Development and Validation of a Simple, Green Infrared Spectroscopic Method for Quantitation of Sildenafil Citrate in Siloflam Tablets of Unknown Manufacturing Formula

Table 1

Working standard mixtures for calibration model.

Number	Quantity of Siloflam tablet powder (containing 37.94% (m/m) sildenafil citrate) (mg)	Quantity of paracetamol (purity: 99.7%) (mg)	R value (%)
1	156.93	140.97	29.79
2	159.41	141.28	30.08
3	209.88	120.36	39.93
4	206.32	119.26	39.74
5	260.25	101.43	49.45
6	257.91	100.28	49.51
7	309.85	80.65	59.43
8	308.75	80.53	59.38
9	361.28	61.46	69.15
10	360.36	61.23	69.17