RESUMEN
Capillary isotachophoresis was employed to separate and determine dimethinden enantiomers in various dosage forms. Several types of chiral selectors were tested in various electrolyte systems of different composition and different pH. The optimal leading electrolyte was composed of 10 mmol/l potassium acetate and acetic acid to achieve pH 4.8 with an addition of 4 mmol/l carboxyethyl-beta-cyclodextrin as the chiral selector and 0.2% of methylhydroxyethylcellulose (m-HEC) to suppress the electroosmotic flow. The terminating electrolyte was betaalanine of a concentration of 5 mmol/l. The evaluation included the precision, correctness, linearity, robustness, and selectivity of the elaborated ITP method. The pretreatment of the sample prior to analysis consisted in the dissolution and dilution of the appropriate dimethinden-containing dosage form with demineralized water to achieve the required concentration. Such a pretreated sample was directly dosed into the apparatus.
Asunto(s)
Dimetindeno/química , Electroforesis Capilar , Antagonistas de los Receptores Histamínicos H1/química , EstereoisomerismoRESUMEN
Capillary isotachophoresis was employed to determine dimethindene in various dosage forms. Several electrolyte systems of varying compositions and varying pH were tested. For validation of the method and the determination of dimethindene in real samples (gel, drops, capsules), two electrolyte systems were selected. Precision, correctness, linearity, robustness, and selectivity of the ITP method were evaluated for both electrolyte systems. The pre-treatment of the sample prior to analysis consisted in dissolving and diluting the pertinent dosage form containing dimethindene with demineralized water to the required concentration. The sample adjusted in this way was directly dosed into the apparatus.