ABSTRACT
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.
Subject(s)
2-Pyridinylmethylsulfinylbenzimidazoles/isolation & purification , Anti-Ulcer Agents/isolation & purification , Chromatography, High Pressure Liquid/methods , beta-Cyclodextrins/chemistry , 2-Pyridinylmethylsulfinylbenzimidazoles/chemistry , Anti-Ulcer Agents/chemistry , Pantoprazole , Reference Standards , Reproducibility of Results , Sensitivity and Specificity , StereoisomerismABSTRACT
Vacomycin-bonded chiral stationary phase was used for the direct chiral separation of tenatoprazole enantiomers using reversed-phase high performance liquid chromatography (HPLC). The influences of the kinds and concentration of buffer and organic modifier, the pH value of buffer, column length and column temperature on the separation were examined. The chiral HPLC method for the separation of tenatoprazole enantiomers on a Chirobiotic V column (150 mm x 4.6 mm, 5 microm) was established with simplicity and good reproducibility using 0.02 mol/L ammonium acetate buffer (pH 6.0)-tetrahydrofuran (93:7, v/v) as the mobile phase at a flow rate of 0.5 mL/min and 20 degrees C. Under the above conditions, the enantiomers were separated on baseline with the resolution of 1.68. The relative standard deviations (RSDs) for the retention times of tenatoprazole enantiomers were 0.48% and 0.49% (n = 6). The RSDs for the peak areas of tenatoprazole enantiomers were 0.45% and 0.55% (n = 6).
Subject(s)
Chromatography, High Pressure Liquid/instrumentation , Chromatography, High Pressure Liquid/methods , Imidazoles/chemistry , Imidazoles/isolation & purification , Omeprazole/analogs & derivatives , 2-Pyridinylmethylsulfinylbenzimidazoles , Hydrogen-Ion Concentration , Molecular Structure , Omeprazole/chemistry , Omeprazole/isolation & purification , Reproducibility of Results , StereoisomerismABSTRACT
Enantioseparation of the Mannich ketone M9, a potential antifungal compound, was examined using chiral ligand-exchange chromatography. The chiral mobile phase contained complexes of Cu(II) with the optically active selector L-aspartame (APM) and the organic modifier methanol. The separation was optimized with respect to the concentration of the Cu(II)-(L-APM) complexes, pH of mobile phase, methanol content, and column temperature. A baseline separation (R(s) = 3.08) was achieved for enantiomers of M9 under optimal conditions, and the analysis was accomplished in eleven minutes. The developed method was extensively validated. The sample stability, linearity, precision (method repeatability and intermediate precision) and accuracy, and the limits of detection and quantification of the developed method were studied. The proposed method was shown to be accurate and suitable for the quantitative determination of each enantiomer of M9.
Subject(s)
Chemistry Techniques, Analytical/methods , Chromatography/methods , Ketones/chemistry , Antifungal Agents/pharmacology , Aspartame/analysis , Copper/chemistry , Ethanol/chemistry , Hydrogen-Ion Concentration , Ligands , Methanol/chemistry , Models, Chemical , Reproducibility of Results , Temperature , Time FactorsABSTRACT
A simple and specific high-performance liquid chromatographic (HPLC) method was developed for the pharmacokinetic study of vitexin-2''-O-rhamnoside (VOR) in rat after intravenous administration. The plasma samples were deproteinized with methanol after addition of internal standard (i.s.) hesperidin. HPLC analysis was performed on a Diamonsil ODS C18 analytical column, using acetonitrile-0.3% formic acid (20:80, v/v) as the mobile phase with UV detection at 270 nm. The standard curve was linear over the range of 0.1070-21.41 microg/mL in rat plasma. The average extraction recovery of VOR was 97.9+/-3.1%, and the relative standard deviations (R.S.D.s) of the intra- and inter-day precisions were no more than 7.4 and 8.5%, respectively. The lower limit of quantification (LLOQ) was 0.1070 microg/mL. The AUC of VOR was proportional to the dose after intravenous administration of 15, 30, 60 and 120 mg/kg body weight, and the elimination half-life (t1/2beta), systemic clearance (Cl) and apparent volume of distribution (Vc) were not significantly different among the four doses, and all the results indicated that the pharmacokinetics of VOR in rat obeyed first-order kinetics.
