Infection control : IC
-
Infection control : IC · Dec 1985
Evaluation of the sterility and stability of insulin from multidose vials used for prolonged periods.
Diabetic patients frequently use their insulin vials for prolonged periods, even though antibacterial preservatives used in multidose insulin vials are not required to be effective beyond 28 days. For this reason, we evaluated the antibacterial activity present in multidose insulin vials for up to 50 days. Multidose lente insulin vials were inoculated with S. aureus and P. aeruginosa. ⋯ Insulin assays on 40 multidose insulin vials used for more than 28 days showed an average insulin content of 101.6 +/- 1.9 units/ml. This study did not demonstrate significant bacterial contamination, endotoxin activity, or insulin degradation of multidose insulin in vials used for periods longer than 28 days. In addition, antibacterial preservatives were more effective at room temperature than at refrigerator temperature; thus, the practice of patients not refrigerating insulin vials is sensible.