Chiral separation of sitagliptin phosphate enantiomer by HPLC using amylose based chiral stationary phase

Background

Although a number of methods are available for evaluating sitagliptin phosphate (SGP), a common method for separation if its potential enantiomer and its possible impurities with good efficiency remains unavailable. With the objective of developing a method for rapid separation with shorter runtimes, a simple, precise, accurate stability indicating normal phase High-performance liquid chromatographic (NRP-HPLC) coupled with a photodiode array detector method was developed for the quantitative determination of (S)-enantiomer in API substance and as well as drug product.

Methods

The proposed novel method uses the mixture of n-heptane-ethanol-diethylamine (DEA) 35:65:0.1 (v/v/v) as a mobile phase. The enantiomer of sitagliptin phosphate was baseline resolved on a Chiralpak AD-H (250 mm×4.6 mm, 5 μm) column. The flow rate of the mobile phase is 1.0 mL/min and the detector wavelength monitored at 265 nm. The developed method was extensively validated.

Result

In these conditions, linearity over the concentration range 400-2250 ng/ml for (S)- enantiomer was obtained. The limit of detection and quantification were 150 and 400 ng/ml, respectively. The intra and inter-day precision was less than 1.5%. The recovery of (S)- enantiomer was within 107% in bulk drug.

Conclusion

The proposed method was found to be suitable, precise, and accurate for the quantitative determination of (S)-enantiomer in bulk drugs as well as in pharmaceutical formulations.