title: Stability and compatibility of reconstituted ertapenem with commonly used i.v. infusion and coinfusion solutions.
abstract: OBJECTIVE
  The stability of ertapenem sodium in various commonly used i.v. infusion solutions and its compatibility with coinfusion solutions was studied.
  
  
  METHODS
  Ertapenem was reconstituted with sterile water for injection and then diluted with various commercial i.v. infusion solutions to concentrations of 10 and 20 mg/mL. The solutions were stored in flexible polyvinyl chloride containers at 4 and 25 degrees C and in sterile glass vials at -20 degrees C. The drug's stability at 4 degrees C was monitored daily for up to 10 days, at 25 degrees C at appropriate hourly intervals for up to 30 hours, and at -20 degrees C. The daily for up to 14 days. Compatibility with the coinfusion solutions was monitored for up to eight hours at room temperature. Stability assays were conducted until the ertapenem concentration decreased by 10% or the corresponding degradation products exceeded the approved specifications. Ertapenem concentrations were determined by a stability-indicating high-performance liquid chromatography assay.
  
  
  RESULTS
  Ertapenem was more stable in solutions stored at 4 degrees C versus 25 degrees C. Samples frozen at -20 degrees C showed extreme variability. Ertapenem 10 mg/mL was stable for a longer time than at the 20-mg/mL concentration. Ertapenem demonstrated the greatest stability in 0.9% and 0.225% sodium chloride solutions.
  
  
  CONCLUSIONS
  Ertapenem sodium injection 10 and 20 mg/mL are relatively stable in sodium chloride injections and Ringer's solution when stored at 25 and 4 degrees C, but are unstable in mannitol and dextrose solutions. The drug can be coinfused with hetastarch, heparin sodium, and potassium chloride over several hours.
authors.affiliation: Merck & Co., Inc., WP 78-210, P.O. Box 4, West Point, PA 19486, USA. michael_mcquade@merck.com
authors.forename: Michael S
authors.initials: MS
authors.lastname: McQuade
authors.forename: Vincent
authors.initials: V
authors.lastname: Van Nostrand
authors.forename: Joseph
authors.initials: J
authors.lastname: Schariter
authors.forename: Jennifer Domsicz
authors.initials: JD
authors.lastname: Kanike
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Forsyth
mesh_terms: D002851:Chromatography, High Pressure Liquid; D004347:Drug Interactions; D004355:Drug Stability; D000077727:Ertapenem; D006302:Health Services Research; D007262:Infusions, Intravenous; D007769:Lactams / Q000008:administration & dosage / Q000737:chemistry; D014481:United States; D047090:beta-Lactams
chemical_list: D007769:Lactams; D047090:beta-Lactams; D000077727:Ertapenem