Development of a capillary electrophoresis method for the determination of orphenadrine citrate in tablets in the presence of paracetamol.

A validated method using capillary electrophoresis was developed, for the determination of orphenadrine citrate in its tablet formulations, in the presence of paracetamol. The method employs a running buffer of 30 mM pentane sulfonate sodium, dissolved in 20 mM MOPS buffer pH 7.7. Samples were injected using hydrodynamic sample injection mode (25 mbar, for 25 s), using positive polarity of 25 kV, at a constant temperature of 30 °C. Samples of orphenadrine citrate alone or in mixture solutions with paracetamol were exposed to various degradation conditions, and were electrophoresed using the recommended condition. The method was found to be specific, linear (r (2) = 0.994), precise, accurate, and robust, with an LOQ of 0.02 mg/mL. The proposed method was successfully applied for measurement of the percentage per label of orphenadrine citrate in commercially available tablets.