Table 4 Validation parameters and results obtained by the proposed HPLC–DAD method for the simultaneous determination of ASP, ROS, ATV and CLP

Retention time (t_R) (min)

1.27

4.45

5.55

6.90

Wavelength of detection (nm)

230

230

230

230

Range of linearity (μg/mL)

0.05–50

0.05–50

0.05–50

0.05–50

Regression equation

AUP^a 210 nm = 1.1345 C_ASP + 0.3893

AUP 210 nm = 1.0273 C_ROS + 0.0251

AUP 210 nm = 1.8642 C_ATV + 0.1093

AUP 210 nm = 0.7693 C_CLP + 0.0067

Regression coefficient (r²)

0.9997

0.9997

0.9999

1

LOD (μg/mL)^b

0.002

0.009

0.010

0.012

LOQ (μg/mL)^c

0.006

0.027

0.032

0.037

Standard deviation of slope (S_b)

0.00777

0.00680

0.00668

0.00139

Standard deviation of the intercept (S_a)

0.18486

0.16199

0.15899

0.03310

Confidence limit of the slope

1.1345 ± 0.0183

1.0273 ± 0.0161

1.8642 ± 0.0158

0.7693 ± 0.0033

Confidence limit of the intercept

0.3893 ± 0.436

0.0251 ± 0.382

0.1093 ± 0.375

0.0067 ± 0.078

Standard error of estimation

0.36722

0.32179

0.31583

0.06574

^dIntra-day % RSD

0.002–0.408

0.027–0.669

0.121–0.309

0.053–0.481

^eInter-day % RSD

0.296–0.512

0.222–0.595

0.291–0.415

0.115–0.813

Drug in dosage form

99.02 ± 0.112

99.56 ± 0.222

100.02 ± 0.142

100.14 ± 0.044

Drug added

99.45 ± 0.244

99.73 ± 0.347

98.99 ± 0.025

99.36 ± 0.012