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

Table 1

Optical characteristics of tadalafil.

Parameters	Method A	Method B	Method C	Method D
Beer-Lambert’s range (𝜇g/mL)	05–50	05–50	20–70	20–70
𝜆 max (nm)/wavelength range (nm)	297	290.60–304.40	284	280.80–286.20
Slope	0.0064	0.0380	0.0013	0.0015
Intercept	−0.0123	−0.0269	−0.0178	0.0151
Correlation coefficient	0.9993	0.9993	0.9990	0.9991