Table 1.
Effect of temperature and duration of storage on whole blood hydroxyurea concentrations measured from dried blood collected using DMPK-C cards and VAMS devices at different concentrations.a
| Concentration, μg/mL | T = 7 days | T = 14 days | T = 30 days | |
|---|---|---|---|---|
| DMPK C cards | ||||
| Stored at 4 °C | 0.5 | 90.17 ± 0.44 | 81.75 ± 3.85 | 75.85 ± 4.08 |
| 60.0 | 65.37 ± 1.07 | 54.13 ± 3.39 | 48.58 ± 0.23 | |
| Stored at −20 °C | 0.5 | 95.08 ± 0.01 | 90.56 ± 13.29 | 96.07 ± 5.12 |
| 60.0 | 90.88 ± 1.83 | 92.99 ± 2.03 | 93.07 ± 3.11 | |
| Stored at −80 °C | 0.5 | 102.14 ± 0.59 | 97.41 ± 14.36 | 99.98 ± 3.81 |
| 60.0 | 93.69 ± 3.64 | 94.22 ± 2.34 | 100.45 ± 1.09 | |
| VAMS devices | ||||
| Stored at 4 °C | 0.5 | 87.90 ± 10.32 | 91.86 ± 7.97 | 75.11 ± 0.56 |
| 60.0 | 64.19 ± 1.28 | 51.98 ± 0.46 | 46.14 ± 0.98 | |
| Stored at −20 °C | 0.5 | 106.52 ± 12.11 | 103.15 ± 2.56 | 95.37 ± 6.01 |
| 60.0 | 83.69 ± 1.28 | 82.55 ± 1.65 | 82.48 ± 0.78 | |
| Stored at −80 °C | 0.5 | 101.92 ± 10.34 | 103.58 ± 3.20 | 106.00 ± 8.10 |
| 60.0 | 86.62 ± 1.86 | 90.21 ± 0.94 | 93.53 ± 0.68 |
a
The values are expressed as the % of the target concentration measured in freshly prepared samples of whole blood to which known concentrations of hydroxyurea were added.