Simultaneous Spectrophotometric Determination of Diflunisal and Diclofenac Sodium in Pharmaceutical Dosage Form Using Chemometric Methods

Aims: Is the simultaneous determination of Diflunisal and Diclofenac sodium in pharmaceutical preparations.

Study Design: Four spectrophotometric methods (Classical Least Squares, Iterative Target Transformation Factor Analysis, Principal Component Regression and Partial Least Squares) will be described and evaluated for the simultaneous determination of the two drugs. In these techniques, the concentration data matrix was prepared according to the full factorial experimental design of three levels and two components in mixtures.

Place and Duration of Study: Microanalytical Chemistry Laboratory, Applied Organic Chemistry Department, National Research Centre, Dokki, Giza, Egypt, between January 2016 and Marsh 2016.

Methodology: Using 2.5 mM NaOH solution as solvent, the corresponding absorbance data matrix was measured over the wavelength range of 220 – 400 nm with the intervals of Δλ= 1 nm, then regression was obtained by using the absorbance data matrix and the concentration data matrix for the prediction of the unknown concentrations of Diflunisal and Diclofenac sodium in their mixture. The procedure did not require any chemical separation step or prior graphical treatment of the overlapped spectra.

Results: The calibration range was found linear over 2.5 – 20 μg/mL for Diflunisal and Diclofenac sodium through the Partial Least Squares method.

Conclusion: The Partial Least Squares method was selected and validated on both authentic mixtures and pharmaceutical preparations. The accuracy and precision of the methods were assessed and compared with each other.