Development and Validation of a Simple, Green Infrared Spectroscopic Method for Quantitation of Sildenafil Citrate in Siloflam Tablets of Unknown Manufacturing Formula
Table 3
Results of repeatability and intermediate precision.
Number of sample solutions
Sample weight (mg)
Paracetamol weight (mg, purity: 99.7%)
Calculated R value (%)
Mass content of sildenafil in tablet (%, m/m)
Day 1, analyst 1
1
268.15
99.28
51.02
38.4
2
268.38
99.25
50.97
38.3
3
266.25
99.06
50.93
38.5
4
268.92
99.33
51.02
38.4
5
263.55
100.29
49.72
37.5
6
267.32
99.74
50.38
37.8
Average (1–6)
38.2
RSD (%) (1–6)
1.1
Day 2, analyst 2
7
268.12
100.56
50.26
37.8
8
266.32
100.32
50.30
38.0
9
269.15
100.38
50.36
37.7
10
268.06
100.66
50.69
38.5
11
264.35
101.43
49.37
37.3
12
265.43
100.27
50.90
39.0
Average (1–12)
38.1
RSD (%) (1–12)
1.6
Results obtained on day 1 by analyst 1 (sample numbers 1–6) were used for evaluating repeatability and those obtained on day 1 and day 2 (sample numbers 1–12) were used together for evaluating intermediate precision.
