Simultaneous determination of dexpanthenol, lidocaine hydrochloride, and mepyramine maleate in combined pharmaceutical gel by capillary electrophoresis

Abstract

A new capillary electrophoresis method was developed for the simultaneous determination of dexpanthenol (DEX), lidocaine (LID), and mepyramine (MEP) in pharmaceutical preparations. The best results were obtained using 20 mM (pH 3.0) phosphate buffer as the background electrolyte. Separation was obtained using a fused-silica capillary (75 μm internal diameter, 50 cm total length, 41 cm effective length) and a potential of +30 kV at 20 °C. Standards and samples were injected using a pressure injection at 50 mbar for 5 s and the analytes were monitored at a detection wavelength of 200 nm. Under optimum conditions, migration times were 2.457 min for MEP, 3.520 min for LID, and 7.363 min for DEX. The method was linear over the ranges of 25-200 μg mL-1for DEX, 7.5-60 μg mL-1for MEP, and 7.5-60 μg mL-1for LID. Limit of detection (LOD) values were 0.8 μg mL-1for MEP, 1.8 μg mL-1for LID, and 3.1 μg mL-1for DEX. The developed method is accurate, precise, sensitive, selective, and repeatable.