title: Stability of methacholine chloride in isotonic sodium chloride using a capillary electrophoresis assay.
abstract: OBJECTIVE
  To investigate the stability of methacholine chloride in 0.9% sodium chloride solutions.
  
  
  METHODS
  Methacholine powder was mixed with diluent to a final concentration of 5 and 10 mg/ml. Duplicates of each admixture were divided and stored in glass vials at 25 degrees C, 4 degrees C and -20 degrees C for 12 months. At appropriate times intervals, samples were removed from solutions and analysed. Methacholine concentrations were measured using a high performance capillary electrophoresis assay.
  
  
  RESULTS
  No colour or other visual changes were seen in any sample. However, an additional peak was observed in some samples.
  
  
  CONCLUSIONS
  Methacholine chloride solutions 5 mg/ml were stable in isotonic sodium chloride after refrigeration or freezing over a period of one year; methacholine chloride solutions 10 mg/ml were stable for one year after freezing. The solutions stored at ambient temperature were stable for 35 days and for less than 14 days, respectively, for the 5 and the 10 mg/ml solutions.
authors.affiliation: Centre Hospitalier Universitaire de Brabois Adultes, Service Pharmacie, Nancy, France.
authors.forename: S
authors.initials: S
authors.lastname: Henn
authors.forename: P
authors.initials: P
authors.lastname: Monfort
authors.forename: J H
authors.initials: JH
authors.lastname: Vigneron
authors.forename: M A
authors.initials: MA
authors.lastname: Hoffman
authors.forename: M
authors.initials: M
authors.lastname: Hoffman
mesh_terms: D016085:Bronchoconstrictor Agents / Q000737:chemistry*; D003080:Cold Temperature; D004355:Drug Stability; D004356:Drug Storage; D019075:Electrophoresis, Capillary / Q000379:methods; D005615:Freezing; D007552:Isotonic Solutions; D016210:Methacholine Chloride / Q000737:chemistry*; D015203:Reproducibility of Results; D012965:Sodium Chloride / Q000737:chemistry*; D013997:Time Factors
chemical_list: D016085:Bronchoconstrictor Agents; D007552:Isotonic Solutions; D016210:Methacholine Chloride; D012965:Sodium Chloride