To develop an HPLC method for the separation of perindopril tert-butylamine and its epimer [(±)-1”-epi-perindopril tert-butylamine] and the determination of the epimer.

Perindopril and (±)-1”-epi-perindopril were separated on an Agilent Poroshell CS-C₁₈ column (100 mm×3.0 mm, 2.7 μm) maintained at 50 ℃ with the mobile phase containing a mixture of 0.15% sodium heptanesulfonate solution (adjusted to pH 2.0 with phosphoric acid) and acetonitrile-pentanol(217∶3)(82∶18, V/V) at 0.8 mL·min^-1, and the detection wavelength was set at 215 nm. The injection volume was 2 μL.

(±)-1”-epi-perindopril and perindopril were separated successfully in 25 min with peak to valley ratio more than 3.0 or a resolution factor of 1.7. Good linear relationships were established between the peak response and the concentration in the range of 2-2 000 μg·mL^-1 for the epimer and perindopril tert-butylamine(r>0.999). The quantitative limits(S/N= 10) were both about 1.0 μg·mL^-1, and the detection limits(S/N=3) were both 0.3 μg·mL^-1. The spiked recovery of the epimerer was 97.2% (RSD=1.8%, n=9). The content of (±)-1”-epi-perindopril tert-butylamine in 10 batches of samples ranged from 0.025% to 0.078%.

The proposed method enhances the resolution efficiency, shows high accuracy, repeatability and stability. It can be effectively employed for the quality control of perindopril tert-butylamine．