title: Ultrasensitive sub-pg/ml determination of tiotropium bromide in human plasma by 2D-UHPLC-MS/MS: challenges and solutions.
abstract: BACKGROUND
  To adequately support pharmacokinetic evaluations of tiotropium bromide in planned clinical studies. It was desirable to measure it with a LLOQ of sub pg/ml.
  
  
  RESULTS
  A sensitive bioanalytical method for the determination of tiotropium in human plasma sample was successfully developed and validated in the range of 0.2-100 pg/ml. The method was successfully applied to support two clinical studies of over 3000 samples. The overall incurred sample reanalysis passing rate was 93.7%.
  
  
  CONCLUSIONS
  The combination of a dual stage liquid-liquid extraction and a 2D ultra-HPLC greatly reduced matrix effects and increased assay sensitivity. When developing effective ultrasensitive assays, it is imperative to balance the aspects related to sensitivity with those that will ensure assay ruggedness.
authors.affiliation: PPD® Laboratories, 3230 Deming Way, Middleton, WI 53562, USA.
authors.forename: Jingduan
authors.initials: J
authors.lastname: Chi
authors.affiliation: PPD® Laboratories, 3230 Deming Way, Middleton, WI 53562, USA.
authors.forename: Fumin
authors.initials: F
authors.lastname: Li
authors.affiliation: PPD® Laboratories, 2240 Dabney Rd, Richmond, VA 23230, USA.
authors.forename: Rand
authors.initials: R
authors.lastname: Jenkins
mesh_terms: D001993:Bronchodilator Agents / Q000097:blood*; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D006801:Humans; D057230:Limit of Detection; D059625:Liquid-Liquid Extraction / Q000379:methods; D015203:Reproducibility of Results; D053719:Tandem Mass Spectrometry / Q000379:methods*; D000069447:Tiotropium Bromide / Q000097:blood*
chemical_list: D001993:Bronchodilator Agents; D000069447:Tiotropium Bromide
keywords: 2D-UHPLC; dual-stage liquid–liquid extraction; inhaled therapy; tiotropium bromide; ultrasensitive bioanalysis (sub pg/ml)