The enantioselectivity of proton pump inhibitors, namely, omeprazole, lansoprazole, rabeprazole, pantoprazole, tenatoprazole, and ilaprazole were studied using new generation chiral packing materials: CHIRALPAK IA, CHIRALPAK IB, and CHIRALPAK IC. Two versatile techniques, HPLC and supercritical fluid chromatography (SFC) were used in this study. CHIRALPAK IC has shown superior selectivity under both LC and SFC conditions, whereas CHIRALPAK IA has shown good selectivity in SFC when compared to LC under primary screening conditions. The chiral recognition ability in LC and SFC modes were found to be in the order CHIRALPAK IC > CHIRALPAK IA > CHIRALPAK IB. In addition to diode array detection, chiral detection was carried out using a laser polarimeter and the elution orders were found to be the same in both LC and SFC elution modes. Mobile phase modifiers and column temperature effects were also studied. In SFC, modifiers (cosolvent) elution strength was found to be in the order ethanol > methanol > 2-propanol > acetonitrile. In both LC and SFC, a decrease in retention and increase in resolution with an increase in temperature was noticed for all the proton pump inhibitors.
Abstract:The chromatographic resolution of pregabalin enantiomers has been often achieved by derivatization of the molecule, in order to reach enough sensitivity at low concentrations of the minor enantiomer present in the active principle. In the present article, the development and optimization of two liquid chromatographic methods are presented for the direct resolution of pregabalin enantiomers on a chiral stationary phase (CSP) containing a zwitterionic selector derived from cinchona alkaloid and sulfonic acid (CHIRALPAK ZWIX). The key parameters for the separation as well as the compatibility of chromatographic conditions with different detection modes (ultraviolet and mass spectrometry) were investigated. The resulting methods were found to be selective, of high performance and low limits of detection (2 µg/mL by UV and 1 ng/mL by MS, respectively) and quantification (6 µg/mL by UV and 5 ng/mL by MS, respectively) for the minor enantiomer which is considered as a chiral impurity.
A selective, sensitive and robust chiral analytical method was developed for the quantification of Brivaracetam (BRV) and its three isomers. Systematic chiral chromatographic elution process was executed in different modes on chiral columns of polysaccharide based to attain the finest condition. The analytical method was developed by utilizing immobilized polysaccharide chiral column (CHIRALPAK IG-U) with reversed phase under isocratic condition containing acetonitrile and 10 mM ammonium bicarbonate in the proportion of 40:60 (v/v). The mobile phase flow rate and column temperature were monitored at 0.3 mLmin−1 and 25°C with a resolution of more than 2.0. The eluted components from the column were processed at 212 nm UV detection. The limit of detection and limit of quantification values of BRV, 2R, 4S-Isomer, 2R, 4R-Isomer and 2S, 4S-Isomers were found to be 0.0066/0.02, 0.0035/0.0107, 0.0036/0.0109 and 0.005/0.0152 µgml−1 respectively. Precision, linearity, accuracy and robustness were conducted according to ICH guidelines and the findings were within the acceptable limits. The proposed analytical method was found to be precise, accurate and specific for the quantification of enantiomer and its diastereomers for drug product and drug substance of BRV.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.