Figure 4.

Time-related degradation of anomer-equilibrated streptozotocin solution. Streptozotocin was dissolved in citrate buffer, and solutions were stored at 4 °C in the dark for as long as 27 mo. Total streptozotocin concentration was determined by HPLC. The calculated rate of degradation was 0.1% daily. Insert, Streptozotocin solutions were kept at room temperature and sampled over 5 d. The calculated rate of degradation was 1% daily.