A simple, precise and accurate method is validated for the simultaneous determination of two nitrogenous compounds dextromethorphan hydrobromide and promethazine hydro-chloride, which are commonly used as active ingredients in pharmaceutical syrups. The chromatographic conditions comprised of a classical C8-type stationary phase (250 × 4.6 mm, 5 μm) with a mobile phase consisting of 3 g of sodium lauryl sulfatein a mixture of 400 ml of water and 600 ml of acetonitrile along with 0.5 g of ammonium nitrate as additional agent. The solution pH 2.0 was adjusted with glacial acetic acid. The flow rate was 1 ml/min; the detection was carried out at 280 nm under temperature of 25o. The retention time of dextromethorphan was 8.5 min and 9.9 min for promethazine. The method was validated for specificity, accuracy, precision and linearity. The results indicate that the drugs are susceptible to photo-degradation. All the peaks of degraded products were resolved from the two active pharmaceutical ingredients with significant different retention times.
International Journal of Pharmaceutical Sciences and Nanotechnology(IJPSN).
2015.
