title: Analysis of the composition of 'original' and generic sevoflurane in routine use.
abstract: BACKGROUND
  Original sevoflurane (Sevofrane) contains a small amount of water, which can inhibit the production of hydrofluoric acid. Hydrofluoric acid is highly pungent, and sevoflurane that contains a high concentration of hydrofluoric acid is not suitable for volatile induction of anaesthesia. Recently, generic sevoflurane (Sevoness) has become available in some countries. The generic product is produced by a different method and kept in a different kind of bottle. We questioned whether the original and generic sevoflurane differed in their composition and thus might differ in their resistance to degradation.
  
  
  METHODS
  Sevoflurane from groups of three bottles of Sevofrane and three bottles of Sevoness was kept in the bottle at 24-37 degrees C for 2 weeks or in two kinds of vaporizer for 3 days, and the resulting contents measured by gas chromatography.
  
  
  RESULTS
  Both products contained sevoflurane concentrations exceeding 99.998%. Fluoride ion concentration did not differ between the products (0.043 ppm). The original sevoflurane contained more (0.07% w/v) water than the generic anaesthetic (0.003% w/v). Original sevoflurane contained 5 ppm compound A, 10 ppm sevomethylether, and 5 ppm of unknown materials. Generic sevoflurane contained 32 ppm hexafluoroisopropanol and 12 ppm of unknown materials. While stored in a vaporizer for 3 days, the water content in the original sevoflurane decreased by two-thirds but the water in the generic sevoflurane increased by a factor of three-fold.
  
  
  CONCLUSIONS
  Generic sevoflurane contains high-quality sevoflurane and only a small amount of fluoride ions, making it comparable with the original sevoflurane product.
authors.affiliation: Department of Anesthesiology, Sapporo Medical University School of Medicine, South 1, West 16, Chuo-ku, Sapporo, Hokkaido 060-8543, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Yamakage
authors.forename: N
authors.initials: N
authors.lastname: Hirata
authors.forename: H
authors.initials: H
authors.lastname: Saijo
authors.forename: J-I
authors.initials: JI
authors.lastname: Satoh
authors.forename: A
authors.initials: A
authors.lastname: Namiki
mesh_terms: D018685:Anesthetics, Inhalation / Q000737:chemistry*; D004355:Drug Stability; D004356:Drug Storage / Q000379:methods; D016568:Drugs, Generic / Q000737:chemistry*; D005459:Fluorides / Q000032:analysis; D006801:Humans; D008738:Methyl Ethers / Q000737:chemistry*; D009330:Nebulizers and Vaporizers; D000077149:Sevoflurane; D013696:Temperature; D014867:Water / Q000032:analysis
chemical_list: D018685:Anesthetics, Inhalation; D016568:Drugs, Generic; D008738:Methyl Ethers; D014867:Water; D000077149:Sevoflurane; D005459:Fluorides