Evaluation of the enantioselective binding of imazalil to human serum albumin by capillary electrophoresis.

In this work, a methodology for the evaluation of enantioselective binding of imazalil (IMA) enantiomers to human serum albumin (HSA) that does not require the separation of free and bound to HSA fractions is developed. This methodology comprises the incubation of IMA-HSA designed mixtures for 30 min directly in the capillary electrophoresis system and the subsequent direct injection and chiral separation of IMA employing highly sulfated β-cyclodextrin as chiral selector and the complete filling technique. Two mathematical approaches were used to estimate apparent affinity constants (K1), protein binding and enantioselectivity (ES) for both enantiomers of IMA.

Chiral separations by non-aqueous capillary electrophoresis in DMSO-based background electrolytes.

Capillary electrophoresis (CE) is a powerful technique for enantioseparations due to its high separation efficiency, high versatility, speed of analysis and low consumption of samples and reagents. Non-aqueous capillary electrophoresis (NACE) appears as a promising technique to perform enantioseparations when the drugs, chiral selectors or samples are non-water soluble. Chiral separations have been performed by NACE mainly using alcoholic solvents as BGEs, with problems of current breakdowns and changes in the BGE composition, due to their high volatility.

Fast evaluation of enantioselective drug metabolism by electrophoretically mediated microanalysis: application to fluoxetine metabolism by CYP2D6.

In this work, a capillary electrophoretic methodology for the enantioselective in vitro evaluation of drugs metabolism is applied to the evaluation of fluoxetine (FLX) metabolism by cytochrome 2D6 (CYP2D6). This methodology comprises the in-capillary enzymatic reaction and the chiral separation of FLX and its major metabolite, norfluoxetine enantiomers employing highly sulfated β-CD and the partial filling technique. The methodology employed in this work is a fast way to obtain a first approach of the enantioselective in vitro metabolism of racemic drugs, with the additional advantage of an extremely low consumption of enzymes, CDs and all the reagents involved in the process.

Modeling the chiral resolution ability of highly sulfated β-cyclodextrin for basic compounds in electrokinetic chromatography.

Despite the fact that extensive research in the field of enantioseparations by capillary electrophoresis has been carried out, it is difficult to predict whether a concrete chiral selector would be useful for the separation of a racemic compound. Hence, several experimental effort is necessary to test the abilities of individual chiral selectors, usually by trial and error procedures. Thus, the enantioseparation of a new racemate becomes a time- and money-consuming task.

In-line capillary electrophoretic evaluation of the enantioselective metabolism of verapamil by cytochrome P3A4.

In this paper a methodology for the in-line evaluation of enantioselective metabolism by capillary electrophoresis has been developed and applied to the study of verapamil metabolism by cytochrome P3A4. The developed methodology comprises an in-capillary reaction step carried out by electrophoretically mediated microanalysis and a separation step in which highly sulfated β-cyclodextrin with partial filling technique has been employed as chiral selector for verapamil and norverapamil enantiomers resolution, joining the advantages of both methodologies in a unique assay. Kinetic parameters of the enzymatic reaction (Km and Vmax) have been evaluated for both verapamil enantiomers by non-linear fitting of experimental data obtained under intermediate precision conditions to Michaelis-Menten equation.