title: A case study of validation and sample analysis for the determination of zotarolimus in various tissues.
abstract: BACKGROUND
  Biodistribution of drug and drug candidates offers critical information regarding drug disposition in target and nontarget tissues. Concentrations of therapeutic agents in target tissue provide the foundation for efficacy, while concentrations in nontarget tissue pose potential safety risks. Analysis of tissue samples can sometimes provide important information during the development of a drug candidate, especially at early stages when radio labeled drug material is not readily available.
  
  
  RESULTS
  Determining the appropriate approach to allow for accurate, precise and reproducible drug concentration measurements from tissue samples requires addressing issues not present in routinely analyzed biological matrices, that is, plasma. We present here the issues encountered and techniques applied during the development, validation and application of a method for the determination of zotarolimus in a variety of tissues.
  
  
  CONCLUSIONS
  When well controlled, analysis of tissue samples can be performed in a manner similar to liquid biological matrices.
authors.affiliation: AbbVie, North Chicago, IL 60064, USA. michael.reimer@abbvie.com
authors.forename: M Todd
authors.initials: MT
authors.lastname: Reimer
authors.forename: Xia
authors.initials: X
authors.lastname: Wan
authors.forename: Jun
authors.initials: J
authors.lastname: Zhang
mesh_terms: D000818:Animals; D002853:Chromatography, Liquid / Q000379:methods*; D007166:Immunosuppressive Agents / Q000032:analysis* / Q000493:pharmacokinetics; D020123:Sirolimus / Q000031:analogs & derivatives* / Q000032:analysis / Q000097:blood / Q000493:pharmacokinetics; D013552:Swine; D053719:Tandem Mass Spectrometry / Q000379:methods*; D054928:Validation Studies as Topic
chemical_list: D007166:Immunosuppressive Agents; C489443:zotarolimus; D020123:Sirolimus