Simultaneous Chemo/Enantioseparation and Assay of R-(+)-Rabeprazole and Related Impurities in Pharmaceutical Formulations

Simultaneous chiral and chemoseparation of R-(+)-rabeprazole and related (enantio)impurities was achieved on a cellulose tris-(3,5-dichlorophenylcarbamate) stationary phase chemically bonded to silica gel (Chiralpak IC). A gradient elution was applied in the reverse-phase separation mode. The mobile phase consisted of a mixture of acetonitrile and aqueous phosphate buffer at pH 7. The other operational parameters were flow rate of 1 mL min⁻¹, column temperature of 35 °C and ultraviolet (UV) detection at 282 nm. Quantification limits for R-(+)-rabeprazole and the related impurities ranged in the interval of 0.02–0.03 %. Linear response intervals of 0.02–0.66 % were obtained with UV detection. Validation of the proposed method was achieved according to current regulations in force. For better understanding of the R-(+)-rabeprazole impurity profile, (+)-EMS/MS and MS/MS detection were also used.