title: Activity of dissolved mitomycin C after different methods of long-term storage.
abstract: OBJECTIVE
  The cytostatic substance mitomycin C (MMC) is used in trabeculectomy to enhance the success rate in problematic cases and is usually dissolved immediately before application, but only approximately 1% of the substance is needed for treatment. The authors evaluated different methods of long-time storage of MMC for a period of 6 months.
  
  
  METHODS
  MMC in concentrations of 0.02, 0.05, 0.1, 0.2, and 0.4 mg/mL was prepared at the local pharmaceutical department and stored at +22 degrees C (room temperature), +4 degrees C (refrigerator), -20 degrees C (freezer compartment), and -196 degrees C (liquid N2). The activity of MMC was evaluated with a microagar diffusion method (bioassay) after 30 minutes, and 1, 3, 7, 14, 30, 90, and 180 days for the different concentrations and storage methods.
  
  
  RESULTS
  There was no difference in the long-term stability of the investigated MMC concentrations. Ninety percent of the initial activity was preserved after storage at +22 degrees C for 1 week, -20 degrees C for 1 month, or +4 degrees C for 3 months. At 6 months the activities were 16%, 48%, and 78% of the initial values, respectively. The activity of MMC stored at -196 degrees C is not reduced after storage for 6 months.
  
  
  CONCLUSIONS
  Dissolved MMC can be stored in the refrigerator for up to 3 months without significant loss of activity. Storage at room temperature is not recommended. Costs of trabeculectomy can be reduced by storage of reconstituted solutions rather than dissolving MMC before each glaucoma surgery.
authors.affiliation: Department of Ophthalmology, Medical School, University of Vienna, Vienna, Austria.
authors.forename: M
authors.initials: M
authors.lastname: Georgopoulos
authors.forename: C
authors.initials: C
authors.lastname: Vass
authors.forename: Z
authors.initials: Z
authors.lastname: Vatanparast
authors.forename: A
authors.initials: A
authors.lastname: Wolfsberger
authors.forename: A
authors.initials: A
authors.lastname: Georgopoulos
mesh_terms: D000903:Antibiotics, Antineoplastic / Q000737:chemistry / Q000494:pharmacology; D003080:Cold Temperature; D004355:Drug Stability; D004356:Drug Storage / Q000379:methods*; D005901:Glaucoma / Q000601:surgery; D008826:Microbial Sensitivity Tests; D016685:Mitomycin / Q000737:chemistry / Q000494:pharmacology*; D009883:Ophthalmic Solutions; D004364:Pharmaceutical Preparations; D013211:Staphylococcus aureus; D013997:Time Factors; D014130:Trabeculectomy
chemical_list: D000903:Antibiotics, Antineoplastic; D009883:Ophthalmic Solutions; D004364:Pharmaceutical Preparations; D016685:Mitomycin