Stability-Indicating Gradient RP-LC Method for the Determination of Process and Degradation Impurities in Bosentan Monohydrate: An Endothelin Receptor Antagonist
Table 3
Validation data results of related substances of bosentan monohydrate.
Related substances results
Compound
IMP-A
IMP-B
IMP-C
IMP-D
IMP-E
Bosentan monohydrate
Precision; Mean (%RSD)
Method Precision ()
0.174 (0.57)
0.082 (1.22)
0.169 (1.18)
0.152 (0.66)
0.151 (0.66)
—
Intermediate precision ()
0.170 (0.59)
0.072 (1.39)
0.169 (0.59)
0.154 (1.30)
0.152 (0.66)
—
Overall results ()
0.172 (1.16)
0.077 (6.49)
0.169 (0.59)
0.153 (1.31)
0.151 (0.66)
—
Limit of detection (LOD)
LOD (μg mL−1 )
0.044
0.036
0.025
0.068
0.027
0.053
LOD (% w.r.t. test)
0.004
0.004
0.003
0.007
0.003
0.005
Limit of quantitations (LOQ)
LOQ (μg mL−1 )
0.135
0.109
0.077
0.206
0.081
0.160
LOQ (% w.r.t. test)
0.014
0.011
0.008
0.021
0.008
0.016
Linearity: for related substances LOQ to 250% of specification level
Correlation coefficient ()
0.99953
0.99996
0.99975
0.99984
0.99997
0.99998
Slope
28308.09
37412.93
30031.08
24896.49
31706.44
34898.75
Intercept
−1161.25
69.93
−167.92
195.10
172.24
2294.25
Accuracy: mean recovery (%RSD): LOQ to 150% of specification level
LOQ
93.33 (7.14)
96.67 (5.97)
92.59 (6.93)
106.06 (2.47)
92.59 (6.93)
—
50%
107.92 (1.18)
90.99 (1.71)
98.64 (0.01)
102.22 (3.28)
98.68 (0.00)
—
100%
104.41 (0.74)
93.47 (0.83)
99.55 (1.72)
100.44 (1.01)
100.00 (0.66)
—
150%
102.49 (0.66)
91.62 (1.01)
99.25 (0.95)
99.41 (0.26)
98.54 (0.25)
—
% w.r.t. test LOD LOQ values are in % with respect to test concentration of 1000 μg mL−1.
