The analysis was carried out using a Zorbax Eclipse XDB-C18 (4.6 × 150 mm, 3.5 μm) with a column guard. The mobile phase consisted of acetonitrile: water (50: 50) and the flow rate was 1 mL/min, the detection wavelength was 227 nm, the injection volume 5 μL and the analysis was performed at room temperature.
The method was validated according ICH guidelines and FDA guidelines for validation of bioanalytical methods. Linearity was evaluated in the range from 0.005 – 50.0 μg/mL, with a regression coefficient (R2) of 0.9967. LOD and LOQ were 0.001 and 0.005 μg/mL respectively.