Estimation of Tadalafil Using Derivative Spectrophotometry in Bulk Material and in Pharmaceutical Formulation

Table 5

Ruggedness studies.

Drug	Methods	Analyst I		Analyst II
		% Amount found ± SD  [𝑛=3]	% RSD	% Amount found ± SD  [𝑛=3]	% RSD
Tadalafil	A	101.27±0.90	0.89	100.75±0.45	0.44
	B	100.55±0.18	0.18	99.90±0.11	0.11
	C	101.47±0.40	0.39	101.41±0.29	0.28
	D	99.05±0.58	0.59	99.61±1.10	1.11

𝑛: number of estimations.