Univariate and multivariate assisted spectrophotometric methods for determination of rosuvastatin calcium and fenofibrate in bulk powders and tablets along with their degradation products.

• No reported spectrophotometric method for determination of this quaternary mixture. • The proposed univariate methods utilize simple mathematical calculation. • Multivariate methods surpass univariate methods in solving severe overlap spectra. • Multivariate models have the advantage of being stability indicating methods. Rosuvastatin calcium and fenofibrate are recently co-formulated for treatment of hyperlipidemia. Two selective spectrophotometric approaches were developed, the first is univariate manipulation of spectrophotometric data, where isoabsorptive point and dual wavelength method were applied. The total concentration of rosuvastatin calcium and fenofibrate could be determined at λ = 253.2 nm while rosuvastatin calcium was determined with dual wavelength (λ = 243.5 and 307.9 nm) where linearity was achieved in the range of 2.00–22.00 µg/mL and mean accuracy 100.29 ± 0.568 then, by difference, Fenofibrate was determined in the range of 2.00–22.00 µg/mL and mean accuracy 100.23 ± 0.578. The second approach is a stability indicating multivariate modeling namely principal component regression and partial least squares, where the two drugs were determined in the presence of their degradation products. 17 samples were prepared according to five levels four factors calibration design. The developed models were described by 4 latent variables, and good prediction was evidenced by low root mean square error of prediction. The proposed methods were found to be rapid and simple and required no preliminary separation. Rosuvastatin calcium and fenofibrate were analyzed with mean recoveries 99.54 ± 0.903, 99.88 ± 0.548 and 99.50 ± 0.712, 99.30 ± 0.802, respectively. The two drugs were successfully determined in tablets by the developed methods and the results were compared to HPLC methods, where they were found to be statistically non-significant. [ABSTRACT FROM AUTHOR]