Stability of imipenem and cilastatin sodium in total parenteral nutrient solution

JPEN J Parenter Enteral Nutr. 1990 May-Jun;14(3):306-9. doi: 10.1177/0148607190014003306.


The chemical stability and compatibility of imipenem-cilastatin sodium (Primaxin) in two different total parenteral nutrient (TPN) solutions was determined. TPN solutions consisted of 4.25% and 5% amino acids with 25% and 35% dextrose, respectively. Imipenem-cilastatin sodium was constituted with 10 ml of sterile water and admixed with 90 ml of TPN solution for a final concentration of 5 mg/ml of each drug. The final solutions were assayed at times 0 (immediately after admixture), 15 min, 30 min, 1, 4, 8, and 24 hr by a stability-indicating high-performance liquid chromatographic assay. Concurrently, test TPN solutions were monitored for pH changes, color changes, and precipitate formation. The potential effect of imipenem-cilastatin sodium on the stability of amino acids and other TPN additives was not evaluated. Imipenem and cilastatin sodium was stable (greater than or equal to 90% recovered) in each TPN solution at 15 min. A significant (greater than or equal to 10%) and steady decrease of imipenem recovery occurred at subsequent sampling times. Cilastatin appeared more stable than imipenem in both TPN solutions. A physical color change from colorless to dark orange appeared in each TPN solution over the 24-hr study period. Imipenem-cilastatin sodium is stable for 15 min in the TPN solutions studied; however, until the stability of the amino acids can be determined, the antibiotic should be administered through a separate line or Y-site while the TPN infusion is interrupted.

MeSH terms

  • Anti-Bacterial Agents / administration & dosage
  • Anti-Bacterial Agents / analysis
  • Anti-Bacterial Agents / standards*
  • Chromatography, High Pressure Liquid
  • Cilastatin / administration & dosage
  • Cilastatin / analysis
  • Cilastatin / standards*
  • Cilastatin, Imipenem Drug Combination
  • Drug Combinations / administration & dosage
  • Drug Combinations / analysis
  • Drug Combinations / standards
  • Drug Incompatibility
  • Drug Stability
  • Food, Formulated* / analysis
  • Humans
  • Imipenem / administration & dosage
  • Imipenem / analysis
  • Imipenem / standards*
  • Parenteral Nutrition, Total*


  • Anti-Bacterial Agents
  • Drug Combinations
  • Cilastatin
  • Imipenem
  • Cilastatin, Imipenem Drug Combination