Determination of desloratadine in drug substance and pharmaceutical preparations by liquid chromatography

A simple and selective LC method is described for the determination of desloratadine in drug substance and pharmaceutical preparations. Chromatographic separation was achieved on a Diamonsil BDS C₁₈ column using a mobile phase of a mixture of methanol, 0.03 mol/l heptanesulphonic acid sodium and glacial acetic acid (70:30:4, v/v) at a flow rate of 1.0 ml/min with detection at 247 nm. The developed method was validated in terms of selectivity, linearity, limit of quantitation, precision, accuracy and solution stability. The proposed LC method achieved satisfactory resolution between desloratadine and loratadine possibly present in desloratadine drug substance and other impurities in the mother liquor of the synthetic process. It can be used for the synthetic process control and determination of desloratadine in drug substance and pharmaceutical preparations.