Use of Alizarin Red S as an Ion-Pair Reagent for the Spectrophotometric Assay of Fexofenadine in Pharmaceuticals and in Spiked Human Urine

Table 4

Evaluation of intraday and interday precision and accuracy.

Method	FFH taken; (μg mL^−1)	Intraday (𝑛=5)			Interday (𝑛=5)
		FFH found^a (μg mL^−1)	%RSD^b	%RE^c	FFH; found^a   (μg mL^−1)	%RSD^b	%RE^c
A	4.00	4.08	1.26	2.11	4.10	1.06	2.65
	6.00	6.14	1.32	2.34	6.17	0.62	2.85
	8.00	8.15	1.91	1.77	8.18	0.59	2.34
B	1.00	1.01	1.52	1.20	1.02	2.00	2.04
	2.00	1.98	1.88	0.86	1.97	1.74	1.27
	3.00	2.95	0.87	1.62	2.93	0.91	2.05

^aMean value of five determinations; ^brelative standard deviation (%); ^crelative error (%).