title: The evaluation of rifampicin bioavailabilities of fixed-dose combinations of anti-tuberculosis drugs: procedures for ensuring laboratory proficiency.
abstract: METHODS
  The perceived need to demonstrate whether or not the rifampicin bioavailability of commercially manufactured fixed-dose combinations is satisfactory.
  
  
  OBJECTIVE
  To establish an international laboratory network to assess rifampicin bioavailability.
  
  
  METHODS
  Convenient assay kits were devised to evaluate the ability of laboratories in China, India, Italy, South Africa, Thailand and the USA to determine plasma and urinary concentrations of rifampicin and desacetyl-rifampicin.
  
  
  RESULTS
  Five laboratories, all of whom used high pressure liquid chromatographic methods, were shown to be able to accurately and precisely determine the two compounds.
  
  
  CONCLUSIONS
  Such a procedure is simple, convenient and objective and could be further employed to enlarge the intended international laboratory network.
authors.affiliation: Department of Medical Microbiology, St. George's Hospital Medical School, London, UK.
authors.forename: G A
authors.initials: GA
authors.lastname: Ellard
mesh_terms: D000904:Antibiotics, Antitubercular / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics* / Q000652:urine; D000995:Antitubercular Agents / Q000008:administration & dosage*; D001682:Biological Availability; D004338:Drug Combinations; D006801:Humans; D007753:Laboratories / Q000592:standards*; D016730:Program Development; D011786:Quality Control; D012293:Rifampin / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics* / Q000652:urine; D014376:Tuberculosis / Q000188:drug therapy; D014944:World Health Organization
chemical_list: D000904:Antibiotics, Antitubercular; D000995:Antitubercular Agents; D004338:Drug Combinations; D012293:Rifampin