Determination of Isosorbide-5-Mononitrate in Human Plasma by High-Performance Liquid Chromatography-Tandem Mass Spectrometry and Its Application to a Bioequivalence Study
Table 4
Stability assessments of 5-ISMN in plasma (n = 6).
Matrix
Storage conditions
Nominal con. (ng/mL)
Measured con. (mean ± SD, ng/mL)
Precision (RSD %)
Accuracy (%)a
Blood
Room temperature for 2 h
8
7.76 ± 0.18
2.3
−2.5
200
212 ± 5.18
2.4
6.0
Plasma
Three circles of freeze/thaw
8
8.60 ± 0.35
4.1
7.5
800
833.2 ± 8.82
1.1
4.1
In autosampler for 72 h after extraction
8
8.62 ± 0.43
5.1
7.8
800
823.2 ± 24.53
3.0
2.9
Room temperature for 8 h
8
7.90 ± 0.35
4.5
−1.3
800
823.5 ± 7.23
0.9
2.9
Long-term stability (−30°C for 63 days)
8
7.49 ± 0.53
7.1
−6.4
800
820.5 ± 26.85
3.3
2.6
Long-term stability (−80°C for 91 days)
8
8.31 ± 0.19
2.2
4.0
800
755.67 ± 9.93
1.3
−5.5
Repeat injection for 64 h after extraction
8
7.71 ± 0.22
2.9
−3.6
800
821.7 ± 25.12
3.1
2.7
Concentration is in 3 significant figures; SD, standard deviation; RSD%, percent relative standard deviation (in one decimal place). aExpressed as ((mean measured concentration−nominal concentration)/(nominal concentration)) × 100 (in one decimal place).
