Determination of the enantiomeric impurity in S-(-)pantoprazole using high performance liquid chromatography with sulfobutylether-beta-cyclodextrin as chiral additive.

A new and accurate HPLC method using sulfobutylether-beta-cyclodextrin (SBE-beta-CD) as chiral mobile phase additive (CMPA) was developed and validated for the determination of R-(+)pantoprazole in S-(-)pantoprazole. The influences of type and concentration of CD, ACN content and buffer pH of mobile phase on the resolution and retention of enantiomers were investigated. A baseline resolution of pantoprazole enantiomers was achieved on a Spherigel C18 column (150 mm x 4.6 mm, 5 microm) using ACN and 10 mM phosphate buffer (pH 2.5) containing 10 mM SBE-beta-CD (15:85 v/v) as mobile phase with a flow rate of 0.9 mL/min at 20 degrees C. The detection wavelength was set at 290 nm. The method was extensively validated in terms of accuracy, precision and linearity according to the International Conference on Harmonisation (ICH) guidelines and proved to be robust. The LOD and LOQ for R-(+)pantoprazole were 0.2 and 0.5 microg/mL, respectively, with 5 microL injection volume. A good linear relationship was obtained in the concentration range of 0.5-6.0 microg/mL with r(2) >0.999 for R-(+)pantoprazole. The percentage recovery of the R-(+)pantoprazole ranged from 92.1 to 101.2 in bulk drug of S-(-)pantoprazole. The method is capable of determining a minimum limit of 0.05% w/w of R-enantiomer in S-(-)pantoprazole bulk samples.