title: Stability of generic brands of meropenem reconstituted in isotonic saline.
abstract: BACKGROUND
  Meropenem is a relatively unstable compound when dissolved. Currently, all available data have been derived from tests on the original product from Astrazeneca, and it is unsure if these data can be extrapolated to the stability of other commercially available vials. The aim of this study was therefore to assess the stability of four different brands of meropenem to be used as a prolonged or continuous infusion.
  
  
  METHODS
  Commercially available meropenem vials were reconstituted and mixed with 0.9% sodium chloride to produce solutions with concentrations of 10.20 and 40 mg/mL in polypropylene syringes, which were kept at 25 °C. Samples were taken immediately after preparation and up to 12 hours. Solutions retaining >90% of the initial concentration were considered stable.
  
  
  RESULTS
  The stability was concentration-dependent. At 25 °C, all 10 and 20 mg/mL solutions were stable for 12 hours in 0.9% sodium chloride, while the 40 mg/mL solutions were stable for a maximum of 8 hours. Stability of the different vials of meropenem was comparable for the time period tested (related samples Friedman's two way of analysis of variance by ranks, P=0.282).
  
  
  CONCLUSIONS
  All tested commercially available vials of meropenem in a concentration of 10 and 20 mg/mL were stable for 12 hours at 25 °C when diluted in 0.9% sodium chloride. The 40 mg/mL solutions were stable for a maximum of 8 hours. This report is the first to show equivalent stability between different commercially available vials of meropenem.
authors.affiliation: Department of Clinical Chemistry, Microbiology and Immunology, Ghent University, Ghent, Belgium - mieke.carlier@ugent.be.
authors.forename: M
authors.initials: M
authors.lastname: Carlier
authors.forename: V
authors.initials: V
authors.lastname: Stove
authors.forename: A G
authors.initials: AG
authors.lastname: Verstraete
authors.forename: J J
authors.initials: JJ
authors.lastname: De Waele
mesh_terms: D000900:Anti-Bacterial Agents / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid; D004339:Drug Compounding; D004355:Drug Stability; D004356:Drug Storage; D007552:Isotonic Solutions; D000077731:Meropenem; D012965:Sodium Chloride; D013594:Syringes; D013845:Thienamycins / Q000032:analysis*
chemical_list: D000900:Anti-Bacterial Agents; D007552:Isotonic Solutions; D013845:Thienamycins; D012965:Sodium Chloride; D000077731:Meropenem