = 2.9 and 4.0) as a chiral selector in CZE is reported in this work. Fourteen chiral drugs belonging to different classes of compounds of pharmaceutical interest such as beta-agonists, antifungal agents, ageneric agents, etc., were resolved. The effects of the DS of HB-beta-CD on separations were also investigated. The chiral resolution (R(s)) was strongly influenced by the concentrations of the CD derivative, the BGE, and the pH of the BGE. Under the conditions of 50 mmol/L Tris-phosphate buffer at pH 2.5 containing 5 mmol/L HB-beta-CD, all 14 analytes were separated. The very low concentration necessary to obtain separation was particularly impressive. The DS had a significant effect on the resolution of the chiral drugs and the ionic strength of the separation media; hence, the use of a well-characterized CD derivative is crucial.

Determination of saikosaponins a, c, and d in Bupleurum Chinese DC from different areas by capillary zone electrophoresis

A fast capillary zone electrophoresis (CZE) method was developed for the determination and separation of saikosaponins a, c, and d in Chinese herbal extracts of Bupleurum Chinese DC from different areas. Detection at 214 nm with a system containing sodium borate buffer and mono-3-phenylcarbamoyl-beta-CD was found to be the most suitable approach for this analysis. Saikosaponins a, c, and d could be easily determined within 8 min. The effect of the concentration of mono-3-phenylcarbamoyl-beta-CD, the concentration of the running buffer and buffer pH value on the migration behavior of the saikosaponins is discussed.