Univariate and Multivariate Determination of Dapagliflozin and Saxagliptin in Bulk and Dosage Form

Dapagliflozin is a sodium glucose cotransporter-II inhibitor while saxagliptin is a dipeptidyl peptidase-4 inhibitor. Both are used to manage type 2 diabetes mellitus.

The aim of this work is to develop four simple, accurate, and precise UV-spectrophotometric methods, three univariate and one multivariate, for the estimation of dapagliflozin and saxagliptin in their pure and marketed dosage forms.

Method (A) is based on the ratio difference method; Method (B) is ratio subtraction with constant multiplication; while Method (C) is a second derivative method and Method (D) is a partial least-squares method.

The calibration curves for dapagliflozin and saxagliptin were linear within the concentration range of 2.50-50.0 μg/mL and 5.0-60.0 μg/mL, respectively. The specificity of the proposed methods was studied by analyzing different laboratory-prepared mixtures and their combined pharmaceutical dosage form. According to the International Council for Harmonisation guidelines, the three proposed methods were validated regarding the accuracy, precision, and specificity. Method (D), partial least-squares, was employed for the determination of the same mixture over a wavelength range of 205-300 nm. A statistical comparison was performed between the results of the proposed methods and those of a reported spectrophotometric method and no statistically significant difference was detected at 95% confidence limit regarding both precision and accuracy.

Four accurate, specific, and precise UV-spectrophotometric methods for dapagliflozin and saxagliptin testing and estimation were successfully utilized and validated.

The examined methods are simple and do not involve sophisticated and expensive instruments. They could be effectively employed in quality control laboratories for routine examination of the investigated drugs in their pure powdered or combined pharmaceutical formulations.