Spectrophotometric methods based on charge transfer complexation reactions for the determination of saxagliptin in bulk and pharmaceutical preparation

Abstract

Simple, accurate and precise spectrophotometric methods have been developed for the determination of saxagliptin in bulk and dosage forms. The proposed methods are based on the charge transfer complexes of saxagliptin with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and 7,7,8,8-tetracyanoquinodimethane (TCNQ). All the variables were studied to optimize the reactions' conditions. Beer's law was obeyed in the concentration ranges of 50-300 μg/ml and 10-110 μg/ml with DDQ and TCNQ, respectively. The developed methods were validated and proved to be precise and accurate for the quality control of the saxagliptinin its pharmaceutical dosage form.

Keywords: charge transfer reactions; pharmaceutical preparation; saxagliptin; spectrophotometry.

Figure 1

Chemical structure of saxagliptin.

Figure 2

A bsorption s pectra of t he c olored p roduct of s axagliptin (2.7 × 10^-3 M) and DDQ (16.2 × 10^-3 M) in methanol (a), saxagliptin (2.7 × 10^-3 M) in methanol (b) and DDQ (16.2 × 10^-3 M) in methanol (c).

Figure 3

Absorption spectra of the colored product of TCNQ (5.4 × 10^-3 M) with saxagliptin (2.7 × 10^-3 M) in methanol (a), saxagliptin (2.7 × 10^-3 M) in methanol (b), TCNQ (5.4 × 10^-3 M) in methanol (c).

Figure 4

Effect of the reaction time in the determination of saxagliptin with DDQ (series 1) and TCNQ (series 2).

Figure 5

Effect of stability of the formed charge transfer complex in the determination of saxagliptin with DDQ (series 1) and TCNQ (series 2).

Figure 6

Effect of the amount of the reagent in the determination of saxagliptin with DDQ (series 1) and TCNQ (series 2).

Figure 7

Continuous variation plot of the reaction products of saxagliptin with DDQ (—) and TCNQ (----).