title: Chondroitin product selection for the glucosamine/chondroitin arthritis intervention trial.
abstract: OBJECTIVE
  To select a high-quality chondroitin dosage form and/or an appropriate source of sodium chondroitin for the National Institutes of Health's Glucosamine/Chondroitin Arthritis Intervention Trial (GAIT).
  
  
  METHODS
  Controlled experimental trials.
  
  
  METHODS
  Laboratory.
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  Commercially available chondroitin products were reviewed, and purified sodium chondroitin from two suppliers was evaluated through tests (infrared and near-infrared identification, moisture content, pH, optical rotation, color and clarity of aqueous solutions prepared from the powders, protein contamination, total residue following ignition and nitrogen content, determination of sodium chondroitin molecular weight, disaccharide analysis, and measurement of chondroitin, sodium, and total glycosaminoglycan content) and an onsite supplier audit.
  
  
  METHODS
  Purity, potency, and quality of sodium chondroitin powders.
  
  
  RESULTS
  No commercially available chondroitin product was deemed appropriate for use in GAIT. Samples of sodium chondroitin powder from two suppliers exhibited similar disaccharide and glycosaminoglycan content. Each contained approximately 2% hyaluronic acid and 8%-9% unsulfated disaccharide. Potency was inconsistent across groups, which might have resulted from different analytical methods and choice of reference standard. Mean potency obtained by five separate methods ranged from 82.2% to 95.5% for one supplier, 92.5% to 110.1% for another, and 95.1% to 112.5% for a commercially obtained reference standard. Critical issues raised by the results include choice of reference standard, selection of assay method, and the consistent appearance of an unidentifiable contaminant present in all three lots from one supplier.
  
  
  CONCLUSIONS
  This blinded study determined methods to identify acceptable agents and provided results, which, in addition to regulatory compliance supplier audits, formed the basis for chondroitin product selection in GAIT.
authors.affiliation: Biopharmaceutics/Pharmacokinetics Laboratory, VA Cooperative Studies Program, Clinical Research Pharmacy Coordinating Center, 2401 Centre Ave., SE, Albuquerque, NM 87106, USA. jamie.barnhill@csp.research.med.va.gov
authors.forename: Jamie G
authors.initials: JG
authors.lastname: Barnhill
authors.forename: Carol L
authors.initials: CL
authors.lastname: Fye
authors.forename: David W
authors.initials: DW
authors.lastname: Williams
authors.forename: Domenic J
authors.initials: DJ
authors.lastname: Reda
authors.forename: Crystal L
authors.initials: CL
authors.lastname: Harris
authors.forename: Daniel O
authors.initials: DO
authors.lastname: Clegg
mesh_terms: D002807:Chondroitin / Q000032:analysis* / Q000592:standards* / Q000627:therapeutic use; D017326:Clinical Trials, Phase III as Topic; D019587:Dietary Supplements; D004338:Drug Combinations; D005944:Glucosamine / Q000032:analysis* / Q000592:standards* / Q000627:therapeutic use; D049690:History, Ancient; D006801:Humans; D006813:Humidity; D006863:Hydrogen-Ion Concentration; D008970:Molecular Weight; D009904:Optical Rotation; D010003:Osteoarthritis / Q000188:drug therapy*; D012015:Reference Standards
chemical_list: D004338:Drug Combinations; D002807:Chondroitin; D005944:Glucosamine