Table 5.

Application of standard addition technique using the proposed methods

Method	Pharmaceutical (µg/mL)	Remdesivir		MFX
		Pure added (µg/mL)	% R *	Pure added (µg/mL)	% R *
Ratio derivative	RDV 1 (1.01)* MFX 4 (3.93)*	1	98.18	3	99.34
		2	99.03	4	101.27
		3	98.01	5	100.07
	Mean		98.41		100.23
	%RSD		0.552		0.973
Ratio difference	RDV 1 (1.01)* MFX 4 (4.07)*	1	100.92	3	99.05
		2	99.98	4	100.57
		3	100.65	5	98.48
	Mean		100.52		99.36
	%RSD		0.486		1.086
Mean centering	RDV 1 (0.99)* MFX 4 (3.97)*	1	98.40	3	101.94
		2	100.23	4	99.06
		3	98.21	5	100.35
	Mean		98.95		100.45
	%RSD		1.129		1.436
Area under curve method	RDV 1 (1.02)* MFX 4 (3.92)*	1	100.88	3	99.79
		2	98.36	4	99.93
		3	100.56	5	98.06
	Mean		99.94		99.26
	%RSD		1.373		1.052
Q-analysis method	RDV 1 (0.99)* MFX 4 (3.97)*	1	100.31	3	101.80
		2	100.11	4	100.74
		3	98.86	5	101.51
	Mean		99.76		101.35
	%RSD		0.788		0.540
Bivariate method	RDV 1 (0.99)* MFX 4 (3.93)*	1	101.65	3	98.33
		2	98.95	4	101.75
		3	98.81	5	98.52
	Mean		98.80		99.53
	%RSD		1.602		1.927

^* Average of three determinations