title: Improved HPLC method for determination of four PPIs, omeprazole, pantoprazole, lansoprazole and rabeprazole in human plasma.
abstract: OBJECTIVE
  To develop a simple and rapid HPLC method for measuring of four proton-pump inhibitors (PPIs), omeprazole (OPZ), pantoprazole (PPZ), lansoprazole (LPZ) and rabeprazole (RPZ) concentrations in human plasma.
  
  
  METHODS
  Following a single step liquid-liquid extraction analytes along with an internal standard (IS) were separated using an isocratic mobile phase of phosphate buffer (10 mM)/acetonitrile (53/47, v/v adjusted pH to 7.3 with triethylamine) at flow rate of 1 mL/min on reverse phase TRACER EXCEL 120 ODS-A column at room temperature.
  
  
  RESULTS
  Total analytical run time for selected PPIs was 10 min. The assays exhibited good linearity (r(2)>0.99) over the studied range of 20 to 2500 ng/mL for OPZ, 20 to 4000 ng/mL for PPZ, 20 to 3000 ng/mL for LPZ and 20 to 1500 ng/mL for RPZ. The recovery of method was equal or greater than 80% and lower limit of quantification (LLOQ) was 20 ng/mL for four PPIs. Coefficient of variation and error at all of the intra-day and inter-day assessment were less than 9.2% for all compounds.
  
  
  CONCLUSIONS
  The results indicated that this method is a simple, rapid, precise and accurate assay for determination of four PPIs concentrations in human plasma. This validated method is sensitive and reproducible enough to be used in pharmacokinetic studies and also is time- and cost-benefit when selected PPIs are desired to be analyzed.
authors.affiliation: Department of Pharmacology, Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran.
authors.forename: Maryam
authors.initials: M
authors.lastname: Noubarani
authors.forename: Fariborz
authors.initials: F
authors.lastname: Keyhanfar
authors.forename: Manijeh
authors.initials: M
authors.lastname: Motevalian
authors.forename: Masoud
authors.initials: M
authors.lastname: Mahmoudian
mesh_terms: D053799:2-Pyridinylmethylsulfinylbenzimidazoles / Q000097:blood; D000328:Adult; D000897:Anti-Ulcer Agents / Q000097:blood*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006801:Humans; D064747:Lansoprazole; D008297:Male; D008875:Middle Aged; D009853:Omeprazole / Q000097:blood; D000077402:Pantoprazole; D054328:Proton Pump Inhibitors / Q000097:blood*; D064750:Rabeprazole; D015203:Reproducibility of Results; D055815:Young Adult
chemical_list: D053799:2-Pyridinylmethylsulfinylbenzimidazoles; D000897:Anti-Ulcer Agents; D054328:Proton Pump Inhibitors; D064747:Lansoprazole; D064750:Rabeprazole; D000077402:Pantoprazole; D009853:Omeprazole