title: Stability of colistimethate sodium in a disposable elastomeric infusion device.
abstract: Infections of the respiratory tract with Pseudomonas aeruginosa in cystic fibrosis patients are frequently treated with colistimethate sodium (CMS). For the intravenous administration of CMS a disposable elastomeric pump is a convenient option. To date, there are no data available on the chemical stability of CMS solutions stored in elastomeric pumps. We evaluated the chemical stability of 0.8 mg/mL solutions of CMS by measuring the degradation over a period of 7 days. Test samples were prepared by diluting CMS with saline solution (0.9%). The preparations were transferred to 100-mL elastomeric pumps and stored at 4 °C. The chemical stability was measured by a high-performance liquid chromatography method with UV detection. There was no degradation of CMS (<0.5% of CMS present as colistin) for at least 3 day at 4 °C, and after 7 days all test samples remained chemically stable (<5% of CMS present as colistin). Since colistin formed in pharmacy-compounded CMS solutions prior to administration may cause toxicity, we advise that the solution should be used before the hydrolysis of CMS occurs. Therefore, we recommend that the 0.8 mg/mL solution of CMS can be stored for up to 3 days at 4 °C in an elastomeric pump.
authors: Department of Hospital Pharmacy, Erasmus University Medical Center, Rotterdam, the Netherlands. Electronic address: a.abdulla@erasmusmc.nl.
authors: Alan
authors: A
authors: Abdulla
authors: Department of Hospital Pharmacy, Erasmus University Medical Center, Rotterdam, the Netherlands; Department of Medical Oncology, Erasmus MC Cancer Institute, Erasmus University Medical Center, Rotterdam, the Netherlands.
authors: Roelof W F
authors: RW
authors: van Leeuwen
authors: Department of Hospital Pharmacy, Erasmus University Medical Center, Rotterdam, the Netherlands.
authors: Aurelia H M
authors: AH
authors: de Vries Schultink
authors: Department of Hospital Pharmacy, Erasmus University Medical Center, Rotterdam, the Netherlands.
authors: Birgit C P
authors: BC
authors: Koch
mesh_terms: D003091:Colistin / Q000031:analogs & derivatives* / Q000737:chemistry; D004209:Disposable Equipment; D004355:Drug Stability; D007260:Infusion Pumps; D007262:Infusions, Intravenous
chemical_list: C004691:colistinmethanesulfonic acid; D003091:Colistin
keywords: Colistimethate sodium; Colistin; Elastomeric pump; Stability