Stability Indicating RP-HPLC Method for the Determination of Process Related Impurities in Posaconazole API

The objective of the current study was to develop a validated, specific and stability-indicating reversed phase HPLC method for the quantitative determination of posaconazole and its related substances in API (Active Pharmaceutical Ingredient). The determination was done for active pharmaceutical ingredient in the presence of degradation products, and its process-related impurities. The chromatographic separation was achieved on a waters HPLC system with PDA detector and the column employed for the present investigation was inertsil ODS-3V C18 (150×4.6 mm with 5 μ particle size) and empower2 software provided by waters was used throughout the experiment. The method employed a linear gradient elution and the detection wavelength was set at 225 nm (for intermediate A impurity) and 260 nm (for intermediate B, diastereomer, formyl and benzyl posaconazole impurity). The drug was subjected to stress conditions of hydrolysis (acid and base), oxidation, photolysis and thermal degradation as per International Conference on Harmonization (ICH) prescribed stress conditions to show the stability-indicating power of the method. Significant degradation was observed during acid, oxidative, thermal and photo stress studies. In the developed HPLC method, the resolution between posaconazole and its process-related impurities was found to be greater than 2.0. Regression analysis shows an r value (correlation coefficient) of greater than 0.999 for posaconazole and it’s all the five impurities. The developed HPLC method was validated with respect to linearity, accuracy, precision and robustness.