Biological Safety Studies and Simultaneous Determination of Linagliptin and Synthetic Impurities by LC-PDA

Figure 3

Chromatograms obtained during specificity study. (a)–(e) Drug product (20 µg·mL⁻¹): (a) photodegradation (UVA, 4 h); (b) oxidative degradation (30% H₂O₂); (c) basic hydrolysis (1.0 mol/L NaOH) at 80°C; (d) acid hydrolysis (1.0 mol/L HCl) at 80°C; (e) dry heat at 60°C. Impurity 1 (peak 1; 3.91 min); LGT (peak 2; 5.52 min); impurity 2 (peak 3; 7.47 min); impurity 3 (peak 4; 8.42 min).

(a)

(b)

(c)

(d)

(e)