title: Active ingredient consistency of commercially available glucosamine sulfate products.
abstract: OBJECTIVE
  To assess the content of active ingredient in over-the-counter (OTC) glucosamine sulfate (GLS) preparations.
  
  
  METHODS
  We analyzed in a coded, blind manner 14 commercially available capsules or tablets of GLS, plus one herbal mixture as a control. We used a high performance liquid chromatography system as described.
  
  
  RESULTS
  The amount of free base varied from 41 to 108% of the mg content stated on the label; the amount of glucosamine varied from 59 to 138% even when expressed as sulfate.
  
  
  CONCLUSIONS
  If GLS is used as a therapeutic agent, it is important that the products conform to a standard in their description. The content is probably best expressed in terms of free base.
authors.affiliation: Faculties of Pharmacy and Medicine, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Anthony S
authors.initials: AS
authors.lastname: Russell
authors.forename: Ali
authors.initials: A
authors.lastname: Aghazadeh-Habashi
authors.forename: Fakhreddin
authors.initials: F
authors.lastname: Jamali
mesh_terms: D003132:Commerce; D004348:Drug Labeling / Q000592:standards*; D005944:Glucosamine / Q000032:analysis* / Q000592:standards*; D006801:Humans; D004366:Nonprescription Drugs / Q000592:standards*; D012492:Salts / Q000032:analysis
chemical_list: D004366:Nonprescription Drugs; D012492:Salts; D005944:Glucosamine