Simultaneous Determination of Dexrabeprazole and Domperidone in Capsule Form by Using Hptlc and Mass Confirmation by Hptlc-ms

A rapid, quantitative and optimised high-performance thin-layer chromatographic method coupled to mass spectrometry using electro spray ionization (HPTLC/ESI-MS) for the separation and quantification of dexrabeprazole and domperidone in combined capsule dosage form has been developed and validated. The formulations were separated on silica gel 60 F254 plates using a saturated mixture of toluene: ethyl acetate: methanol (6:5:2 v/v). Densitometric quantification was performed at 285 nm by reflectance scanning and the retention factors for dexrabeprazole and domperidone were found to be 0.53±0.02 and 0.43±0.02. The detector response was linear in the concentration range of 50-500 ng/band for both dexrabeprazole and domperidone with a regression coefficient(r) of 0.9993 and 0.9990. Recoveries of spiked samples at three levels ranged from 99.55 to 101.8% dexrabeprazole and 99.37 to 100.8% for domperidone the validated lowest limit of detection and quantification were 21.22 ng/band and 16.95 ng/band and 70.73 ng/band and 56.51 ng/band for dexrabeprazole and domperidone respectively. The Selectivity was evaluated determining the peak purity by UV-spectrophotometry. Additionally the peak identities as well as the purities were confirmed by mass spectrometry. The ESI+ mass spectra showed the [M +H]+ ions for dexrabeprazole and domperidone detected at m/z 360.3 and 426.8 being acquired directly from the sample bands by an elution-based interface. This simple, yet a reliable planar chromatographic method with less elaborate sample preparation, enhanced separation efficiency with an online confirmation by MS offers a good alternative for the analysis of pharmaceutical formulations.