چکیده (انگلیسی):

New simple and sensitive spectrophotometric and spectrofluorimetric methods have been
developed and validated for the determination of saxagliptin (SAX) and vildagliptin (VDG) in bulk
and pharmaceutical preparations. The spectrophotometric methods were based on derivatization of
the investigated drugs with two reagents: 1,2-naphthoquinone-4-sulfonic acid sodium salt (NQS)
and 4-chloro-7-nitrobenzofurazan (NBD-Cl). For further increase in the sensitivity, the D1 spectra
of the reactions products were also recorded. For NQS reaction, Beer’s law was obeyed over the
ranges of 5–30 and 7–45 lg mL1 for the absorbance readings; and 3–32 and 5–50 lg mL1 for
the derivative readings of SAX and VDG, respectively. For NBD-Cl reaction, Beer’s law was
obeyed over the ranges of 3–20 and 4.5–35 lg mL1 for the absorbance readings; and 1.5–25 and
2.5–40 lg mL1 for the derivative readings of SAX and VDG, respectively. Spectrofluorimetric
methods were developed based on the fact that the derivatized investigated drugs with NBD-Cl
reagent are highly fluorescent products. The fluorescence concentration plots were linear over the
ranges of 0.02–0.25 and 0.03–0.37 lg mL1 for SAX and VDG, respectively. The fluorescence measurement
enabled the detection of SAX and VDG at concentrations of about 3 and 7 ng mL1,
respectively. The proposed methods have been validated and successfully applied to the determination
of the investigated drugs in their pharmaceutical preparations. The results obtained were statistically
compared to those obtained from reference methods.