Table 2 Regression and validation data for the determination of atorvastatin calcium and vitamin D₃

Wavelength (nm)

246

264

Linearity range (µg/ml)

5–40

1–8

LOD (µg/ml)

0.48

0.04

LOQ (µg/ml)

1.43

0.12

Regression equation (y = ax + b)

 Slope (a)

11,949

13,724

 Intercept (b)

60,912

− 1251.5

 Coefficient of determination (r²)

0.9998

0.9995

Robustness (% R ± % RSD)

 ▲λ (± 2 nm)

99.99 ± 0.27

99.49 ± 0.45

 Ethanol (± 1%)

98.42 ± 1.75

99.13 ± 0.77

 PH (± 0.1)

97.13 ± 2.57

99.34 ± 0.63