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

Table 7

Results of recovery study by standard addition method.

Tablets studied	Method A				Method B
	FFH in tablets, μg mL^−1	Pure FFH added, μg mL^−1	Total found, μg mL^−1	Pure FFH recovered*, Percent ± SD	FFH in tablets, μg mL^−1	Pure FFH added, μg mL^−1	Total found, μg mL^−1	Pure FFH recovered*, percent ± SD
Allegra-180	3.93	2.0	5.91	99.20±0.93	1.00	0.5	1.51	102.8±1.00
	3.93	4.0	7.87	98.56±0.57	1.00	1.0	1.98	98.66±0.89
	3.93	6.0	9.86	98.88±0.90	1.00	1.5	2.52	101.4±1.63
Allegra-120	3.95	2.0	5.97	101.2±0.82	1.01	0.5	1.50	98.53±1.99
	3.95	4.0	8.03	102.1±1.53	1.01	1.0	2.00	99.23±0.60
	3.95	6.0	9.89	99.10±1.40	1.01	1.5	2.53	101.6±2.53

Mean value of three determinations.