Parameter CARV HCT 3D 4D 1DD 3D 4D 1DD Wavelength (nm) 245.9 247.4 236.1 230.2 226.9 261.1 Concentration range (µg.mL-1) 0.5- 20.0 0.5- 18.0 Regression equation (Y)a             Slope (b) 0.084 0.064 1.326 0.027 0.017 1.030 Intercept (a) 0.019 0.020 0.080 0.006 0.004 0.099 Correlation coefficient (r) 0.9996 0.9997 0.9998 0.9996 0.9996 0.9997 Accuracy (mean%, n=12) 97.23 99.25 98.32 97.50 97.13 98.52 Intraday precision (RSD%,n=12) 0.50 0.48 0.57 0.37 0.36 0.49 Interday precision (RSD%,n=12) 0.53 0.40 0.53 0.42 0.54 0.56 LOD (µg.mL-1) 0.15 0.16 0.13 0.16 0.14 0.11 LOQ (µg.mL-1) 0.45 0.48 0.39 0.48 0.42 0.33 a Y= a + bX, where Y is the amplitude and X is the drug concentration (μg.mL-1)

Table 5: Validation and application of the suggested methods for determination of CARV and HCT in spiked human plasma using 3D, 4D and 1DD methods.