Development of UV Spectrophotometric Procedures for Determination of Amlodipine and Celecoxib in Formulation: Use of Scaling Factor to Improve the Sensitivity

Table 3

Recovery study results by the standard addition method.

	First derivative method		Second method
	Amount added (μg/ml)	% Recovery	Amount added (μg/ml)	% Recovery
AMD	1	98.87	1	98.49
	2	100.94	2	101.12
	3	99.09	3	99.44
	Across mean	99.63		99.68
	% RSD	1.14		1.33
COX	5	101.23	5	99.17
	10	98.77	10	101.39
	15	99.06	15	99.28
	Across mean	99.69		99.95
	% RSD	1.34		1.25