5 + 100, 200 + 1.0 + 200, 300 + 1.5 + 300, 400 + 2.0 + 400, 500 + 2.5 + 500 μg/ml of GBP + MCB + ALP recorded in spectroscopic condition. For ratio spectra of GBP, standard spectra of the drugs mixture were divided by spectra of 0.5 μg/ml

MCB and 100 μg/ml ALP. Ratio spectra of GBP were smoothed (Δλ = 10) and converted to first order derivative spectra (Δλ = 10, SF = 10). For ratio spectra of MCB standard spectra of the drugs mixture were divided by spectra of 100 μg/ml GBP and 100 μg/ml ALP. Ratio spectra of MCB were smoothed (Δλ = 10) and converted to first order derivative spectra (Δλ = 10, SF = 10). For ratio spectra of ALP, standard spectra of the drugs mixture were divided by spectra of 0.5 μg/ml MCB and 100 μg/ml GBP. Ratio spectra of ALP were smoothed (Δλ = 10) Luminespib and converted to first order derivative spectra (Δλ = 10, SF = 1). Amplitudes (dA/dλ) of obtained ratio derivative spectra of the drugs were measured at selected wavelengths. Standard calibration curves of dA/dλ against Concentration were plotted. Validation of developed method was carried out according to ICH

Guideline for Epacadostat in vitro Validation of Analytical Procedures Q2 (R1) by linearity, limit of detection (LOD) and limit of quantitation (LOQ), accuracy, Precision, robustness and specificity. Solution containing mixture of 300 μg/ml of GBP, 1.5 μg/ml of MCB and 300 μg/ml ALP was prepared and analyzed as per proposed method with small but deliberate change in spectroscopic condition such as scanning speed, filter variability (0.25 μm and 0.45 μm) and methanol from different manufacturers. The mean amplitude (dA/dλ) with its standard deviation and % relative

standard deviation was computed at each level. Specificity of an analytical method Idoxuridine was assessed by, defining its ability to measure accurately and specifically the analyte of interest without interferences from blank: Solution containing 300 μg/ml GBP, 1.5 μg/ml MCB, 300 μg/ml ALP, mixture of 300 μg/ml GBP, 1.5 μg/ml MCB and 300 μg/ml ALP were prepared and analyzed as per the proposed method. Solution containing mixture of 300 μg/ml of GBP, 1.5 μg/ml of MCB and 300 μg/ml ALP was prepared. Prepared solution is analyzed after 24 h for stability of drugs in 0.1 N HCl, 0.1 N NaOH, light, thermal and hydrogen peroxide. Twenty tablets were weighed accurately and their average weight was determined. The tablets were crushed to fine powder and from the triturate, tablet powder equivalent to 25 mg of GBP, 0.125 mg MCB and 25 mg of ALP were weighed and transferred to 25 ml volumetric flask. To this flask, 15 ml methanol was added and the flask was sonicated for 5 min. The volume was adjusted up to the mark with methanol. The solution was then filtered through membrane filter paper (0.25 μm). Filtrate contained mixture of 1000 μg/ml GBP, 5 μg/ml MCB and 1000 μg/ml ALP. The filtrate solution was suitably diluted with methanol to get a final concentration of 300 μg/ml of GBP, 1.