Table 3.

Determination of atorvastatin in Lipitor^® tablets (20 mg) by the proposed spectrofluorimetric methods.

Spectrofluorimetric method using acetate buffer (pH 3.4)			Spectrofluorimetric method using 5% acetic acid			Spectrofluorimetric method using methanol
Known concentration (μg/mL)	Concentration found (μg/mL)	Recovery (%)	Known concentration (μg/mL)	Concentration found (μg/mL)	Recovery (%)	Known concentration (μg/mL)	Concentration found (μg/mL)	Recovery (%)
2.00	1.97	98.62	2.00	1.99	99.75	1.00	1.03	102.92
2.50	2.59	103.44	3.00	3.02	100.60	1.50	1.47	98.03
3.00	3.15	105.10	4.00	4.02	100.53	2.00	1.96	98.18
3.50	3.59	102.67				2.50	2.54	101.47
4.00	3.99	99.95				3.00	3.12	104.09
Mean		101.96			100.29			100.94
N		5.00			3.00			5.00
SD		2.64			0.47			2.75
R.S.D. (%)		1.16			0.27			1.22