Gradient HPLC analysis of raloxifene hydrochloride and its application to drug quality control

A rapid, sensitive and selective method for the determination of raloxifene hydrochloride (RLX) in pure drug and in tablets was developed using gradient high performance liquid chromatography (HPLC). The devised method involved separation of RLX on a reversed phase Hypersil ODS column and determination with UV detection at 284 nm. The standard curve was linear (R = 0.999) over the concentration range of 50--600 μg mL^-1 with a detection limit of 0.04 μg mL^-1 and a quantification limit of 0.16 μg mL^-1. Intra-day and inter-day precision and accuracy of the method were established according to the current ICH guidelines. Intra-day RSD values at three QC levels (250, 450 and 550 μg mL^-1) were 0.2--0.5%, based on the peak area. The intra-day relative error (e_r) was between 0.2 and 0.5%. The developed method was successfully applied to the determination of RLX in tablets and the results were statistically compared with those obtained by a literature method. Accuracy, evaluated by means of the spike recovery method, was the excellent with percent recovery in the range 97.7--103.2 with precision in the range 1.6--2.2%. No interference was observed from the co-formulated substances. The method was economical in terms of the time taken and the amount of solvent used.