Enantioselective determination of pheniramine in pharmaceuticals by capillary electrophoresis with charged cyclodextrin

Cyclodextrin (CD)-mediated capillary zone electrophoresis (CZE) in hydrodynamically closed separation system was developed for the separation and quantitation of pheniramine (PHM) enantiomers. Several parameters affecting the separation were studied, including the type and concentration of chiral selector, carrier cation and counterion, and the pH of the buffer. A high effectivity of oppositely migrating carboxyethyl-β-cyclodextrin (CE-β-CD) to separate the PHM enantiomers was demonstrated in detail. The optimized chiral analysis of the antihistamine drug was performed in a buffer consisted of 20 mmol/l ɛ-aminocaproic acid adjusted to pH 4.5 with acetic acid, containing negatively charged CE-β-CD (2.5 mg/ml) as chiral selector and 0.2% (w/v) methylhydroxyethylcellulose (m-HEC) as an electro-osmotic flow (EOF) suppressor. Acceptable validation criteria for sensitivity, linearity, precision, accuracy/recovery were included. The proposed CZE method was successfully applied to the assay of PHM in pharmaceutical formulations using dioxopromethazine as an internal standard.