Growth of bacteria in prefilled syringes stored in home refrigerators

Insulin was examined for the rate of bacterial growth after being stored in prefilled syringes in home refrigerators and in a controlled laboratory refrigerator. Home refrigerators were used to simulate conditions that exist in client homes to establish the safety of storing insulin in prefilled syringes in uncontrolled environments. Insulin from each source was inoculated on three different media and incubated at three temperatures in three oxygen environments. A total of 768 cultures were examined. It was found that temperature had a significant effect on the incidence of bacteria. The difference in incident of bacteria between syringes stored in the controlled versus uncontrolled environments was not statistically significant.