Supplementary Table IV.
Intraday and interday precision and accuracy of HPLC methods used for determination of statins in human plasma samples. Both intraday and interday assay variability values were within acceptance criteria for all tested compounds at the 4 QC levels
| Statins | Quality control levels |
Intraday (n = 6) |
Interday (n = 6) |
|||
|---|---|---|---|---|---|---|
| Concentration (μmol/L) | Concentration (μg/mL) | Precision (RSD%)∗ | Accuracy (RE%)† | Precision (RSD%) | Accuracy (RE%) | |
| Simvastatin lactone | LLOQ (0.156) | 0.065 | 9.70 | −5.94 | 14.56 | −3.05 |
| LQC (5) | 2.09 | 3.74 | −10.13 | 14.79 | −3.12 | |
| MQC (60) | 25.12 | 12.43 | 0.57 | 14.30 | 0.50 | |
| HQC (120) | 50.23 | 9.78 | −1.36 | 14.44 | 5.90 | |
| Simvastatin hydroxy acid | LLOQ (0.313) | 0.142 | 11.61 | 9.98 | 11.58 | 17.42 |
| LQC (5) | 2.26 | 14.83 | 0.37 | 10.91 | −1.33 | |
| MQC (60) | 27.21 | 6.54 | −6.14 | 6.43 | −2.45 | |
| HQC (120) | 54.43 | 6.72 | −11.70 | 7.69 | −8.93 | |
| Pravastatin lactone | LLOQ (0.234) | 0.095 | 3.33 | 13.88 | 6.95 | 14.65 |
| LQC (10) | 4.06 | 2.38 | −3.17 | 6.99 | −9.67 | |
| MQC (100) | 40.65 | 12.46 | 2.34 | 11.74 | 5.21 | |
| HQC (200) | 81.30 | 4.43 | 6.91 | 7.27 | 8.16 | |
| Pravastatin hydroxy acid | LLOQ (0.469) | 0.209 | 17.39 | −9.86 | 16.02 | −4.53 |
| LQC (10) | 4.46 | 8.35 | 12.51 | 8.17 | 11.50 | |
| MQC (100) | 44.65 | 11.84 | −10.22 | 13.45 | −10.71 | |
| HQC (200) | 89.30 | 9.85 | −12.94 | 10.46 | −11.32 | |
Abbreviations:HQC, high concentration quality control; LLOQ, lower limit of quantification; LQC, low concentration quality control; MQC, medium concentration quality control.
∗
Relative standard deviation (RSD%) = (standard deviation [SD]/mean of obtained concentration) × 100.
†
Relative error (RE%) = ([measured concentration−nominal concentration]/nominal concentration) × 100.