Gradient RP-HPLC method for the determination of potential impurities in atazanavir sulfate.

This paper proposes a simple and selective RP-HPLC method for the determination of process impurities and degradation products (degradants) of atazanavir sulfate (ATV) drug substance. Chromatographic separation was achieved on Ascentis(®) Express C8, (150mm×4.6mm, 2.

Impurity profile study of lopinavir and validation of HPLC method for the determination of related substances in lopinavir drug substance.

Several related substances (RS4-RS10) were detected in lopinavir drug substance at levels ranging from 0.03% to 0.1% by employing gradient RP-HPLC.