TABLE 3.
Stability of ISZ in plasmaa
| Storage condition and sample concn (mg/liter) | Found concn (mean mg/liter ± SD) | Accuracyb (%) | Precisionc (% RSD) |
|---|---|---|---|
| 24 h at 20°C | |||
| LQC (0.3) | 0.300 ± 0.003 | 100.1 | 0.833 |
| HQC (20.0) | 19.603 ± 0.142 | 98.0 | 0.727 |
| 7 days at 20°C | |||
| LQC (0.3) | 0.292 ± 0.005 | 97.2 | 1.652 |
| HQC (20.0) | 19.373 ± 0.420 | 96.9 | 2.170 |
| Freeze (−20°C) for 48 h | |||
| LQC (0.3) | 0.312 ± 0.008 | 104.0 | 2.606 |
| HQC (20.0) | 20.265 ± 0.575 | 101.3 | 2.840 |
| Freeze (−20°C) for 60 days | |||
| LQC (0.3) | 0.319 ± 0.040 | 106.4 | 12.545 |
| HQC (20.0) | 22.119 ± 0.941 | 110.6 | 4.255 |
| Three freeze-thaw cycles | |||
| LQC (0.3) | 0.308 ± 0.014 | 102.7 | 4.611 |
| HQC (20.0) | 21.526 ± 0.500 | 107.6 | 2.321 |
| Sample + IS for 24 h at 20°C | |||
| LQC (0.3) | 0.298 ± 0.009 | 99.2 | 3.082 |
| HQC (20.0) | 21.654 ± 0.275 | 108.3 | 1.272 |
| In autosampler for 24 h at 20°C | |||
| LQC (0.3) | 0.291 ± 0.005 | 97.0 | 1.598 |
| HQC (20.0) | 19.172 ± 0.542 | 95.9 | 2.825 |
a
Intraday precision and accuracy values were determined for the LQC and HQC in filtered pooled human plasma samples after storage under various conditions. Five individually prepared samples were used for each concentration level and storage condition. IS, internal standard.
b
Accuracy is the percentage of the nominal value.
c
Precision is expressed as the percentage of the RSD of each calculated concentration.