A novel and simple dynamic coating capillary electrophoresis method for the chiral separation and quantification of mitiglinide enantiomers using hydroxyethyl cellulose as a dynamic coating agent.

Abstract

A capillary electrophoretic method for the chiral separation and quantification of mitiglinide (MTG) enantiomers is described (less than 9.5 min) with resolution value Rs = 5.25 and with excellent peak shapes after performing the dynamically coating for the bare fused capillary. The study aims to develop and validate a novel and simple method for the separation and quantification of MTG enantiomers using CE after dynamic coating the capillary wall using the hydroxyethyl cellulose (HEC) coating agent. Dynamic coating procedure of the capillary inner surface is conducted via rapid flushes using 0.1 M sodium hydroxide, water, and aqueous solution containing HEC, and hydroxypropyl-γ-cyclodextrin (HP-γ-CD). Besides buffer was used for the dynamic coating process in addition to its use as the separation medium. When the dynamic coating was used, peak symmetry was improved. A bare fused-silica capillary was used throughout the separation after being coated using HEC dissolved in the background electrolyte (BGE) of 50 mM Na₂HPO₄ - 1 M H₃PO₄ solution; pH 8.5; containing 25 25 mg mL-1 of each HP-γ-CD and HEC. The dynamic coating procedure achieved an improvement in migration time as well as peak area precision. The adsorbed coating agent showed slight interactions with MTG, providing efficient separation with outstanding durability and reproducibility at slightly alkaline conditions (pH 8.5). Acceptable validation criteria for selectivity, linearity, precision, and accuracy were also studied. The newly developed method was effectively applied to the assay of enantiomers of MTG in pharmaceutical formulations. Additionally, it was proven to have the advantages of being simple, rapid, and accurate.