HPLC Determination of Roflumilast and 4 Impurities in Roflumilast Drug

HPLC was applied to the determination of Roflumilast and 4 impurities in Roflumilast drug.The sample was dissolved with acetonitrile.Welch Ultimate XB-C18 chromatographic column was used as stationary phase,and a mixture of 0.01 mol·L-1 K2HPO4 solution (adjusted pH to 4 with phosphoric acid) and acetonitrile (50+50) was used as mobile phase.UV-detection at 215 nm was adopted in the determination.Linear relationships between values of peak area and mass concentration of Roflumilast and the 4 impurities were kept in definite ranges.Low limits of determination (10S/N) found were ranged from 0.04 to 0.22 ng.Values of recovery found by standard addition method were in the range of 101%-102%,and values of RSD′s (n=9) less than 2.0%.