Abstract

A stability-indicating LC method for the determination of the antihyperglycemic agent sitagliptin phosphate in tablets was developed and validated using the Plackett-Burman experimental design for robustness evaluation and determination of the system suitability limits. Analytical parameters were studied according to International Conference on Harmonization (ICH) guidelines. The analytical column was operated with a solution of triethylamine 0.3% and acetonitrile (75:25, v/v), adjusted to pH 4.0 at a flow rate of 1.0 mL min-1 and detection at 207 nm, maintained at 25 °C. In forced degradation studies, the effects of acid and basic media with HCl 1M and NaOH 1M, respectively, oxidation, exposure to UV-C light and temperature 60°C were investigated, showing no interference in the drug peak, and the possible breaches of sitagliptin after degradation were suggested by mass analysis. The method was linear (r = 0.9993) at a concentration range from 70.0 to 130.0 μg mL-1 and ANOVA showed a non-significant linearity deviation (p>0.05). Adequate results were obtained for precision (inter and intra-day) and accuracy. Critical factors were selected to examine the method robustness with the two-level Plackett-Burman experimental design and no significant factors were detected (p>0.05). The sitagliptin cytotoxicity assay was determined for the degraded sample in methanolic solution, under UV-C light at 254 nm.

Keywords: Cytotoxicity, Liquid Chromatography, Mass Spectrometry, Plackett-Burman, Sitagliptin, Stability-Indicating