1 Stationary phase Phenomenex C18 analytical column,
(250 mm×4.6 mm, 5 μm)
2 Mobile phase Solvent A: Ammonia solution adjusted the pH to 4.5 with ortho phosphoric acid
Solvent B: Buffer: ACN (45:55 v/v)
3 Flow rate 1.2 ml/min
4 Detection wavelength 240 nm
5 Injection volume 20 µl
6 Temperature Ambient temperature
Table 1: The optimized chromatographic conditions for analysis of lopinavir and ritonavir.