BACKGROUND: A new simple, selective and accurate high-performance liquid chromatographic (HPLC) method utilising solid-phase extraction for the determination of pantoprazole in human plasma samples has been developed. AIM: The purpose of this paper was developing a new HPLC method suitable for the determination of pantoprazole in plasma samples, which enables simple and rapid isolation and concentration of the analysed drug.METHODS: The chromatographic separation was accomplished on a LiChroCart LiChrospher 60 RP select B column using a mobile phase composed of 0.2 % (V/V) water solution of triethylamine (pH 7) and acetonitrile (58:42, V/V) followed by UV detection was at 280 nm. The solid-phase extraction method using LiChrolut RP-18 (200 mg, 3 ml) was applied to the obtained good separation of investigated drug from endogenous plasma components. Best results were achieved when plasma samples were buffered with 0.1 mol/L KH2PO4 (pH 9) before extraction, eluted and reconstituted with acetonitrile and 0.001 mol/L NaOH after extraction, respectively. RESULTS: The standard calibration curves showed good linearity within the range of 25.0-4000.0 ng/mL with a correlation coefficient greater than 0.996. Retention times of pantoprazole and internal standard, lansoprazole was 4.1 and 6.0 min respectively. The limit of quantification was 25.0 ng/mL. For intra- and inter-day precision relative standard deviations ranged from 4.2 to 9.3%. The relative errors for stability investigations were ranged from 0.12 to -10.5%. CONCLUSION: This method has good precision and accuracy and was successfully applied to the pharmacokinetic and bioequivalence study of 40 mg pantoprazole in healthy volunteers.
Determination of Ranitidine in Human Plasma by SPE and ESI-LC-MS/MS for Use in Bioequivalence Studies
